PT6A-60 SERIES TRAINING MANUAL November 2007 Pratt & Whitney Canada © 1999-2007 Pratt & Whitney Canada, Inc

PREFACE

STUDENT: ______

INSTRUCTOR:______

PT6A-60 SERIES TRAINING USE ONLY PREFACE I P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface DISCLOSURE

WARNING - PROPRIETARY RIGHTS NOTICE This document is the property of Pratt & Whitney Canada Corp. “(P&WC)”. You may not possess, use copy or disclose this document or any information in it, for any purpose, including without limitation to design, manufacture or repair parts, or obtain FAA or any other government approval to do so, without P&WC’s express written permission. Neither receipt or possession of this document alone, from any source constitutes such permission. Possession, use, copying or disclosure by anyone without P&WC’s express written permission is not authorized and may result in criminal or civil liability

NOTICE - DISCLOSURE OF INFORMATION This document contains trade secrets or other confidential information, the further disclosure of which may be harmful to Pratt & Whitney Canada Corp. if the head of a government agency or department intends to disclose any of this information, written notice should be given to: the Vice President - Legal Services, Pratt & Whitney Canada Corp., 1000 Marie Victorin (01BE5), Longueuil, Quebec J4G 1A1

PT6A-60 SERIES TRAINING USE ONLY PREFACE II P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface PRATT & WHITNEY CANADA

The Customer Training Centre, Pratt and Whitney Canada, Longueuil, Quebec, Canada issued this document. This document is to be used for Training Use Only. The data contained herein does not replace or supersede the information contained in the appropriate airframe or engine maintenance manuals or other official publications.

For information concerning this manual, contact the P&WC Customer Training Department, by : Tel: 1-450-468-7774, Fax: 1-450-468-7824, or Email: [email protected]

P&WC Customer Training course schedule and registration on Internet: http://www.pwccustomertraining.ca

For technical queries, contact the P&WC technical support Customer First Centre (CFC) (24 HOUR SERVICE): Telephone : (USA & Canada)1-800-268-8000 International Direct Access :1-8000-268-8000 General :1-450-647-8000 Fax :1-450-647-2888 Pratt & Whitney Canada on the Internet : http://www.pwc.ca

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PT6A-60 SERIES TRAINING USE ONLY PREFACE IV P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface TABLE OF CONTENT

PREFACE ...... I COMPRESSOR INLET CASE ...... 2.6-2.7 DISCLOSURE...... II COMPRESSOR ...... 2.8-2.9 PRATT & WHITNEY CANADA...... III-IV COMPRESSOR WASH ...... 2.10-2.11 TABLE OF CONTENT...... V-VIII COMPRESSOR BLEED VALVE ...... 2.12-2.15 PRE-SWIRL SYSTEM ...... 2.16-2.19 INTRODUCTION ...... IX BLEED VALVE CLOSING POINT ...... 2.20-2.23 SCOPE ...... X GAS GENERATOR CASE ...... 2.24 ABBREVIATIONS ...... XI GAS GENERATOR CASE / DIFFUSER ...... 2.25 ENGINES COVERED IN THIS MANUAL ...... XII COLD SECTION TROUBLESHOOTING ...... 2.26 PT6 GENERAL NOTES...... XIII MAJOR ENGINE DIFFERENCES ...... XIV-XV CHAPTER 3 - COMBUSTION & TURBINE ...... 3.1 P&WC PUBLICATIONS ...... XVI HOT SECTION...... 3.2 PUBLICATION STANDARDS...... XVII-XVIII HOT SECTION AREA...... 3.3 SERVICE BULLETIN COMPLIANCE CODES..... XIX COMBUSTION CHAMBER LINER & SMALL EXIT DUCT...... 3.4-3.5 CHAPTER 1 - ENGINE OVERVIEW...... 1.1 COMPRESSOR TURBINE VANE RING...... 3.6-3.9 PT6A-61 RIGHT FRONT VIEW ...... 1.2 COMPRESSOR TURBINE ...... 3.10-3.11 PT6A-64 LEFT FRONT VIEW ...... 1.3 COMPRESSOR TURBINE TRIM BALANCING... 3.12 PT6A-60 RIGHT FRONT VIEW ...... 1.4 COMPRESSOR TURBINE ...... 3.13 PT6A-67 LEFT VIEW...... 1.5 ALTERNATE TRIM WEIGHTS (64/66/67)...... 3.14 MAJOR ASSEMBLIES AND FLANGES ...... 1.6-1.7 ALTERNATE TRIM WEIGHTS ...... 3.15 FEATURES ...... 1.8 POWER TURBINE VANE RINGS...... 3.16-3.17 GENERAL TURBOPROP OPERATION ...... 1.10 POWER TURBINES ...... 3.18-3.19 TURBOPROP ENGINE ...... 1.11 TURBINE WASH...... 3.20-3.21 MAIN ENGINE BEARINGS...... 1.12 EXHAUST DUCT & PT SHAFT HOUSING...... 3.22-3.23 BEARINGS ...... 1.13 HOT SECTION SEALING ...... 3.24-3.27 STATIONS...... 1.14-1.15 HOT SECTION TROUBLESHOOTING...... 3.28 ENGINE EXTERNAL COMPONENTS ...... 1.16-1.19

CHAPTER 2 - COMPRESSOR SECTION ...... 2.1 COMPRESSOR SECTION...... 2.2-2.3 INERTIAL SEPARATOR (AIRFRAME)...... 2.4 INERTIAL SEPARATOR (TYPICAL) ...... 2.5

PT6A-60 SERIES TRAINING USE ONLY TABLE OF CONTENT V P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface TABLE OF CONTENT (CONT’D)

CHAPTER 4 - GEARBOXES...... 4.1 CHAPTER 8 - IGNITION SYSTEM...... 8.1 REDUCTION GEARBOX...... 4.2-4.3 IGNITION SYSTEM ...... 8.2-8.3 STANDARD ROTATION REDUCTION GEARBOX4.4 PT6A-66 REVERSE ROTATION GEARBOX ...... 4.5 CHAPTER 9 - PERFORMANCE ...... 9.1-9.2 ACCESSORY GEARBOX ...... 4.6-4.7 ENGINE PERFORMANCE CHECK (TYPICAL)9.3 PIN LOCK ARRANGEMENT ...... 4.8 PERFORMANCE CHECK (SHORTS INSTALL)9.4-9.6 ACCESSORY GEARBOX ...... 4.9 WebECTM...... 9.7-9.8 ECTM SAMPLE PLOT ...... 9.9 CHAPTER 5 - OIL SYSTEM...... 5.1-5.7 TBO & HSI INTERVAL ...... 9.10 OIL PRESSURE REGULATION & FILTRATION.. 5.8-5.9 OPERATING LIMITS* ...... 9.11-9.18 THERMOSTATIC BYPASS ROTOR COMPONENTS - SERVICE LIFE ...... 9.19 & CHECK VALVE ...... 5.10-5.11 OVERTORQUE CHART (TYPICAL) ...... 9.20 OIL SYSTEM TROUBLESHOOTING ...... 5.12-5.13 OVERTEMPERATURE CHART (TYPICAL)..... 9.21 ENGINE TROUBLESHOOTING ...... 9.22 CHAPTER 6 - SECONDARY AIR SYSTEM...... 6.1-6.3 PERFORMANCE TROUBLESHOOTING ...... 9.23-9.27 ACCESSORY GEARBOX BREATHER...... 6.4-6.5 OIL TANK PRESSURIZING VALVE ...... 6.6-6.7 CHAPTER 10 - FUEL SYSTEM ...... 10.1 TURBINE COOLING POWER MANAGEMENT...... 10.2-10.3 AND AIRBLEED SYSTEM...... 6.8-6.9 FUEL SYSTEM ...... 10.4-10.6 BEARING COMPARTMENT SEALING ...... 6.10-6.11 FUEL SYSTEM SCHEMATIC ...... 10.7 FUEL HEATER...... 10.8-10.9 CHAPTER 7 - ENGINE INDICATING SYSTEM .. 7.1-7.3 FUEL PUMP ...... 10.10-10.11 INTER-TURBINE TEMPERATURE (T5)...... 7.4 FUEL CONTROL UNIT (MAIN FLOW) ...... 10.12-10.13 TEMPERATURE INDICATING SYSTEM (T5) ..... 7.5 FUEL METERING SECTION...... 10.14-10.15 TEMPERATURE INDICATING SYSTEM (ITT) .... 7.6 METERING SECTION (3D CAM) ...... 10.16 T5 SYSTEM SCHEMATIC...... 7.7 FUEL CONTROL SYSTEM...... 10.17 TORQUE SYSTEM...... 7.8-7.9 COMPRESSOR DELIVERY AIR LINES ...... 10.18 CHIP DETECTOR...... 7.10-7.11 P3 AIR FILTER ELEMENT...... 10.19 FLOW DIVIDER WITH DUMP VALVE...... 10.20-10.21 FLOW DIVIDER WITH PURGE VALVE ...... 10.22-10.23 FLOW DIVIDER WITH DUMP VALVE...... 10.20-10.21

PT6A-60 SERIES TRAINING USE ONLY TABLE OF CONTENT VI P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface TABLE OF CONTENT (CONT’D)

FLOW DIVIDER WITH PURGE VALVE ...... 10.22-10.23 HOT SECTION TOOLS...... 12.8-12.9 SIMPLEX FUEL NOZZLES...... 10.24-10.25 CT TIP CLEARANCE MEASUREMENT...... 12.10 DUPLEX FUEL NOZZLES...... 10.26-10.27 HOT SECTION INSPECTION (CONT’D)...... 12.12 FUEL CONTROL UNIT MANUAL OVERRIDE .10.28 CT BLADE SULPHIDATION ...... 12.13 FCU MANUAL OVERRIDE ...... 10.29 HOT SECTION INSPECTION (CONT’D)...... 12.14-12.19 POWER RECOVERY SYSTEM...... 10.30-10.31 OVERTORQUE LIMITER...... 10.32-10.33 CHAPTER 13 - RIGGING...... 13.1 FUEL CONTROL UNIT ADJUSTMENT...... 10.34-10.35 BASIC ENGINE RIGGING...... 13.2 FUEL SYSTEM REAR LINKAGE RIGGING ...... 13.3 TROUBLESHOOTING SUMMARY...... 10.36 WOODWARD FUEL CONTROL RIGGING...... 13.4 REAR LINKAGE (WOODWARD) ...... 13.5 CHAPTER 11- PROPELLER SYSTEM...... 11.1-11.3 FRONT LINKAGE RIGGING...... 13.6 PITCH CHANGE MECHANISM...... 11.4-11.5 FRONT LINKAGE ...... 13.7 PROPELLER GOVERNOR FUEL CONDITION LEVER...... 13.8 GOVERNING MODE ...... 11.6-11.7 FUEL & PROPELLER LEVER RIGGING...... 13.9 PROPELLER GOVERNOR...... 11.8 POST RUN UP ADJUSTMENTS ...... 13.10-13.11 BETA MODE (FORWARD OPERATION)...... 11.9 TWIN ENGINE RIGGING PROPELLER GOVERNOR...... 11.10-11.12 TROUBLESHOOTING ...... 13.12 BETA MODE (REVERSE OPERATION)...... 11.13 POST RUN-UP ADJUSTMENTS PROPELLER FEATHERING...... 11.14-11.15 (TWIN ENGINE)...... 13.13 NF GOVERNOR ...... 11.16-11.17 PROPELLER OVERSPEED GOVERNOR ...... 11.18-11.19 PROPELLER GOVERNOR ADJUSTMENTS ...... 11.21-11.23 PRIMARY BLADE ANGLE (PBA) CHECK...... 11.24 PRIMARY BLADE ANGLE CHART ...... 11.25 PROPELLER SYSTEM TROUBLESHOOTING11.26

CHAPTER 12 - MAINTENANCE PRACTICES.12.1 PERIODIC INSPECTION...... 12.2-12.3 HOT SECTION INSPECTION ...... 12.4 BORESCOPE INSPECTION ...... 12.6 GUIDE TUBE ORIENTATION ...... 12.7

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PT6A-60 SERIES TRAINING USE ONLY TABLE OF CONTENT VIII P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface INTRODUCTION

INTRODUCTION

PT6A-60 SERIES TRAINING USE ONLY INTRODUCTION IX P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface SCOPE

This training guide contains information pertaining to the description, operation, maintenance and troubleshooting of the PT6A-52 /60A / 60AG / 61 / 64 / 65AG / 65AR / 65B / 65R / 66 / 66A / 66B / 66D / 67 / 67A / 67AF / 67AG / 67AF / 67AR / 67B / 67D / 67F / 67P /67R engines. This training guide is intended for training use only and includes cross section drawings, schematics and text.

A basic understanding of jet engine principle would be an asset.

This guide may be used for Line Maintenance or Heavy Maintenance training.

PT6A-60 SERIES TRAINING USE ONLY INTRODUCTION X P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface ABBREVIATIONS

AG Agricultural Palt Pressure Altitude AGB Accessory Gearbox Pamb Ambient Air Pressure AMM Airframe Maintenance Manual PBA Primary Blade Angle BOV Bleed Off Valve PLA Power Lever Angle CCW Counterclockwise PPH Pounds Per Hour CW Clockwise PSI Pounds Per Square Inch CSU Constant Speed Unit (Prop Governor) PSIA Pounds Per Square Inch Absolute CT Compressor Turbine PSID Pounds Per Square Inch Differential ECTM Engine Condition Trend Monitoring PSIG Pounds Per Square Inch Gage ESHP Equivalent Shaft Horsepower PT Power Turbine FCU Fuel Control Unit Px Modified P3, After A Restrictor FI Flight Idle (High Idle) Py Modified Px, After A Restrictor FOD Foreign Object Damage RGB Reduction Gearbox GI Ground Idle (Low Idle) S/N Serial Number HSI Hot Section Inspection SB Service Bulletin IAS Indicated Air Speed SIL Service Information Letter IBR Integrally Bladed Rotor SFC Specific Fuel Consumption ISA International Standard Atmosphere SHP Shaft Horsepower ITT Interturbine Temperature (T5) T/O Take-Off MM Maintenance Manual T5 Temperature At Station 5 (ITT) MOP Main Oil Pressure TBO Time Between Overhaul MOT Main Oil Temperature Tq Torque Nf Free Turbine Speed Wa Air Mass Flow Ng Gas Generator Speed (N1) Wf Fuel Flow Np Propeller Speed (N2) OAT Outside Air Temperature Bold highlights indicate engine parameters OSG Overspeed Governor P0 Bypass Fuel Pressure P1 Fuel Pump Delivery Pressure P2 Metered Fuel Pressure P2.5 Compressor (axial stage) discharge pressure (station 2.5) P3 Compressor Discharge Pressure (Station 3)

PT6A-60 SERIES TRAINING USE ONLY INTRODUCTION XI P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface ENGINES COVERED IN THIS MANUAL

Weight Certification Engine Model SHP Aircraft (Lbs) Date PT6A-52 850 430 April 2007 Blackhawk B200GT PT6A-60A 1050 475 May 1983 Beech KA 300/350 PT6A-60AG 1050 500 May 1995 Air Tractor AT-602, Ayres PT6A-61 850 429 March 1983 Piper Cheyenne IIIA PT6A-64 700 472 April 1990 Socata TBM 700 PT6A-65B 1100 495 December 1992 Beech 1900 C PT6A-65R 1376 496 August 1982 Shorts 360 PT6A-65AG 1300 501 March 1985 Air Tractor AT-602, Ayers Turbo Thrush PT6A-65AR 1424 501 January 1984 Shorts 360 PT6A-66 850 469 & 483 July 1986 Piaggio Avanti PT6A-66A 850 456 December 2003 AeroVodochody Ae 270HP PT6A-66B 850 460 March 2006 Piaggio Avanti II PT6A-66D 850 458 November 2005 TBM 850 PT6A-67 1200 520 November 1986 Beech Starship PT6A-67A 1200 520 January 1988 Beech Starship PT6A-67AG 1350 525 July 1998 Air Tractor AT-802AF PT6A-67AF 1424 552 November 1987 Conair IMP S-2 PT6A-67B 1200 538 October 1990 Pilatus PC-12 PT6A-67D 1279 534 December 1991 Beech 1900 D PT6A-67F 1600 550 June 2007 Air Tractor AT-1002 PT6A-67P 1200 550 September 2007 Pilatus PC12 Next Generation PT6A-67R, A-67AR 1424 534 December 1991 Shorts 360, DC-3 (Conversion) PT6A-67T 1400 535 November 2000 DHC-4A (Conversion)

PT6A-60 SERIES TRAINING USE ONLY INTRODUCTION XII P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface PT6 GENERAL NOTES

Initial Design ...... 1958 First Production Engine (PT6A-6, 550 SHP)... 1963 Engines Delivered...... 42338* Hours Accumulated...... 316 000 000* Certified Aircraft Applications...... 128 Different Operators ...... 6724 Different Countries ...... 171

* Numbers Current as of December 2006

The Birth Of Pratt & Whitney Canada:

In June 1927 a Wright-powered Vedette flying boat crashed in a northern Quebec lake . The RCAF purchased the seaplane from the estate of the deceased pilot and installed the engine on a Douglas seaplane . The performance of the engine led to an order for additional powerplants , with the proviso that a Canadian facility be established to service the U.S. produced engines .

PT6A-60 SERIES TRAINING USE ONLY INTRODUCTION XIII P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface MAJOR ENGINE DIFFERENCES

The PT6A Engines Covered In This Manual Are Divided equipped and connected) In 4 Groups: Group 3: PT6A-67, A-67A, A-67R, A-67AF, A-64, and - PT6A-52, 60A, 60AG, 61 A-66/A/B/D - PT6A-65B, A-65R, A-65AR, A-65AG The A-67 engines differ from the A-65 in the following - PT6A-67, A-67A, A-67AF, A-64, A-66/A/B/D manner: - PT6A-67AG, A-67B, A-67D, A-67F and A-67P - Large compressor diameter for increased mass flow - Improved compressor turbine blades design Group 1: PT6A-52, A-60A, A-60AG, and A-61 - Modified compressor turbine vane ring and shroud PT6A-52: Similar to A-61 with higher ITT at take-off segments PT6-A60A: Reference model. Derived from PT6A-42 - Redesigned power turbines with A-45 type RGB (long RGB). - Light weight magnesium inlet case instead of PT6A-60AG: Agricultural version of A-60A. Manual aluminum override system on the fuel control unit. - Light weight magnesium reduction gearbox case (long RGB). instead of aluminum for A-67 and A-67A PT6A-61: Mechanically similar to A-60 with A-41 - Reinforced reduction gearbox and bearing for A-67R type RGB (short RGB). and A-67AF) - Six engine mount pads instead of four Group 2: PT6A-65B, A-65R, A-65AR and A-65AG - Improved fuel control unit design PT6A-65R: Reference model. Similar to the PT6A-45R - Larger diameter propeller shaft flange except for increased compressor airflow - Electronic oil level indicator and pressure ratio (additional compressor - Oil tank with oil level sight glass stage). Automatic power recovery system on the fuel control unit. PT6A-67: Reference model. Derivative of A-65B with PT6A-65B: Similar to A-65R, no automatic power 10% increased flow and redesigned turbine. recovery system on the fuel control unit. PT6A-67A:Mechanically identical to the A-67 but 5% PT6A-65AR: Similar to A-65R, new fuel control unit, increase in increase cruise rating. Pusher longer compressor turbine blades for 4% application. increase in thermodynamic power. PT6A-67R:Mechanically similar to A-67A. Automatic PT6A-65AG: Hardware derivative of A-65B. Engine power recovery system on the fuel control ratings similar to A-65AR. No automatic unit. Exhaust duct rotated 30º (Shorts only). power recovery system but a manual PT6A-67AF:Derivative of A-67R with the automatic override system on the fuel control unit (if power recovery system blanked off.

PT6A-60 SERIES TRAINING USE ONLY INTRODUCTION XIV P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface MAJOR ENGINE DIFFERENCES (CONTINUED)

Group 3: (continued) Group 4: PT6A-67AG, A-67B, A-67D, A-67F and A-67P. The engines from this group include the following design PT6A-66/B: Mechanically similar to A-67 with reduction modifications for increase power ratings: gearbox capable of standard or reverse rotation (A-61 derivative, 2000 rpm). Flat - Airflow increased through fine-tuning of the rated at 850 SHP. Pusher application. compressor blade airfoil. PT6A-66D:Silimar to A-66. Single engine application. - Redesigned compressor turbines blades Flat rated to 850 shp. Manual override. - Improved cooling of the compressor turbine vane ring PT6A-64: Mechanically similar to A-66 with A-61 - Compressible seals in the hot section ("W" and "C" reduction gearbox (2000 rpm). Manual seals) override on the fuel control unit and a torque - Redesigned no. 1 bearing area limiter on the reduction gearbox. Flat rated to - Redesigned reduction gearbox to withstand higher 700 SHP. Single engine application. torque PT6A-66A: Mechanically similar to A-64 with A-64 - P3 air seal on flange "C" reduction gearbox, A-66 propeller governor - Exhaust case structurally strengthened unit and A-67AG fuel control unit (manual override). Flat rated at 850 SHP. Single PT6A-67AG: Agricultural version of the A-67R. Manual engine application. override on the fuel control unit. PT6A-67B: Mechanically similar to A-67A with increased capacity reduction gearbox. Single engine application. Manual override on fuel control unit, fixed speed propeller governor. Manual propeller overspeed governor reset/test function. Improved durability hot section. PT6A-67D: Mechanically similar to A-67B with A-67R reduction gearbox (lighter) and A-67 fuel control unit. PT6A-67F: Similar to A-67AG with higher take-off power and cruise rating. PT6A-67P: Similar to A-67B with faster climb and higher cruise speed, A-67A compressor and AGB backup generator pad.

PT6A-60 SERIES TRAINING USE ONLY INTRODUCTION XV P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface P&WC PUBLICATIONS

Pratt and Whitney Canada publish various documents and Training Manuals manuals to support all the engines in service. This is a brief description of the documents: Training guides are published by the Customer Training Centre to assist the instructors in class. Illustrated Parts Catalog (IPC) Publication Price List Contain all part numbers and parts history information along with identifying drawings for an engine series. To be The publication price list contains the prices of all P&WC used for ordering parts. publications and training material available to customers. For more information on Pratt & Whitney Canada Maintenance Manual (MM) publications contact:

The manual defines all the line and heavy maintenance Supervisor, Publications Distribution tasks that can be done on the engine as well as various 1000 Marie Victorin tests and adjustments. Longueuil, Quebec Canada J4G 1A1 Service Bulletin (SB) Telephone: 1-450-647-2705 Fax: 1-450-647-2702 Service bulletins are published to introduce new parts and E-mail: [email protected] modify existing parts to improve the product. - 13XXX series is used for the PT6A-52 / 60A / -61 / -65. -14XXX series is used for the PT6A-64 / -66 / -67.

Service Information Letter (SIL)

Service information letters are produced by Customer Support to inform all operators on new techniques, new products and other general information. They are usually valid for a 1 year period.

PT6A-60 SERIES TRAINING USE ONLY INTRODUCTION XVI P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface PUBLICATION STANDARDS

General: The engine manuals are published following the ATA 100 revision 15

The engine Maintenance Manual basic chapters and The engine illustrated parts catalogue (IPC) basic sections are: chapters and sections are:

FRONT MATTER (TEMPORARY REVISION, SERVICE 61 - 20 PROPELLER GOVERNING BULLETIN LIST) 72 - 00 ENGINE (SHIPPING) INTRODUCTION (TOOLS, CONSUMABLES) 72 - 10 REDUCTION GEARBOX AIRWORTHINESS LIMITATIONS (LIFE LIMITED PARTS) 72 - 20 AIR INLET 61 - 20 PROPELLER GOVERNING 72 - 30 COMPRESSOR SECTION 70 - 00 STANDARD PRACTICES 72 - 40 COMBUSTION SECTION 71 - 00 POWER PLANT 72 - 50 TURBINE SECTION 72 - 00 ENGINE (GENERAL) 72 - 60 ACCESSORY GEARBOX 72 - 10 REDUCTION GEARBOX 73 - 10 ENGINE FUEL and CONTROL 72 - 20 AIR INLET SECTION 73 - 20 FUEL CONTROLLING 72 - 30 COMPRESSOR SECTION 74 - 10 IGNITION 72 - 40 COMBUSTION SECTION 74 - 20 IGNITION SYSTEM 72 - 50 TURBINE SECTION 75 - 30 AIR 72 - 60 ACCESSORY GEARBOX 76 - 10 ENGINE CONTROLS 73 - 00 ENGINE FUEL AND CONTROL 77 - 20 ENGINE INDICATING SYSTEM 74 - 00 IGNITION SYSTEM 79 - 20 OIL SYSTEM 75 - 00 AIR SYSTEM 76 - 00 ENGINE CONTROLS 77 - 00 ENGINE INDICATING SYSTEM 79 - 00 OIL SYSTEM Example: A basic chapter identified as: 72-40-01 72 Indicates the engine chapter 40 Indicates the combustion section 01 Indicates the combustion chamber liner

PT6A-60 SERIES TRAINING USE ONLY INTRODUCTION XVII P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface PUBLICATION STANDARDS (CON’T)

Page blocks:

The page block numbers of each chapter are used to separate the subjects within the manual for ease of reference.

The standard page blocks are as follows:

CHAPTER APPLICABILITY Pages 61-20 70-00 71-00 72-00 All others Description and Operation 1 to 99 XXX Fault isolation 101 to 199 X Maintenance Practices 201 to 299 XX X Servicing 301 to 399 X Removal/Installation 401 to 499 XX Adjustment/Test 501 to 599 X Inspection/Check 601 to 699 XX X Cleaning/Painting 701 to 799 XX Approved Repairs 801 to 899 XX

Example: In chapter 73-10-05, page 201, you will find the maintenance practices for the fuel manifold and nozzles.

PT6A-60 SERIES TRAINING USE ONLY INTRODUCTION XVIII P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface SERVICE BULLETIN COMPLIANCE CODES

Category 1 Do before the next flight.

Category 2 Do the first time the aircraft is at a line station or maintenance base that can do the procedure.

Category 3 Do before xxx hours or xxx cycles. This Category may be expanded as required, to specify a minimum and/or a maximum and/or repetitive interval/inspection.

Category 4 Do this SB the first time the engine or module is at a maintenance base that can do the procedures, regard- less of the scheduled maintenance action or reason for engine removal.

Category 5 Do this SB when the engine is disassembled and access is available to the necessary sub-assemblies. Do all spare part assemblies.

Category 6 Do this SB when the sub-assembly is disassembled and access is available to necessary part.

Category 7 Do this SB when the supply of superseded parts is fully used.

Category 8 Do this SB if the operator thinks the change is necessary because of what he knows of the parts history.

Category 9 Spare parts information only. Old and new parts are directly interchangeable and operators can mix old and new parts.

Category 10 For information purposes only.

Category CSU Used to evaluate new parts before final introduction in commercial service. Operators who participate should include this SB at the next maintenance or overhaul of the engine.

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PT6A-60 SERIES TRAINING USE ONLY INTRODUCTION XX P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface ENGINE OVERVIEW

ENGINE OVERVIEW

PT6A-60 SERIES TRAINING USE ONLY ENGINE OVERVIEW 1.1 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface PT6A-61 RIGHT FRONT VIEW

PT6A-60 SERIES TRAINING USE ONLY ENGINE OVERVIEW 1.2 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface PT6A-64 LEFT FRONT VIEW

PT6A-60 SERIES TRAINING USE ONLY ENGINE OVERVIEW 1.3 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface PT6A-60 RIGHT FRONT VIEW

PT6A-60 SERIES TRAINING USE ONLY ENGINE OVERVIEW 1.4 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface PT6A-67 LEFT VIEW

PT6A-60 SERIES TRAINING USE ONLY ENGINE OVERVIEW 1.5 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface MAJOR ASSEMBLIES AND FLANGES

(POWER SECTION MODULE)

B C A EXHAUST DUCT

POWER TURBINE D HOUSING

POWER TURBINE SHAFT HOUSING

REDUCTION GEARBOX

BUS BAR 2ND STAGE POWER TURBINE 1ST STAGE POWER SECTION 2ND STAGE VANE RING VANE RING 1ST STAGE POWER TURBINE

PT6A-60 SERIES TRAINING USE ONLY ENGINE OVERVIEW 1.6 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface MAJOR ASSEMBLIES & FLANGES (GAS GENERATOR MODULE)

G F

DIAPHRAGM COMPRESSOR INLET ASSEMBLY CASE ACCESSORY GAS GENERATOR GEARBOX CASE COVER

COMBUSTION COMPRESSOR COMPRESSOR CHAMBER TURBINE TURBINE VANE RING GAS GENERATOR SECTION

PT6A-60 SERIES TRAINING USE ONLY ENGINE OVERVIEW 1.7 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface FEATURES

Modules: Reduction Gearbox: - Gas Generator - 2 stage planetary reduction - Power Section - Built-in hydro-mechanical torque measurement system. Main Components: - Reduce the power turbine speed to a speed suitable for propeller operation. Accessory Gearbox: - Driven by the compressor Engine Control System: - Provide drives for engine and aircraft accessories - Variable speed propeller - Reverse thrust capability Compressor: - Hydro-pneumatic fuel control unit - 3 or 4 axial stages plus 1 centrifugal impeller. - Fuel control with manual override * - Provides the necessary air mass flow at the required - Reserve power capability * pressure to sustain combustion and cool hot section - Two or Three lever power management * components. - Torque limiting device *

Combustion Chamber: * Applicable to certain models only. - Annular type - Reverse flow (shortens engine) References: - Provides an area for combustion of the air-fuel mixture Rated power...... 700 to 1650 SHP Max. air mass flow ...... 10.22 to 11.21 lbs./sec Compressor Turbine: Max. compressor P/R...... 9:1 to 12:1 - Single stage (CCW rotation) Specific fuel consumption ...... 509 to .680 LB/ESHP/hr - Recuperate power to drive the compressor

Power Turbines: - 2 stage turbine (CW rotation) - Independent from the compressor turbine (free turbine) - Extract energy to turn the propeller

PT6A-60 SERIES TRAINING USE ONLY ENGINE OVERVIEW 1.8 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface NOTES

PT6A-60 SERIES TRAINING USE ONLY ENGINE OVERVIEW 1.9 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface GENERAL TURBOPROP OPERATION

The PT6 is a lightweight turbine engine driving a propeller The hot expanding gases accelerate through the compres- via a two-stage reduction gearbox. Two major rotating sor turbine vane ring and cause the compressor turbine to assemblies compose the heart of the engine. The first is rotate (which rotates the compressor (approx. 39,000 rpm)). the compressor and the compressor turbine (compressor The expanding gases travel across the 1st and 2nd stage section) and secondly, the two power turbines and the power turbines which provides rotational energy to drive the power turbine shaft (power section). The two rotors are not propeller shaft. The reduction gearbox reduces the power connected and rotate at different speeds and in opposite turbine speed (30,000 rpm approx.) to one suitable for pro- directions. This design is referred to as a "Free Turbine peller operation (1700/2000 rpm). Engine” and has certain advantages: Gases leaving the power turbines are expelled to the atmo- - Np independent of Ng. sphere by the exhaust duct. - Lower Starter cranking torque - Modular design concept Engine shutdown is accomplished by shutting off fuel going - On-wing maintenance (Hot Section Inspection.) to the combustion chamber.

The compressor draws air into the engine via an annular An integral oil tank located in the rear section of the inlet plenum chamber (inlet case), air pressure increases across case and the accessory gearbox provides oil to bearings 3 or 4 axial stages and one centrifugal stage and is then and other various systems, such as propeller and torque directed to the combustion chamber. systems.

Air enters the combustion chamber via small holes. At the A Woodward Governor Co. fuel control unit mounted on the correct compressor speed, fuel is introduced into the com- accessory gearbox regulates fuel flow to the fuel nozzles in bustion chamber via 14 fuel nozzles. Two spark igniters response to power requirements and flight conditions. located in the combustion chamber ignite the mixture. The hot gases generated by the combustion are then directed to The propeller governor mounted on the reduction gearbox, the turbine area. controls the speed of the propeller by varying blade angle, depending on power requirements, pilot speed selection At this point, ignition is turned off since a continuous flame and flight conditions. now exists in the combustion chamber.

PT6A-60 SERIES TRAINING USE ONLY ENGINE OVERVIEW 1.10 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface TURBOPROP ENGINE

COMPRESSOR TURBINE 2 ND STAGE 1 ST STAGE ACCESSORY REDUCTION REDUCTION POWER GEARBOX GEAR GEAR TURBINES COMPRESSOR

PROPELLER SHAFT

PT6A-60 SERIES TRAINING USE ONLY ENGINE OVERVIEW 1.11 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface MAIN ENGINE BEARINGS

Function: Operation: - The ball bearings withstand the following thrusts: To support major rotating assemblies and minimize friction. - No. 1 bearing: Compressor thrust (rearward) - No. 4 bearing: Power turbine thrust (forward) Ball Bearings: - No. 6 bearing: Propeller thrust (forward) - Bearing nos. 2, 3, 5 and 7 are roller bearings Support axial and radial loads. - They support radial loading and permit axial rotor movement caused by thermal expansion Roller Bearings: - Bearings are pressure lubricated and cavities are drained by scavenge pumps Support radial load only and allows for thermal expansion. - No. 1 bearing is gravity drained

Rotating Assemblies And Their Supporting Bearings: Maintenance: - None at field level - Inspect oil filter, chip detector Propeller Shaft Power Turbine Compressor - Keep oil pressure within tolerances No 5: roller No 3: roller No 1: ball No 6: ball No 4: ball No 2: roller No 7: roller

Note: Smaller Reduction Gearboxes (PT6A-52/-60/-61/-64 and -66) do not require a No. 7 bearing.

PT6A-60 SERIES TRAINING USE ONLY ENGINE OVERVIEW 1.12 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface BEARINGS

76 5

A-60 A-65 A-67

A-52 A-61 A-64 A-66

65 4 3 21

PT6A-60 SERIES TRAINING USE ONLY ENGINE OVERVIEW 1.13 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface STATIONS

7 6 5 4 3 2.5 2 1

1 - AIR INTAKE 2 - COMPRESSOR INLET 2.5 - COMPRESSOR INTERSTAGE 3 - COMPRESSOR DISCHARGE PRESSURE 4 - COMPRESSOR TURBINE INLET 5 - INTERTURBINE 6 - TURBINE EXHAUST 7 - EXHAUST OUTLET

PT6A-60 SERIES TRAINING USE ONLY ENGINE OVERVIEW 1.14 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface STATIONS

TEMP PRESS PSIA 1100

1000 150 900 140 130 800 120 700 110 600 100

500 90 80 400 70 60 300 50 40 200 30 20 100 10 0

2 P2.5 P3 T4 T5 6

NOTE: 1 PRESSURES AND TEMPERATURES LISTED ARE TAKEN AT TAKEOFF POWER, STANDARD TEMPERATURE7 DAY FOR A PT6A-65 ENGINE PRESSURE

PT6A-60 SERIES TRAINING USE ONLY ENGINE OVERVIEW 1.15 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface ENGINE EXTERNAL COMPONENTS

1. Reversing Cable 2. T5 Harness 3. T1 Trim Resistor (Trim Stick) 4. Decal Patents Designation 5. Cam Box (Reversing) 6. Oil Return From Airframe Cooler 7. Overboard Breather Discharge 8. Oil Dipstick - (Electrical A-67B) 9. Starter/Generator Pad 10. Fuel Control Unit 11. Oil To Airframe Cooler 12. Fuel Pump 13. Oil To Fuel Heater 14. Oil Pressure Tapping 15. P3 Air Filter 16. Oil Filter Cover 17. P3 Air Delivery Tube To Fuel Control Unit 18. Bleed Valve 19. Main Oil Pressure Line 20. Propeller Tach-Generator Pad 21. Data Plate Gas-Generator (Engine) 22. Plate Instructions, Gas Generator

PT6A-60 SERIES TRAINING USE ONLY ENGINE OVERVIEW 1.16 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface EXTERNAL COMPONENTS

1 3 2 5 4 6

8 7

18 21 17

22 16

11 15

12 14 13

PT6A-60 SERIES TRAINING USE ONLY ENGINE OVERVIEW 1.17 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface ENGINE EXTERNAL COMPONENTS

1. Inlet Screen 2. P2.5 Cabin Bleed 3. Fireseal - Front 4. Fuel Nozzle Adapter 5. Py Air Line 6. Data Plate - Power Section 7. Propeller Governor (CSU) 8. Propeller Shaft 9. Propeller Overspeed Governor Pad 10. Torque Oil Pressure Port 11. Chip Detector 12. Igniter Plug 13. Engine Mount Pad 14. P3 Cabin Bleed Port 15. Oil Scavenge Tubes 16. Ignition Cables 17. Exciter Box 18. Wash Spray Ring 19. Oil Level Sightglass 20. Rear Fireseal 21. Oil From Airframe Cooler

PT6A-60 SERIES TRAINING USE ONLY ENGINE OVERVIEW 1.18 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface EXTERNAL COMPONENTS

5 3 7 2 4 1 6 21

8 20

16 14 10 15 9 13 12 11

PT6A-60 SERIES TRAINING USE ONLY ENGINE OVERVIEW 1.19 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface BLANK PAGE

PT6A-60 SERIES TRAINING USE ONLY ENGINE OVERVIEW 1.20 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface COMPRESSOR SECTION

COMPRESSOR SECTION

PT6A-60 SERIES TRAINING USE ONLY COMPRESSOR SECTION 2.1 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface COMPRESSOR SECTION

Function: Compressor Air Is Used For The Following: - Supplies the required mass of air at the right pressure - Sustain combustion in order to produce the energy to the combustion chamber and all the supporting sys- required to drive the compressor and the power sec- tems tion (propeller) - Transmits the rotational energy from the compressor - Provide cooling air for hot section components turbine to drive the accessories mounted on the acces- - Provide air to seal bearing cavities sory gearbox - Assist in the operation of the fuel control unit - Controls bleed valve operation - Provides heating and pressurization for cabin use Subjects Covered: - De-ice various airframe components - Inertial separator (airframe) - Inlet case - Compressor assembly - Bleed valve - Pre-swirl system (jet flap piccolo inlet) - Gas generator case - Cold section cleaning

Operation:

The compressor draws air into the engine and compresses it before delivery to the combustion chamber area.

PT6A-60 SERIES TRAINING USE ONLY COMPRESSOR SECTION 2.2 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface COMPRESSOR SECTION

BLEED VALVE

COMPRESSOR INLET CASE

GAS GENERATOR

PT6A-60 SERIES TRAINING USE ONLY COMPRESSOR SECTION 2.3 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface INERTIAL SEPARATOR (AIRFRAME)

Function:

Protects the engine from ingesting foreign objects such as When carrying-out a performance check, always assure stones, ice, sand, snow, rain, etc. that the inertial separator doors are in the CLOSED position. Inertial separator doors left in the open position will cause an increase in Ng, ITT and Wf which could be Operation: interpreted as a deteriorated compressor.

Deployment of the inertial separator to the bypass (icing) position forces air in the nacelle to execute a sharp turn before entering the engine. Water droplets, ice crystals or snow, because of their inertia, tend to maintain their original high velocity path and are discharged overboard through the separator bypass duct.

Note: The inertial separator is an airframe-supplied item. Not using the inertial separator in icing conditions could result in costly damage to the compressor blades. Ensure separator operates freely. Erratic movement of the separator vane may cause engine parameter fluctuation. For specific maintenance action, refer to the Airframe Maintenance Manual.

PT6A-60 SERIES TRAINING USE ONLY COMPRESSOR SECTION 2.4 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface INERTIAL SEPARATOR (TYPICAL)

BYPASS (ICING) POSITION

NORMAL POSITION

PT6A-60 SERIES TRAINING USE ONLY COMPRESSOR SECTION 2.5 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface COMPRESSOR INLET CASE

Function: Maintenance: - Directs air into the compressor - Inspect inlet screen for damage and cleanliness. Wire - Support no. 1 bearing mesh damage is not acceptable - Forms the oil tank - Inspect inlet screen rubber sealing rims for damage - Piccolo holes in hollow struts generate pre-swirl - Inspect inlet case for cracks in the strut area - Sight glass on left side of case allows for quick oil level - Cracks are not acceptable on Inlet Case check (not on A-60/61/65) - Inlet screen (1/4 inch mesh) prevents objects from entering the compressor

Construction: - One piece magnesium casting - External surfaces painted with epoxy paint

Operation:

The annular configuration of the PT6 inlet case facilitates the protection against Foreign Object Damage (FOD). Because the compressor rotor intake is not in line with the flight path, the incoming air makes a sharp turn before entering the inlet case. This configuration is combined with the inertial separator for maximum protection against FOD.

Piccolo holes in the inlet case strut change the direction of incoming air at the face of the compressor rotor. Inlet case strut anti-icing is provided by heat conduction from the oil contained in the tank.

PT6A-60 SERIES TRAINING USE ONLY COMPRESSOR SECTION 2.6 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface INLET CASE

FORWARD

OIL TANK VENT AND PRESSURIZING VALVE OIL RETURN FROM COOLER PICOLLO HOLES OIL TO AGB

OIL FILTER INLET SCREEN HOUSING LOCATION AIR INLET OIL FROM OIL LEVEL SIGHT GLASS THERMOSTATIC AND BYPASS VALVE

NO.1 BEARING OIL TANK SCAVENGE OIL TANK NO.2DRAIN BEARING SCAVENGE RETURN

PT6A-60 SERIES TRAINING USE ONLY COMPRESSOR SECTION 2.7 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface COMPRESSOR

Function: Compression Ratios: - Provides the combustion chamber with the correct airflow at the required pressure 52, 60A,61 9.0 - The number 1 bearing supports the rear end of the compressor 64, 65, 66, 67 12.1 - The flexible housing transforms compressor vibrations Operation: Construction: Axial stage accelerates the air, which is then decelerated A-52/60/61: through divergent stator vanes, thus increasing the air pres- - Three axial rotors and a centrifugal impeller sure. The same process is repeated throughout all the com- - Early engines used assembly of disks and blades for pressor stages. all 3 axial stages The dynamic pressure (air velocity) generated by the cen- - SB 13093, introduces integral bladed rotor (IBR) on trifugal impeller speed is transformed into static pressure by 1st. stage only the diffuser pipes divergent shape which reduces the air speed and increases the compressor discharge pressure A-65’s: (P3). - Four axial (blade & hub) rotors and a centrifugal impel- Nos. 1 and 2 bearings support the compressor rotor. The ler. IBR root forms the inner gas path profile; the stator vanes - SB 13017 Introduces 1st stage IBR. form the outer gas path wall. - SB 13140 Introduces 4 stages of IBR’s. The no. 1 bearing is supported by the compressor inlet case via a flexible housing. Compressor unbalance caused A-64. 66 & 67: by normal engine wear produces vibrations that are trans- - Four IBR type axial rotors and a centrifugal impeller formed by the number 1 bearing flexible housing, reducing vibrations transmitted to the engine mounts and aircraft. Stator vanes are mounted after each axial rotor. Rotating components are made of titanium and are held in place with Maintenance: tie rods that extend through the compressor stages. - Check first stage blades for FOD every time the inlet Maximum compressor speed 39,000 rpm (104%). screen is removed - Blending is recommended to prevent cracks from developing on the leading edge of the blades - Refer to the Engine Maintenance Manual for acceptable blade damage and blending limits - Do compressor Wash at regular intervals

PT6A-60 SERIES TRAINING USE ONLY COMPRESSOR SECTION 2.8 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface COMPRESSOR

BLEED AXIAL VALVE STAGES NO. 2 BRG. CENTRIFUGAL PICCOLO IMPELLER HOLES NO. 1 BRG. NO. 1 BRG. FLEXIBLE HOUSING

GAS GENERATOR INLET CASE CASE

PT6A-60 SERIES TRAINING USE ONLY COMPRESSOR SECTION 2.9 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface COMPRESSOR WASH

Function: - Remove salt and dirt deposits from the compressor After Wash Procedure: gas path - Reconnect P3 line to the FCU - Promote parts life and reduce potential overhaul costs Special Procedure: - If isopropyl alcohol or kerosene was used in the Type Of Washes: cleaning solution perform a dry motoring run before - Desalination wash starting the engine to avoid a hot start. - Performance recovery wash - Ref. M/M 71-00-00 Desalination Wash: - Recommended when operating in a salt laden atmosphere Method: - Use drinking water with low mineral content - Motoring wash - De-mineralized water is recommended - Refer to the Engine Maintenance Manual for washing mixtures preparation and procedures Performance Recovery Wash: - Recommended every 100 - 200 hr based on the flying environment Prior To Washing, Make Sure That: - Water based detergents are used to remove stubborn - 40 minutes minimum cooling period dirt deposits which cannot be removed using water - P3 line going to the FCU is removed* only - Cabin bleed is off - Solution is injected into the compressor using the - No power extraction wash ring mounted over the inlet screen - Follow starter limitations - At OAT below 2 °C (36 °F), isopropyl alcohol must be - Ensure removal of exhaust duct drain plug if installed added to the water to prevent freezing * Not applicable if post SB 13175/14054 (P3 filter bowl drain valve) - Allow 15-20 minute soaking period - Perform two rinse cycles (water)

PT6A-60 SERIES TRAINING USE ONLY COMPRESSOR SECTION 2.10 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface COMPRESSOR WASH

COMPRESSOR WASH RING

SHUTOFF CLEANING SHUTOFF VALVE SOLUTION VALVE PRESS. PRESS. GAGE GAGE

REGULATED SPRAY SPRAY AIR PRESSUREWATER RING RING REGULATED AIR PRESSURE WATER

DESALINATION SYSTEM PERFORMANCE RECOVERY SYSTEM

PT6A-60 SERIES TRAINING USE ONLY COMPRESSOR SECTION 2.11 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface COMPRESSOR BLEED VALVE (64/65/66/67)

Function: Px pressure depends on the restriction at the outlet of the cavity where it is drawn. This restriction is controlled by the Prevents compressor stall at low Ng. inside diameter of the compressor turbine stator air seal (baffle). SB14117 introduces a classified stator air seal on Construction: certain engine models to improve control of Px pressure. - Non-flowing type Some late A-65 models also incorporate a classified stator - A piston slides on a guide pin inside a housing air seal. ( SB 13108 & SB 13311 ) - Seal rings on the piston minimize Px leak - A classified seat controls the closing point (Ng) of the The surface area on which P2.5 pushes depends on the bleed valve inside diameter of the bleed valve classified seat. Different classes of seats are available for bleed valve closing point Operation: adjustment.

Two forces act on the bleed valve piston. Px air pressure pushes to close the bleed valve and P2.5 air pressure, from Maintenance: the inter-stage compressor area, pushes to open it. Px is - Check for evidence of air losses at sealing faces and derived from P3 air. P3 passes through a restriction when it mating surface flows between the no. 2 bearing housing and the no. 2 bear- - Check valve seat/piston for damage ing cover. At low power setting, Px is lower than P2.5 keep- - Check free movement of piston ing the bleed valve open. In this position, P2.5 air is directed - Bleed valve closing point into the plenum chamber and into the inlet case struts. - Retain classified seat when replacing bleed valve

When the compressor speed increases, Px rises faster than P2.5, thus increasing the pressure acting on top of the pis- The piston can fall out of the BOV assembly ton to gradually close it. The speed (Ng) at which the valve closes is a function of 2 variables. One is the Px pressure when the classified seat is removed and the second is the surface area on which P2.5 air pressure is pushing on the piston.

PT6A-60 SERIES TRAINING USE ONLY COMPRESSOR SECTION 2.12 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface COMPRESSOR BLEED VALVE (64/65/66/67)

DETAILA SEAL RING

RETAINING GUIDE PIN RING

BLEED VALVE A COVER PX PX PISTON SEAL RING VALVE SEAT RETAINING RING

SEAL RING BLEED VALVE CLASSIFIED HOUSING VALVE SEAT

PX (P3) PISTON P2.5

PT6A-60 SERIES TRAINING USE ONLY COMPRESSOR SECTION 2.13 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface COMPRESSOR BLEED VALVE (52/60/61)

Function: As Ng increases, P3 rises faster than P2.5, thus increasing the pressure acting on the piston to gradually close it. The Prevents compressor stall at low Ng speed (Ng) at which the valve closes is a function of the Pri- mary and Convergent Divergent orifice sizes. A larger Pri- Description: mary orifice requires less Ng speed (less P3 pressure) to close the valve. Pressure operated piston sliding on a guide pin. Piston discharges P2.5 to atmosphere at low Ng. speed. A rolling Maintenance: diaphragm mounted on the valve piston prevents leakage - Check for air losses at sealing faces and mating sur- between P2.5 and the Px chamber. faces - Check that piston moves freely Construction: - Check seat or piston for damage - Flowing type - Pressure check - A piston slides on a guide pin inside a housing - Clean orifices - A flexible diaphragm seals the piston - Calibrated orifices control the valve closing point (Ng) Pressure Check:

Operation: To verify the integrity of the Bleed Valve diaphragm

Two forces act on the bleed valve piston. Modified P3 air Description: (Px) pressure pushes to close the valve and P2.5 air pres- - Remove Bleed valve spring pin sure, from the inter-stage compressor area, pushes to open - Seal valve seat on a rubber sheet and secure in posi- it. tion - Remove two plugs on Bleed valves and install appro- P3 air flows through a primary metering orifice and is priate equipment as per M/M directed to the top of the piston and to atmosphere via a - Apply required pressure to valve and check that leak- convergent divergent orifice. The bleed valve closing point age is within limits occurs, during engine acceleration, when the pressure acting on the valve diaphragm (Px) is sufficient to overcome the compressor inter-stage pressure (P2.5).

PT6A-60 SERIES TRAINING USE ONLY COMPRESSOR SECTION 2.14 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface BLEED VALVE (52/60/61)

CONTROL PRESSURE (Px) AMBIENT PRESSURE (Pa) COVER FINAL ROLLING DIAPHRAGM ORIFICE GUIDE PIN SHAFT

PISTON PRIMARY Px Px ORIFICE PISTON DAMPER DISCHARGE (SPRING LOADED) TO ATMOSPHERE DELIVERY AIR PASSAGE P3 SLEEVE PISTON SEAT

P3 P2.5

P2.5

CLOSED POSITION OPEN POSITION

PT6A-60 SERIES TRAINING USE ONLY COMPRESSOR SECTION 2.15 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface PRE-SWIRL SYSTEM

Function: Operation: - Change the relative angle of attack of the air entering the compressor When the bleed valve opens, P2.5 air flows to the plenum - Improve surge margin at low compressor speed chamber and to the inlet case hollow struts. The piccolo holes located on the inlet case struts produce P2.5 air jets Description: that cause swirling of the incoming air before it enters the - Hollow inlet case struts with holes compressor. The swirl is turning in the same direction of - Piccolo holes on most A-64/67 the compressor, which makes it easier to draw in air thus - Slotted holes combined with swing check valve and increase compressor performance at low Ng. orifice A-52/60/61, A65AG,AR - Bleed valve Swing Check Valve: - Bleed valve plenum chamber Pre-SB13016 A-65 engines use an orifice and a swing check valve to relieve excess P2.5 air pressure when the compressor bleed valve opens. The swing check valve is on the left-hand side of the gas generator on A-65's, or on top of the bleed valve for A-52/60/61's. The swing check valve prevents air from entering the plenum chamber at high power after the bleed valve has closed. Inlet case with Pic- colo holes can handle all the airflow without a swing check valve.

Maintenance: - Check for proper operation of the bleed valve - Proper installation/sealing of the bleed valve

PT6A-60 SERIES TRAINING USE ONLY COMPRESSOR SECTION 2.16 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface PRE-SWIRL SYSTEM (PICCOLO HOLES)

INLET SCREEN

INLET AIR

P 2.5 INTERSTAGE AIR

PICCOLO HOLES

NO. 1 BEARING

PT6A-60 SERIES TRAINING USE ONLY COMPRESSOR SECTION 2.17 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface NOTES

PT6A-60 SERIES TRAINING USE ONLY COMPRESSOR SECTION 2.18 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface PRE-SWIRL SYSTEM (52/60/61) (SLOTTED STRUTS)

CASE HOLLOW STRUT TANGENTIAL FLOW (JET FLAP)

SWING INLET SCREEN CHECK VALVE AIR INLET

P 2.5 INTER-STAGE AIR

COMPRESSOR A65’s BLEED VALVE BLEED AIR CASE ASSEMBLY FIRST - STAGE P 2.5 COMPRESSOR BLADE P 2.5

P 2.5 NO. 1 BRG. (REF)

GAS SWING CHECK GENERATOR VALVE CASE

A52/60/61

PT6A-60 SERIES TRAINING USE ONLY COMPRESSOR SECTION 2.19 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface BLEED VALVE CLOSING POINT (65/67)

Function: Note: If closing point does not fall within the tolerance band, the To verify at what Ng speed the bleed valve closes. following adjustments can be made.

- Install higher class seat to raise Ng closing point Description: - Install lower class seat to lower Ng closing point - Replace bleed valve if piston does not move freely Use the pressure pick-up port located on the P2.5 cabin bleed adapter. Bleed Valve Closing Point (64/66):

Operation: There is no closing point test for these models. - The pick-up tube connects to a flexible hose in a con- tainer filled with water - Bubbles form when the bleed valve opens - Stabilize engine at ground idle - Increase Ng until bubbles stop forming - Record Ng speed (closing point) - Ensure closing point falls within tolerance band on MM graph

PT6A-60 SERIES TRAINING USE ONLY COMPRESSOR SECTION 2.20 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface BLEED VALVE CLOSING POINT CHECK

37.5

95.1

NOTE: OPERATING ABOVE THE BAND 94 IS ACCEPTABLE.

90 PRESSURE − ZERO OR NO BUBBLES

PLENUM 88

85.55 RUBBER TUBE 86

GAS GENERATOR SPEED (Ng) % GAS GENERATOR SPEED 84.25 NOTE: OPERATING BELOW THE BAND IS NOT RECOMMENDED, AS THIS MAY RESULT IN ENGINE STALL / SURGE DURING ACCELERATION / DECELERATION. 84

82 −30 −20 −10 0 10 20 30 40

OUTSIDE AIR TEMPERATUREo ( C)

BUBBLER WATER

PT6A-60 SERIES TRAINING USE ONLY COMPRESSOR SECTION 2.21 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface BLEED VALVE CLOSING POINT (52/60A/61)

Description: Closing Point Too HIGH (Ng) ->Install Larger Orifice:

A different closing point test is required for these BOV’s because these engines are ‘flat rated’ so they can make If plotted point is above acceptable range with more power at higher altitudes and temperatures. For this existing class of metering plug, and falls reason the BOV is open under most circumstances at low below acceptable range with next higher class altitude and temperature (on the ground). from existing plug, the Final Orifice (convergent/divergent) must be enlarged. The closing point is extrapolated in reference to a running Refer to M/M section 71-00-00 Adjustment/ condition taken as follows: Test - Remove P2.5 transfer tube from bleed air case and install adapter using suitable flexible tube. Connect to a digital pressure gauge. - Record Tam in degree °C, and Pam in In. Hg. - Start engine, let Ng stabilize at ground idle. - Slowly increase power until plenum pressure (PP) peaks, then starts falling. - Continue to accelerate engine to max. allowable power Ref. M/M. 71-00-00. - Let engine stabilize for 2 minutes, record Ng and PP - Shut down engine. - Calculate normalized Gas Generator speed and normalized plenum pressure as per M/M. 71-00-00 (Adjustment/Test) to determine the closing point as per the chart in the MM. - If closing point is above or below acceptable range replace the primary metering plug with next higher or lower class as required.

PT6A-60 SERIES TRAINING USE ONLY COMPRESSOR SECTION 2.22 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface BLEED VALVE CLOSING POINT CHECK (52/60/61)

CABIN BLEED AIR TRANSFER TUBE BOSS

DIGITAL PRESSURE GAGE

PT6A-60 SERIES TRAINING USE ONLY COMPRESSOR SECTION 2.23 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface GAS GENERATOR CASE

Function: Operation:

Houses and supports various engine components such as The gas generator case houses the components necessary #2 brg, compressor assembly, engine mounts, diffuser for the compression of air and combustion of the fuel/air pipes. mixture. The gas generator case contains P3 air pressure.

The diffuser pipes change the high velocity (2000ft/sec) low Tubes for oil pressure and scavenge to the number 2 bear- pressure into low velocity (200ft/sec) and high pressure. ing as well as tapping for P3 air for the operation of the They also turn the air flow 90° to direct the air to the Com- bleed valve and fuel control unit are provided inside the gas bustion Chamber. generator case.

Description: Two P3 operated drain valves located at the six o'clock posi- - Welded assembly of steel alloy machined parts and tion ensures fuel does not remain in the case after engine sheet metal shutdown. - Diffused aluminized coating - 21 brazed diffuser pipes Maintenance: - Support for the compressor stator parts - Inspect for cracks and signs of P3 leaks. - Support for the no. 2 bearing - Inspect engine mount threaded holes. - 14 bosses for fuel nozzles - Inspect diffuser pipes for cracks etc. - 2 bosses for igniter plugs - 2 bosses for drain valves Note: - 1 boss for P3 air (to FCU) The A67B & D models have studs instead of bolts to secure - 1 P2.5 bleed port the nozzles - 2 P3 bleed port (A-60/61/65 one) - Provision for 6 engine mounts (A-60/61/65 four)

PT6A-60 SERIES TRAINING USE ONLY COMPRESSOR SECTION 2.24 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface GAS GENERATOR CASE / DIFFUSER

AIR PRESSURE TUBE TO BLEED VALVE DIFFUSER PIPE FLANGE "C"

NO. 2 BEARING. PRESSURE OIL TUBE

P3 PRESSURE TUBE NO. 2 BEARING TO FUEL CONTROL SCAVENGE OIL TUBE

STRAIGHTENING VANE

PT6A-60 SERIES TRAINING USE ONLY COMPRESSOR SECTION 2.25 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface COLD SECTION TROUBLESHOOTING

Problem Symptoms At Constant Power Action Required Ng T5 Wf Restricted inlet screen up up up Clean and/or remove obstruction Dirty compressor up up up Perform compressor wash /revise schedule Damaged compressor blades up up up Blend blades as per Engine Maintenance Manual. Return to an approved overhaul facility if damage is beyond limit. Bleed valve stuck open or clos- up up up Ensure P3 is not leaking between ing at too high Ng bleed valve and gas generator case. Replace bleed valve. P3 leaks same up up Check for external leaks on gas generator. Verify sealing surfaces in Hot section at next HSI. Check engine bleed system. Excessive loading of starter gen- down up up Replace faulty starter erator or other AGB mounted accessories. Bleed valve closes too soon Compressor stalls during acceleration at altitude Replace faulty BOV. Re-check closing point. Bleed valve stuck closed Compressor stalls Replace bleed valve

Note: Generally, compressor section problems cause Ng, T5 and Wf to increase. However, the above list of possible problems includes some that will make the engine react differently.

PT6A-60 SERIES TRAINING USE ONLY COMPRESSOR SECTION 2.26 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface COMBUSTION & TURBINE

COMBUSTION & TURBINE

PT6A-60 SERIES TRAINING USE ONLY COMBUSTION & TURBINE 3.1 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface HOT SECTION

Description:

Produce and extract energy from the hot expanding gases to drive the compressor turbine, compressor and AGB accessories. At the same time, drive the power turbines / propeller to provide thrust for the aircraft.

Components: - Combustion chamber - Compressor turbine vane ring - Compressor turbine - Power turbine housing - Power turbine vane rings - Power turbines - Exhaust duct

Operation:

The hot section of the engine is comprised of components down stream of the compressor. Hot expanding gases leaving the combustion chamber are directed towards the compressor turbine blades by the compressor turbine vane ring and drive the compressor. Gases then travel across the 1st stage power turbine vane ring and drive the 1st stage power turbine (and again across the 2nd stages).

Turbine rotation is transmitted to the propeller via the power turbine shaft and the reduction gearbox. Gases leaving the power turbine are expelled to the atmosphere through the exhaust duct. The exhaust gases add some ‘jet thrust’ as a result of the airframe exhaust stubs.

PT6A-60 SERIES TRAINING USE ONLY COMBUSTION & TURBINE 3.2 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface HOT SECTION AREA

POWER TURBINE POWER POWER STATOR HOUSING EXHAUST TURBINES TURBINE CASE VANE RINGS

NO. 2 BRG COMBUSTION COMPRESSOR COVER CHAMBER TURBINE FLANGE VANE RING

SHROUD LOCK SEALING SHROUD SEGMENTS PLATE RING SEGMENT COMPRESSOR HOUSING TURBINE

SMALL EXIT DUCT NO. 2 BRG C.T. BAFFLE COVER

PT6A-60 SERIES TRAINING USE ONLY COMBUSTION & TURBINE 3.3 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface COMBUSTION CHAMBER LINER & SMALL EXIT DUCT

Function: The combustion chamber forms an envelope that turns the gas 180°. This configuration permits location of the tur- Provide an area for the combustion of fuel/air mixture and bines closer to the compressor and within the combustion form an envelope that changes the direction of the gas flow chamber area, thus making the engine shorter and lighter. 180°. Cooling rings direct P3 air into the combustion chamber, close to the walls, to form a flame barrier.

Construction: Maintenance: - Annular, reverse flow type combustion chamber - Replace the liners as a set. - Made of nickel alloy (Inconel) sheet metal - Check the cooling ring gaps as per MM. - Ceramic coating on inner walls create a thermal bar- - Inspect for cracks, burning, buckling repair as per MM. rier - 14 fuel nozzle bosses - 2 spark igniter bosses Troubleshooting: - Cooling rings protect the combustion chamber walls from the flame Intermittent puffs of black smoke indicate carbon build-up in the C.C. The fix is to incorporate a liner with more cooling holes (SB13177/14055) or replace the existing liners with a Operation: TDF* liner (SB 14048).

P3 air enters the combustion chamber through holes in the * Thermal Distribution Factor inner and outer liners. The shape, size and location of these holes provide the correct fuel/air ratio for all operating conditions.

PT6A-60 SERIES TRAINING USE ONLY COMBUSTION & TURBINE 3.4 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface COMBUSTION CHAMBER AND SMALL EXIT DUCT

FUEL NOZZLE COOLING RINGS ADAPTER BOSSES

LOUVERED COOLING RING

OUTER LINER

INNER LINER SMALL INNER LINER SPARK EXIT IGNITER BOSS DUCT SMALL EXIT DUCT COOLING RING

PT6A-60 SERIES TRAINING USE ONLY COMBUSTION & TURBINE 3.5 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface COMPRESSOR TURBINE VANE RING

Vane Ring: Operation: - Directs and accelerates gases to the compressor turbine at the optimum angle and speed. The compressor turbine vane ring receives hot gases from - Convergent vanes change static pressure into velocity the combustion chamber. The vane airfoil arrangement - The lug to slot fit determines the radial location of the converges the air towards the exit, accelerating and chang- shroud housing and is important for tip clearance con- ing its direction simultaneously. trol Vane ring classes determine the sum of the area in square Effect Of Vane Area (Class) On T5 And Ng At Constant inches, of all the openings between the vane trailing edges. Power: At assembly, the proper class of vane is selected to ensure that NG and T5 will be within specified limits. A lower vane ring class (smaller area) accelerates the air therefore Increase Area Ng ↓ T5 ↑ increases the speed of the compressor turbine and compressor (Ng). A higher Ng speed provides more air to the Decrease Area Ng ↑ T5 ↓ engine, increasing cooling and lowering T5.

Shroud Housing: The compressor turbine vane ring is subject to very high - Supports shroud segments and inter-stage sealing temperatures. Vane airfoils are cooled with P3 air. After ring cooling, air is ejected in the gas path at the vane trailing - Slots in the shroud housing match with corresponding edge. lugs on the vane ring to prevent shroud housing rotation Shroud segments come in different classes (thickness) to fit different compressor turbine diameters this maintains the Shroud Segments: gap between the compressor turbine blades and the seg- - Correct class selection and grinding of shroud segments (tip clearance) within specified limits. ments provide adequate blade tip clearance and minimize gas leakage. (10 or 20 segments) Replacement: - Thickness is classified to fit different compressor turbine outside diameter Replace with same area as original or within ±0.03 sq.in. of the original class from the last test. (Ref. SIL PT6A-032)

PT6A-60 SERIES TRAINING USE ONLY COMBUSTION & TURBINE 3.6 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface COMPRESSOR TURBINE VANE RING (52/60/61)

COMPRESSIBLE SEALS INTERSTAGE (SB13168) SEAL RINGS P3 AIR SMALL EXIT DUCT

VANE OUTER RING LINER

SHROUD TIP HOUSING CLEARANCE

LOCK PLATE P3 AIR SHROUD SEGMENT P3

NO.2 BEARING COVER COMPRESSOR TURBINE P3

P3 POST-SB 13181

PRE-SB 13181

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(64, 66, 67A, AG, AF, R) SHROUD HOUSING INTERSTAGE SEALING RINGS

P3 AIR SMALL EXIT DUCT

VANE RING

TIP P3 AIR SHROUD CLEARANCE SEGMENTS

COMPRESSOR P3 TURBINE LOCK PLATE

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(66B, 66D, 67B, 67D, 67F and 67P)

COMPRESSIBLE SEALS

SMALL INTERSTAGE EXIT SEALING RINGS DUCT

P3 AIR P3 AIR VANE RING SEAL RING

TIP CLEARANCE

P3 AIR

P3 AIR COMPRESSOR TURBINE

P3 AIR

LOCK PLATE

NO.2 BEARING COVER

PT6A-60 SERIES TRAINING USE ONLY COMBUSTION & TURBINE 3.9 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface COMPRESSOR TURBINE

Function: At maximum speed, the compressor rotor turns at approximately 39,000 rpm (104%), with each blade pulling on the Extract energy from the hot gases to turn the compressor disk with a force of approximately one ton (2000 lbs.). rotor unit. The turbine is individually balanced on two planes with detail weights. This feature allows for turbine replacement in Description: the field. The PT6A-64/66/67 has detail weights plus trim - Turbine disk is machined from a nickel alloy. weights to match the disk to the compressor rotor. - Blades are cast of a nickel-based alloy and coated with a sacrificial coating for protection against sulphidation. - Fir-tree serration’s support turbine blades and allow for thermal expansion differences between the blades Engine Type # Of Blades and the disk - Rivets lock the blades onto the disk A52/60/61/65 59 - A master spline on the disk ensures reinstallation of A64 pre SB14118 52 the compressor turbine in its initial position A66/67R,A,AF pre SB14061 - PT6A-64/67 blade tip is hollow (pocketed), to reduce weight and centrifugal pull A64 post SB14118 43 A66/67R,A,AF post SB 14061 A66B/D, A67B, D, F, P Operation:

Expanding gases, accelerated through the vane ring hit the turbine blades. The energy available in the gases is con- verted into rotational movement to drive the compressor and the engine accessories. Nearly two thirds of all the energy available from the products of combustion is needed to drive the compressor and the accessories. The remaining one third is used to drive the power turbines.

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MASTER SPLINE

DETAIL WEIGHT

CUP WASHER

RETAINING BOLT

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(64, 66, 67)

Function: Example:

A residual unbalance remains once the CT is mated with 1st weight -- B 05 L -- the compressor assembly. Adding TRIM weights minimizes vibration and maintains original compressor rotor balance B Denotes trim weight class (A,B, C, D, E and G) during field replacement of the compressor turbine. 05 Number from 01 to 40 denotes position of first rivet retaining trim weight from number 1 in direction of J arrow. Description: L Denotes weight offset in relation to first hole occu- - Detail Balancing (PWC approved facilities only) pied by weight retaining rivet from number 1 in direc- - Initial balancing of the compressor turbine using detail tion of arrow. weights on the two balancing planes - Trim Balancing -H Heavy offset - After initial detail balancing, the compressor turbine is -L Light offset re-balanced with the compressor assembly using - N No offset (weight symmetrical) trim weights on the same two balancing planes.

Note: - The data plate indicate the location of the trim weights - Trim weights are always installed in pairs facing one another on the two balancing planes. - Detail weights are installed by approved facilities only - Trim weights can be installed by the operator - An Overhaul Shop or Service Center can install the trim weights when requested by the operator

PT6A-60 SERIES TRAINING USE ONLY COMBUSTION & TURBINE 3.12 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface COMPRESSOR TURBINE

TRIM BALANCE WEIGHTS

#1 ALIGNED WITH 1 2 C/T DISK REAR FACE PLANE B PLANE A 3 4 MASTER SPLINE 5 6 7 8 FRONT REAR FACE 9 FACE 10

C/T DISK FRONT FACE

MANUFACTURED HEADS LIGHT ON INSIDE OF RIM, BOTH FACES 2 1 OFFSET 4 3 5 HEAVY 6 OFFSET 7 8 9 10

DATA PLATE

PERFORMANCE REFERENCE DATA NG SHP NUMBER FROM 01 TO 40 DENOTES POSITION OF 35050 √θ AT 1137 δ√θ FIRST RIVET RETAINING TRIM WEIGHT FROM O ITT TRIM 90.2 23 OHMS THIRD NUMBER 1 IN DIRECTION OF ARROW. COMPRESSOR TURBINE TRIMC WEIGHTS WEIGHT

B 05 L B 08 H G 10 N N/R G 10 N ENG. BUILD SPEC. T.C. DENOTES WEIGHT OFFSET H. HEAVY OFFSET IN RELATION TO FIRST L. LIGHT OFFSET DENOTES TRIM WEIGHT CLASS HOLE OCCUPIED BY WEIGHT N. NO OFFSET RETAINING RIVET FROM (WEIGHT SYMMETRICAL) A CLASS 1 C CLASS 3 E CLASS 5 NUMBER 1 IN DIRECTION OF ARROW B CLASS 2 D CLASS 4 G NO WEIGHT, RIVET ONLY

A B C CL1 CL2 CL3

D E G CL4 CL5

PT6A-60 SERIES TRAINING USE ONLY COMBUSTION & TURBINE 3.13 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface ALTERNATE TRIM WEIGHTS (64/66/67)

Function: Starting from hole no. 4 counter clockwise and from hole no. 7 clockwise (the weights are installed at holes no. 39 Allows the trim balancing to perform even when the trim and 40 on one side and holes no. 11 and 12 in the other). weights location as per the data plate is occupied by detail Alternatively, 2 class # 1 weights can be installed 6 holes balancing weights. away or 2 class # 4 weights can be installed 8 holes away.

For cases where class 2 or class 4 weights must be Description: installed as alternate trim weights; try to maintain symmetry by installing one weight with a light offset and the other with A table in the maintenance manual provides a choice of a heavy offset. alternative location to install the trim weights away from the position marked on the reference data plate when this position is occupied by detail balancing weights. The trim weight is replaced by a pair of weights that are installed on each side and equidistant from original trim weight location (ref. data plate)

Example:

On the turbine illustrated below there is a detail weight at the positions 5 and 6 so the trim weight B 05 L marked on the data plate cannot be installed (interference at hole no. 5). According to the table, we can replace a “B” type weight (class 2) by installing two class # 1 (‘A’) weights, 5 holes away on each side of the detail weight.

PT6A-60 SERIES TRAINING USE ONLY COMBUSTION & TURBINE 3.14 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface ALTERNATE TRIM WEIGHTS

NOTE: WHEN A NEW DETAIL WEIGHT OCCUPIES A TRIM WEIGHT ORIGINAL LOCATION (REF. DATA PLATE), ALTERNATIVE TRIM WEIGHTS MUST BE USED IN PAIRS TRIM WEIGHT TABLE ONE EACH SIDE OF AND EQUIDISTANT FROM ORIGINAL TRIM WEIGHT LOCATION (REF. DATA PLATE).

TRIM WEIGHT CLASS FROM DATA PLATE A B C D E G CLASS CLASS CLASS CLASS CLASS SINGLE 11 2 3 4 5 RIVET

2 CL1

3 CL1 NUMBER OF HOLES 40 2 CL1 39 3 ORIGINAL POSITIONEACH SIDEOF TRIM OF 4 38 1 4 WEIGHT (REF. DATAORIGINAL PLATE), TRIM WEIGHT LOCATION 5 CL1 CL2 37 5 NOW OCCUPIED BY NEW CL1 36 6 DETAIL WEIGHT. CL1 CL2 5 6 C/T DISK35 ASSEMBLY HOLES 7 BALANCING CL17 CL1 CL2 CL3 RIM34 8 CL3 CL4 CL5 SINGLE CL18 RIVET 33 9 CL3 CL4 32 5 10 HOLES 11

12 13

ALTERNATIVE TRIM WEIGHT LOCATION DETERMINED USING TRIM WEIGHT TABLE DATA PLATE

PERFORMANCE REFERENCE DATA CT DISK ASSEMBLY TRIM WEIGHTS NG SHP 35050 √θ AT 1137 δ√θ ITT TRIM 90.2 O 23 OHMS COMPRESSOR TURBINE TRIMC WEIGHTS

B 05 L B 08 H G 10 N N/R

ENG. BUILD SPEC. T.C.

PT6A-60 SERIES TRAINING USE ONLY COMBUSTION & TURBINE 3.15 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface POWER TURBINE VANE RINGS

Function: Operation: - Direct gases to the first and second stage power turbines at the optimum speed and angle Gases leaving the compressor turbine are accelerated - Change static pressure into velocity through the first and second stage vane rings while causing their respective power turbines to rotate. First Stage: - Riveted centre baffle directs air for cooling onto the The first and second stage vane rings are held in place by Compressor turbine disk and the power turbines. lugs fitted in the power turbine housing. The riveted inner - Exit area of the vane ring is classified. baffle directs air close to the power and compressor turbine - Keep with the Gas Generator as a matched set. disks for cooling. The selection of different vane areas allows for optimization of Ng vs. T5 during engine test. Second Stage: - Inner section supports an abradable seal. The second stage vane ring supports an abradable seal - Both vane rings are supported by the Power Turbine that diverts cooling air to the two adjacent faces of the Housing. power turbines. - A lug to slot arrangement centralizes and prevents rotation of the two vane rings. - Not classified Replacement:

Replace within ±0.1 sq.in. of the original area from the last Effect Of Vane Ring Class Change At Constant Power: test. (Ref. SIL PT6A-032)

Increase area Ng ↑ T5 ↓

Decrease area Ng ↓ T5 ↑

PT6A-60 SERIES TRAINING USE ONLY COMBUSTION & TURBINE 3.16 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface POWER TURBINE VANE RINGS

P.T. VANE RING T5 PROBE FIRST STAGE SLOT

P.T. VANE RING SECOND STAGE

AIRFLOW

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Function: Operation:

Extract energy from the gases to drive the propeller through The two power turbines extract the energy necessary to the reduction gearbox. drive the propeller.

The rotational energy extracted by the power turbine is Description: transmitted to the power turbine shaft through splines on - Turbine disks are machined from nickel alloy the second stage turbine hub. - Coupled together by a lug to slot arrangement - Fir-tree serration’s in the disks support the blades and Removal of the power turbines is permissible at field level to allow for thermal expansion differences between the replace the second stage vane ring. Balancing of the power disk and the blades turbines is done with the power turbine shaft and the num- - Rivets lock the blades in place ber 3 and 4 bearings, this is the reason why power turbines - 2nd stage turbine attaches to the power turbine shaft are not field replaceable. via splines - Power turbine blades are shrouded at the tip to form a solid rim around blade tips and reduce blade vibration Maintenance: - To allow for thinner, more efficient airfoil that offsets - Inspect the 2nd stage PT blades for cracks. SB 14172 the weight penalty of the shrouded blade tips - Pre SB every 1500 hrs. - To reduce gas leakage at the tip of the blade - Post SB every 4000 hrs. - No shroud segments, a double knife edge provides sealing at the blade tip

References:

Max Nf A-52/60/61...... 30400 rpm Max Nf A-64...... 30144 rpm Max Nf A-66...... 30400 rpm Max Nf A-65/67...... 29930 rpm

PT6A-60 SERIES TRAINING USE ONLY COMBUSTION & TURBINE 3.18 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface POWER TURBINES

FIRST STAGE POWER TURBINE SHROUDED BLADES

AIR SEAL

SECOND STAGE POWER TURBINE

PT6A-60 SERIES TRAINING USE ONLY COMBUSTION & TURBINE 3.19 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface TURBINE WASH

Function: Sulphidation:

Remove salt deposits from the turbine section of the engine Sulphidation is a common name for a type of hot corrosion to minimize sulphidation of the turbine blades. which can affect turbine area components.

Sulphidation occurs at engine operating temperatures when Method: sodium and sulphur are present. All turbine fuels contain sulphur in sufficient amounts for this chemical reaction to Motoring wash with turbine wash nozzle inserted in igniter occur. Common sources of sodium are seawater, atmo- port. PT6A-67B/D/F/P’s have a dedicated wash port. spheric pollutants and volcanic discharge.

Sulphidation attacks the CT blades, but it is not uncommon Description: for the CT stator and other non-rotating components to be affected. It can not be detected by performance run data The washing medium used is drinkable water. It is recom- analysis. mended that this procedure be carried out when operating in a salt laden atmosphere. It is also recommended to per- Stage 1: Initial coating deterioration. Slight roughen- form the turbine wash in conjunction with compressor wash. ing of the surface caused by some growth and break- It is essential that the compressor section be washed first down of the oxide layer. Mechanical integrity is not (refer to compressor section in this manual). affected. Water is injected into the turbine section using a turbine Stage 2: Initial corrosion. Surface roughness is more wash nozzle through one igniter port. Ensure that the arrow marked as oxide layer breakdown continues. Mechani- sign on the tool tang is pointing towards the reduction gear- cal integrity is not affected. box. Stage 3: Advanced corrosion. Oxidation of the base material has penetrated to significant depth, with obvi- The procedure to perform the turbine wash is identical to ous build-up scale. Mechanical integrity seriously the compressor desalination wash. Refer to the Engine affected. Progression to Stage 4 will accelerate. Maintenance Manual chapter 71 for more details. Stage 4: Severe corrosion. Deep penetration, large blisters are apparent. Failure is likely due to loss of structural material.

PT6A-60 SERIES TRAINING USE ONLY COMBUSTION & TURBINE 3.20 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface TURBINE WASH

SHUTOFF VALVE 34 CLEAN OR DEMINERALIZED WATER

PRESSURE GAGE

REGULATED AIR / NITROGEN PRESSURE

PT6A-60 SERIES TRAINING USE ONLY COMBUSTION & TURBINE 3.21 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface EXHAUST DUCT & PT SHAFT HOUSING

Exhaust Duct: - Direct the exhaust gases to ambient atmosphere with minimum flow restriction - Welded assembly of heat resistant Nickel alloy sheet metal - On the A-67R/A-65AR, the exhaust duct is rotated 30° to suit the airframe installation (Shorts)

Power Turbine Stator Housing: - Support the power turbine vane rings, the T5 harness and thermocouples - Interfaces with the gas generator section via a seal ring

Insulation Blanket: - Minimizes heat transfer between the hot gases and the reduction gearbox and the power turbine shaft housing

Power Turbine Shaft Housing: - Support the power turbine shaft - Forms a cavity for bearing no. 3 and 4

Power Turbine Shaft: - Supported by bearing no. 3 and 4 - Transmits power turbine speed and torque to the reduction gearbox via the power turbine shaft coupling and the reduction gearbox first stage sun gear

PT6A-60 SERIES TRAINING USE ONLY COMBUSTION & TURBINE 3.22 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface EXHAUST DUCT & PT SHAFT HOUSING

POWER NO. 3 BEARING PT SHAFT TURBINE SHAFT HOUSING POWER TURBINES POWER TURBINE STATOR HOUSING PT SHAFT HOUSING

POWER TURBINE RGB INSULATION NO. 4 VANE RINGS REAR BLANKET BEARING CASE EXHAUST DUCT FLANGE "B"

PT6A-60 SERIES TRAINING USE ONLY COMBUSTION & TURBINE 3.23 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface SEALING OF THE HOT SECTION AREA

(52/60/61/64/65/66/67, A, AF, R)

Function:

Gas sealing in the hot section area is a very important factor affecting hot section life. This section describes the major sealing surfaces in the hot section and their purposes.

Sealing Description Function Face A Vane ring to small exit duct and shroud housing Prevent P3 air around the combustion chamber to leak and bypass the vane ring B Lock plate to vane ring Prevent P3 leaks from combustion chamber area to other side of vane ring C Power turbine housing to shroud housing seal Prevent P3 leaks into P5 D First stage PT vane to second stage PT vane Prevent leaks around the second stage vane ring

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B A D C

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(67AG, 67B, D, F, P, T, 66B, 66D)

Function:

Gas sealing in the hot section area is a very important factor affecting hot section life. This section highlight sealing surfaces in the hot section and their functions.

Sealing Description Function Face A Lock plate to vane ring Prevent P3 leaks between combustion chamber and no. 2 bearing cover area. B Small exit duct to shroud housing Prevent P3 leaks between combustion chamber and vane ring top section. C&D Vane ring to shroud housing Forms a chamber for vane ring cooling air. E Power turbine housing to shroud housing seal Prevent P3 leaks into P5 ring F First stage Power turbine vane to second stage Prevent leaks around the second stage vane ring. PT vane

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FEDCB A

PT6A-60 SERIES TRAINING USE ONLY COMBUSTION & TURBINE 3.27 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface HOT SECTION TROUBLESHOOTING

Problem Symptoms At Constant Power Action Required Ng T5 Wf Seal ring leak Same Up Up Reposition or replace seal ring. Verify seal ring groove and replace shroud housing if damaged. Gas leakage at junction between Same Up Up Lap sealing faces. Send parts to an small exit duct and vane ring approved shop if required to restore the sealing faces. Replace compressible seals (certain models only) Burnt CT vane ring (larger throat area) Down Up Up Replace vane ring High compressor turbine tip clearance Down Up Up Replace shroud segments to restore clearance. Send turbine to overhaul facility for reblading if necessary. Eroded compressor turbine blades Down Up Up Send assembly to an approved facility for blade replacement.

NOTE: Hot section problems are all characterized by high T5 and Wf. Ng usually goes down or remains constant.

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GEARBOXES

PT6A-60 SERIES TRAINING USE ONLY REDUCTION GEARBOX 4.1 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface REDUCTION GEARBOX

Function: The second stage reduction system is similar to the first stage but uses five planet gears instead of three. The sec- Reduce the power turbine speed to a speed suitable for pro- ond stage gear carrier drives the propeller shaft via splines. peller operation. Reverse rotation on the A-66 is achieved by securing the second stage carrier to the front reduction gear case and Construction: allowing the second stage ring gear to rotate. - Two stage planetary reduction system - Magnesium front and rear housing A bevel gear on the propeller shaft provides drive for 3 RGB mounted accessories: Reduction Ratios: 1. Propeller Governor (CSU) 2. Propeller Overspeed Governor (A/F) 60A/65/67 A-52/A61/64/66 3. Np Tacho Generator

1St Stage 5.78:1 5.33:1 Maintenance: - Verify chip detector for metal contamination. 2nd Stage 3.04:1 2.83:1 - Verify reduction gearbox scavenge strainer for metal contamination. Overall ratio 17.58:1 15.10:1 - Replace propeller shaft oil seal if leak is evident. Max. Np (rpm) 1700 2000 - Replace Np Tach-Gen lip seal on RGB accessory drives - Touch-up scratches on prop shaft. Operation: - CSU & OSG gaskets - Field repairs are not allowed inside the reduction gear- The PT6 engines use a planetary type reduction gearbox box. system with two stages of reduction. The first stage consists of a sun gear meshing with three planet gears mounted in a carrier. The three planet gears mesh on the outside with a ring gear splined into the reduction gearbox casing. The first stage gear carrier drives the second stage sun gear through a flexible coupling arrangement. Provi- sion to measure torque is provided by the first stage reduction system.

PT6A-60 SERIES TRAINING USE ONLY REDUCTION GEARBOX 4.2 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface REDUCTION GEARBOX

REAR HOUSING 1ST STAGE 2ND STAGE

FRONT HOUSING

PT6A-60 SERIES TRAINING USE ONLY REDUCTION GEARBOX 4.3 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface STANDARD ROTATION REDUCTION GEARBOX

SECOND STAGE SECOND STAGE PLANET GEAR RING GEAR FIRST STAGE RING GEAR ACC. DRIVES(3) FIRST STAGE PLANET GEAR

FIRST STAGE SUN GEAR SECOND STAGE SUN GEAR

PT6A-60 SERIES TRAINING USE ONLY REDUCTION GEARBOX 4.4 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface PT6A-66 REVERSE ROTATION GEARBOX

PT6A-60 SERIES TRAINING USE ONLY REDUCTION GEARBOX 4.5 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface ACCESSORY GEARBOX

Function: Construction: - Two light alloy casings (diaphragm and rear hsg.) sup- Provides drive pads for engine and airframe accessories port the drive gears. such as: - The casings are bolted together and then to the inlet - Fuel pump and fuel control unit case. - Starter-generator - The front casing (diaphragm) separates and seals the - Oil pressure and scavenge pumps accessory gearbox from the oil tank - Ng tacho-generator - Optional aircraft accessories - Centrifugal breather impeller to separate air from oil in Maintenance: the accessory gearbox - On condition - Replace accessory drive seals - Replace air/oil separator carbon seal Forms a housing and supports the following: - Replace starter drive gear - Oil filler neck - Inspect AGB scavenge pump inlet screen - Electric/standard dipstick - Oil filter and housing assembly - Oil pressure pump - Oil pressure regulating valve - Cold oil pressure relief valve

PT6A-60 SERIES TRAINING USE ONLY REDUCTION GEARBOX 4.6 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface ACCESSORY GEARBOX

FUEL PUMP & FCU GEAR CENTRIFUGAL BREATHER & STARTER GENERATORS GEARS

6250 RPM

11000 RPM

OPTIONAL ACCESSORY DRIVES 7650 PRE-SB14112 MAIN OIL PRESSURE PUMP,RPM OIL SCAVENGE PUMP & 4200 TACHO-GENERATOR RPM

EXTERNAL OIL SCAVENGE & POST-SB14112 OPTIONAL DRIVE

12000 RPM

3800 RPM

PT6A-60 SERIES TRAINING USE ONLY REDUCTION GEARBOX 4.7 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface PIN LOCK ARRANGEMENT

COMPRESSOR HUB PIN A.G.B. COUPLING SHAFT

INSERT

SEAL RINGSPRING SLEEVE

PT6A-60 SERIES TRAINING USE ONLY REDUCTION GEARBOX 4.8 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface ACCESSORY GEARBOX

BALL-LOCK ARRANGEMENT PRE SB13161

ACCESSORY GEARBOX HOUSING FLANGED ROLLER BEARING ACCESSORY GEARBOX DIAPHRAGM BALL LOCK

REAR HUB COMPRESSOR ASSEMBLY

PLUG

OIL TRANSFER TUBE

GEARBOX INPUT DRIVESHAFT

INLET CASE PRESSURE PUMP

PT6A-60 SERIES TRAINING USE ONLY REDUCTION GEARBOX 4.9 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface NOTES

PT6A-60 SERIES TRAINING USE ONLY REDUCTION GEARBOX 4.10 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface OIL SYSTEM

OIL SYSTEM

PT6A-60 SERIES TRAINING USE ONLY OIL SYSTEM 5.1 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface OIL SYSTEM

Function: Oil System Flushing: - Supplies filtered oil to the engine in order to cool, lubri- - Flush oil system if new type of oil is to be used cate and clean various components - Refer to Engine Maintenance Manual for flushing pro- - Provides oil to the propeller governor to allow propeller cedure pitch and speed control. - Changing from Type II to Type II Third Generation oil - Provides oil to the torque measurement system can only be done with new or newly overhauled engines Description: The engine oil system consists of a pressure system, a Oil Temperature Limits (Typical): scavenge system and a breather system. The PT6 lubrication system provides a constant supply of clean oil to the Starting:...... - 40° C min engine bearings, reduction gears, accessory drives, Take off:...... 0° C - 110° C torquemeter and propeller governor. The oil tank is inte- Recommend oil temp: ...... 74° C - 80° C grated in the engine air inlet casing. The oil lubricates and cools bearings and carries any extraneous matter to the oil Note: filter where it is precluded from further circulation. A chip Refer to engine Maintenance Manual for specific limits. detector is located on the reduction gearbox to detect metal particles and warn operators of metal contamination. Max Oil Consumption: - 0.3 lb/hr oil consumption Servicing: - measured over a 10 hour period - Use approved synthetic oil listed in SB 13001 and - (3 lb/10 hr.) (2 lb/10 hr. for A-52/60/61/66) 14001. - Check oil level within 15-20 minutes after shut down. - If more than 30 minutes have elapsed before checking References: oil level, and dipstick shows oil is needed, run engine prior to adding oil. 3 lbs ...... 1.5 U.S. qt - Oil changes required as specified by the Airframe Oil tank capacity...... 2.5 U.S. gal maintenance manual. Oil tank expansion space ...... 0.7 U.S. gal - Ensure that oil pressure is within limits (approx. 90-135 Oil tank usable quantity...... 1.5 U.S. gal PSIG). Check with NG above 72%.

PT6A-60 SERIES TRAINING USE ONLY OIL SYSTEM 5.2 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface OIL SYSTEM (BOTTOM VIEW)

OIL TO AIRFRAME COOLER OIL PRESSURE LINE

OIL OUT TO COOLER

NO. 2 BEARING RGB & PROPELLER

NO. 3 & 4 BEARING SCAVENGE PRESSURE

PT6A-60 SERIES TRAINING USE ONLY OIL SYSTEM 5.3 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface OIL SYSTEM

Pressure System: The accessory gearbox receives oil from the No. 1, 2, 3 and 4 bearings scavenge systems. From there, the oil is routed Oil is drawn from the oil tank through a gear type pump and to the fuel heater by the AGB scavenge pump. is delivered to the oil filter and Pressure Regulating Valve. At the filter outlet, pressure oil separates into several paths. From the outlet of the fuel heater, the oil is directed to the thermostatic bypass valve. Depending on the oil tempera- The no. 1 bearing and accessory input drive shaft are lubri- ture, the thermostatic bypass valve directs the oil to either cated with oil directed through cored passages and transfer the oil tank or the airframe oil cooler. tubes. The oil pressure transmitter and the oil temperature bulb are mounted on ports located on this internal passage. The oil coming back from the airframe oil cooler gets back to the tank through an anti-splashing adapter at the top of A single tube located at the bottom right hand side of the the tank. engine, delivers oil to lubricate the no. 2, 3 and 4 bearings, the reduction gearbox, front accessories and then to the propeller and torque measurement systems.

Scavenge System:

The scavenge system consist of four gear type pumps assembled in two double elements. Two pumps are located inside the accessory gearbox while the other two are mounted externally at the rear of the accessory gearbox.

No. 1 bearing scavenges into the accessory gearbox by gravity. No. 2 bearing scavenge through a tube mounted underneath the engine. At high power a relief valve mounted on the line near the scavenge pumps allows air/oil from the bearing cavity to bleed into the accessory gearbox, preventing flooding of the number 2 bearing cavity.

PT6A-60 SERIES TRAINING USE ONLY OIL SYSTEM 5.4 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface OIL SYSTEM (REAR) FUEL HEATER

OIL IN FROM AIRFRAME COOLER

THERMOSTATIC BYPASS & CHECK VALVE

CENTRIFUGAL TO OIL BREATHER AIRFRAME COOLER

MAIN OIL FILTER

C P P OIL PRE R

R PUMP V V

PRESSURE TRANSMITTER S .

TEMP. BULB

TANK DRAIN

SCAVENGE OIL

OIL SUPPLY TO PROPELLER & REDUCTION

PT6A-60 SERIES TRAINING USE ONLY OIL SYSTEM 5.5 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface OIL SYSTEM (CONT’D)

No. 3 and 4 bearing area scavenge into the accessory gearbox via a scavenge tube mounted on the left-hand side of the engine. Oil is scavenged by one of the externally mounted pumps located at the rear of the accessory gearbox.

The reduction gearbox and the propeller oil system are scavenged through an external tube located beside the No. 3 and 4 bearing scavenge tube. The oil is pumped by the second externally mounted scavenge pump and goes directly to the airframe oil cooler.

Note: The PT6A- 64/66/67/67A/AF/AG/B/D/F/P/R scavenge system differs from the other engines. The No. 2 bearing scavenge pump sends oil directly to the fuel heater and diverter valve instead of sending it to the accessory gearbox. (post SB 14108)

PT6A-60 SERIES TRAINING USE ONLY OIL SYSTEM 5.6 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface OIL SYSTEM (FRONT)

TORQUE PRESS. TRANSDUCER

PROPELLER GOVERNOR

OIL SUPPLY TO PROPELLER

TORQUEMETER

OIL SUPPLY SCAVENGE OIL TO PROPELLER AND REDUCTION

PT6A-60 SERIES TRAINING USE ONLY OIL SYSTEM 5.7 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface OIL PRESSURE REGULATION & FILTRATION

Oil Pump: Filter: - Gear type - 15 micron filter with 40 micron internal screen. - Inlet screen protects the pump - Clean electro-sonically only (post SB 13412 and 14392 are not cleanable). - Inspect every 100 hours. Pressure Regulating Valve: - Discard at 1000 hours - Maintains engine oil pressure within specified limits (90 - 135 PSI) (100 - 135 PSI for PT6A-52/60/61/64 /66). Filter Bypass Valve: - When oil pressure increases above the spring tension, - Bypasses oil if the oil filter becomes restricted the valve moves up, opening a passage to the inlet of - Valve opens when pressure inside the oil filter is 24 psi the pump, thereby limiting the oil pressure lower than the pump pressure - Allows oil to flow through the secondary filter and to engine lubrication system Cold Oil Pressure Relief Valve: - At this point, indicated oil pressure is lower than nor- - Controls excessive pressure build up during cold mal (24 psid) weather starting - When the pressure regulating valve is fully open and oil pressure keeps increasing, the cold oil valve opens Maintenance: to dump more oil back to the pump - Service oil tank - The relief valve opens at 160 psid - Check chip detector for presence of metal - Maintain oil pressure within limits - Inspect and clean oil filter Filter Check Valve: - Replace oil filter at 1000 hr - Opens at a 15 psid to allow oil flow to the filter. - Replace oil if operated above max oil temperature - Prevents static oil transfer from the oil tank to the pres- - Min oil pressure @IDLE : 60 psi sure system and AGB. - Inspection of the oil filter without draining the oil tank

PT6A-60 SERIES TRAINING USE ONLY OIL SYSTEM 5.8 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface OIL PRESSURE REGULATION & FILTRATION

PRESSURE REGULATING VALVE COLD OIL PRESSURE RELIEF VALVE BLEED ORIFICE

FILTER SECONDARY FILTER BYPASS VALVE

INLET CASE REF

OIL PUMP FILTER `O`RING CHECK HOUSING VALVE OIL PUMP GEARS

PRESSURE OIL TO PRESSURE INLET SYSTEM SCREEN

OIL BY PASS OIL

FILTERED PRESSURE OIL

PT6A-60 SERIES TRAINING USE ONLY OIL SYSTEM 5.9 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface THERMOSTATIC BYPASS & CHECK VALVE

Function: The check valve opens when the oil pressure coming from the fuel heater is higher than the pressure of the scavenge Bring oil to normal operating temperature faster during first oil from the reduction gearbox by 5 psi. This allows the oil few minutes of engine operation. from the fuel heater to mix with the reduction gearbox scavenge oil and go to the airframe before it returns to the tank.

Description: If the bypass valve fails to open at low oil temperatures then - Mounted on the inlet case oil pressure will build up and force the check valve to open. - Consists of a housing, a thermostatic valve and a check valve If the check valve can not open, the relief spring of the thermostatic bypass valve bypasses oil from the fuel heater to the tank, even if the expansive material is fully expanded, to Operation: prevent over pressurization and over loading of the accessory gearbox scavenge pump. A pressure of 40 to 55 PSID Oil coming out from the fuel heater is directed to the ther- is necessary to overcome the relief spring. mostatic bypass and check valve. The thermostatic element contracts when the oil is cold. This allows the oil to return to the tank instead of going to the airframe oil cooler. Maintenance: Thermal element can be replaced in the field if defective. The check valve prevents back flow of the scavenge oil from Check valve may be lapped in the field. the reduction gearbox to the tank through the thermostatic bypass valve. As the oil warms-up, the thermostatic element expands to gradually close the bypass valve. It begins Troubleshooting: to close when the oil temperature reaches approximately - Oil taking too long to reach normal operating tempera- 60° C and is fully closed around 72° C. As the bypass valve ture may be caused by faulty thermostatic element closes, the oil is forced towards the check valve. - Oil temperature higher than normal may be caused by faulty thermostatic valve and/or check valve stuck closed.

PT6A-60 SERIES TRAINING USE ONLY OIL SYSTEM 5.10 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface THERMOSTATIC BYPASS & CHECK VALVE

THERMOSTATIC EXPANSIVE ELEMENT MATERIAL RETURN FROM COOLER OIL OUT AGB TO TANK BYPASS RETURN VALVE SPRING OIL TANK OIL FROM AGB SCAVENGE FCU

RELIEF SPRING FUEL OUT

CHECK OIL OUT TO VALVE AIR FRAME COOLER THERMOSTATIC FUEL IN FUEL HEATER BYPASS

OUT TO COOLER RGB SCAVENGE

SCAVENGE OIL AIR & OIL MIST AIRCRAFT BOOST FUEL PRESSURE

PT6A-60 SERIES TRAINING USE ONLY OIL SYSTEM 5.11 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface OIL SYSTEM TROUBLESHOOTING

Symptoms Possible Cause And Fix High Oil Pressure Check indicating system Adjust/verify pressure regulating valve. Low Oil Pressure Clean/replace oil filter Check indicating system Cracked oil pump housing Adjust pressure regulating valve Oil Pressure Fluctuation Check oil level Check indicating system Check oil tank pressurizing valve Replace/Clean pressure regulating valve High Oil Temperature Check oil temperature indicating system Check airframe oil cooler Check thermostatic bypass and check valve Check scavenge pump inlet for blocage

PT6A-60 SERIES TRAINING USE ONLY OIL SYSTEM 5.12 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface OIL SYSTEM TROUBLESHOOTING (CONT’D))

Symptoms Possible Cause And Fix Excessive Oil Discharged From Oil level kept too high. Overboard Breather Verify oil filter check valve (static transfer, blown out during start). Check O-rings between oil filter housing and inlet case (static transfer) Verify/replace centrifugal breather carbon seal in accessory gearbox. Check pressure pump drive seal (static transfer blown out during start). Check AGB scavenge pump screen for blockage (flooding of AGB). Excessive Oil Consumption All of the above. Check for oil external leaks. Ensure oil is not transferring into AGB & leaking out of Inlet/BOV. Check for traces of oil in the exhaust (#3 brg. lab. seal leaking). Check oil to fuel heater for internal leakage. Oil Leak From Intake Check O-ring and Teflon® ring on oil filter housing. (Oil Transfer To AGB) Check oil filter check valve for leakage. Main oil pump lip seal. Check for broken O-rings in AGB. Oil Pressure Follows Power Lever Check Main Oil Pump Housing for correct assembly torque or cracks.

PT6A-60 SERIES TRAINING USE ONLY OIL SYSTEM 5.13 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface NOTES

PT6A-60 SERIES TRAINING USE ONLY OIL SYSTEM 5.14 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface SECONDARY AIR SYSTEM

SECONDARY AIR SYSTEM

PT6A-60 SERIES TRAINING USE ONLY ENGINE INDICATING 6.1 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface SECONDARY AIR SYSTEM

General:

The secondary air system consists of all the compressor air that is not used to sustain combustion or for airframe use.

Of all the air entering the engine the combustion process uses only 25%, 65% cools the combustion gases, the airframe uses 5% and the secondary air system uses the remaining 5%.

The Secondary Air System Provides Pressure Air For: - Cooling of hot section parts - Sealing of bearing compartment - Operates bleed valve and pre-swirl (jet flap) - Operates fuel purge valve - Operates fuel control unit (P3 Filter)

Two sources of air used in the secondary air system:

P2.5 Compressor Inter-stage air pressure P3 Compressor delivery pressure

This Section Is Divided Into 4 Parts: 1. Accessory gearbox breather 2. Oil tank pressurizing valve 3. Turbine cooling 4. Bearing compartment sealing

PT6A-60 SERIES TRAINING USE ONLY ENGINE INDICATING 6.2 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface SECONDARY AIR SYSTEM

P2.5 P2.5 P3 P3

PT6A-60 SERIES TRAINING USE ONLY ENGINE INDICATING 6.3 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface ACCESSORY GEARBOX BREATHER

Function: The relatively oil free breather air flows through the center of the impeller and out to the atmosphere via a cored pas- Separates oil particles from air in the accessory gearbox sage in the accessory gearbox diaphragm. before discharging overboard.

Maintenance: Description: - On condition - Centrifugal impeller - Replace carbon seal - Mounted on the starter generator gear shaft - Starter generator gearshaft front end is sealed with a Blocked Or Restricted Breather Hose May: carbon face seal - Cause loss of oil through No. 1, 2 and 3 bearing cavities - Cause oil leak at flange "G" Operation: - Cause accessory drive seals to leak - Increase oil consumption Oil and air scavenged from the bearing cavities are directed - Cause an oil smell in the cabin to the accessory gearbox. The air/oil combination in the accessory gearbox causes foaming of the oil. The continuous flow of scavenged air and oil causes the accessory gearbox to pressurize. Prior to venting the air to the atmosphere, the oil must be separated from the air.

The pressure builds up in the accessory gearbox forces the air/oil mixture inside the breather impeller. The centrifugal force imparted by the impeller causes the heavier oil particles to be ejected back into the accessory gearbox.

PT6A-60 SERIES TRAINING USE ONLY ENGINE INDICATING 6.4 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface ACCESSORY GEARBOX BREATHER

STARTER / GENERATOR GEAR

CARRIER CARBON SEAL

BREATHER IMPELLER

CARBON SEAL BREATHER IMPELLER CARRIER

CARBON SEAL

AIR AIR / OIL MIX

PT6A-60 SERIES TRAINING USE ONLY ENGINE INDICATING 6.5 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface OIL TANK PRESSURIZING VALVE

Function: The oil tank pressurizing valve maintains air pressure in the tank 5 to 7 psi above the accessory gearbox pressure. This Reduces oil pressure fluctuation and oil consumption at positive pressure applied on the oil reduces pressure fluctu- high altitude. ation and oil consumption at altitude.

When static pressure in the tank reaches the specified limit, Description: the piston compresses the spring, allowing oil tank air pres- - Valve seat and spring loaded piston sure to flow into the accessory gearbox. From the acces- - Located in the inlet case (oil tank) at the 11 o'clock sory gearbox, air flows through the centrifugal impeller and position out to the atmosphere. - Maintains the oil tank pressure 5 to 7 psi above accessory gearbox pressure Troubleshooting:

Operation: Oil loss through overboard breather tube or the pressurizing valve being stuck open may cause oil pressure fluctuation During normal operation, oil scavenge system collects air at altitude. and oil from various bearing cavities. The accessory gearbox breather removes most of the air contained in the oil but some air remains trapped in the oil. Maintenance: - On condition When air and oil are carried from the cooler to the tank, it - Remove and inspect valve causes oil in the tank to foam. Foaming may cause cavita- - Ensure freedom of movement tion of the pressure pump and fluctuation of oil pressure at - Lap piston and seat high altitude.

As altitude increases, air pressure in the tank drops and causes air trapped in the oil to expand (foam) and fill the tank completely. At this point, the excess foam transfers to the accessory gearbox thus causing an increase in oil loss through the centrifugal breather.

PT6A-60 SERIES TRAINING USE ONLY ENGINE INDICATING 6.6 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface OIL TANK PRESSURIZING VALVE

PRESSURIZING VALVE HOUSING SEAT INLET CASE

AGB DIAPHRAGM PISTON

AIR / OIL MIX

AIR

OIL

PT6A-60 SERIES TRAINING USE ONLY ENGINE INDICATING 6.7 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface TURBINE COOLING AND AIRBLEED SYSTEM

Description:

Internal passages in the engine distribute P3 air to provide cooling to the combustion chamber turbine and vane rings. After cooling, the air is evacuated in the gas path.

Using the same distribution passages, P2.5 and P3 air are provided to the no. 1, 2 and 3 bearing labyrinth seals. Air flows into the bearing compartments is evacuated via the oil scavenge system and discharged overboard through the centrifugal breather impeller located in the accessory gearbox.

Tapping on the gas generator case provides P2.5 and/or P3 air for external systems such as cabin environmental control system, de-icing system, door sealing, etc...

Maintenance And Troubleshooting: - Keep P3 and P2.5 leaks to a minimum - (performance losses) - Ensure cooling rings in the combustion chamber are in satisfactory condition - Ensure no leak exists on airframe air bleed system

PT6A-60 SERIES TRAINING USE ONLY ENGINE INDICATING 6.8 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface TURBINE COOLING AND AIRBLEED SYSTEM

P2.5 P3

PT6A-60 SERIES TRAINING USE ONLY ENGINE INDICATING 6.9 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface BEARING COMPARTMENT SEALING

Function: Possible Cause For Oil Loss Through Labyrinth Seals: - Lack of air flow through labyrinth seal (Not probable) Prevents oil from leaking outside the bearing cavities. - Wear on the knife's edges due to rotor unbalance or bearing distress Description: - Oil coking in the grooves between the knife's edges - Labyrinth seals - Flooding of bearing cavity due to malfunction in the oil - Consists of a multi-grooved ring running within a scavenge system (most probable) straight stator ring - Air pressure fills the air gap between the two parts Problem Area Symptom Operation: No. 1 Bearing Oil smell in cabin Oily bleed valve and compressor The air seal consists of two separate parts, one stationary and one rotating. One of the two parts has machined No. 2 Bearing Oil smell in cabin grooves. A small clearance is maintained between the two (Rear) parts and air pressure is blowing between them creating a No. 2 Bearing Coking around no. 2 high velocity air flow that draws the oil towards the inside of (Front) bearing and compressor turbine the bearing cavity. area Possible smoke on start and shutdown Maintenance: - None No. 3 Bearing Possible smoke on start and shut- - During HSI, ensure holes in the number 2 bearing down area of gas Generator are not blocked Oil in exhaust duct - Keep accessory gearbox breather outlet free of obstruction - Do not over service the oil tank

PT6A-60 SERIES TRAINING USE ONLY ENGINE INDICATING 6.10 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface BEARING COMPARTMENT SEALING

P2.5 P3 P3

NO.3 BEARING NO.2 BEARING NO.1 BEARING

PT6A-60 SERIES TRAINING USE ONLY ENGINE INDICATING 6.11 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface NOTES

PT6A-60 SERIES TRAINING USE ONLY ENGINE INDICATING 6.12 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface ENGINE INDICATING SYSTEM

ENGINE INDICATING SYSTEM

PT6A-60 SERIES TRAINING USE ONLY ENGINE INDICATING SYSTEM 7.1 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface ENGINE INDICATING SYSTEM

Function: - Provide the pilot with indications concerning the engine parameters during flight - Provide the required data for engine condition trend monitoring and performance

Engine Indicating Systems: - Ng / Np Tachometer-Generators (Pulse pick-up probes on the PC12) - Oil temp/ Oil pressure indication - Chip detector

Indicating Systems Built Into Engines: - Inter turbine temperature system (T5) - Torque indication system

PT6A-60 SERIES TRAINING USE ONLY ENGINE INDICATING SYSTEM 7.2 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface ENGINE INDICATING SYSTEM

COMPRESSOR SPEED OIL TEMPERATURE (C˚) ITT TORQUE PROPELLER SPEED NG (%) AND PRESSURE (PSIG) (C˚) (FT-LBS) Np (RPM)

OIL 9 0 21 8 20 1 14 20 11 12 45 50 20 0 7 3 2 START 40 0 6 5 4 % 3 10 15 9 ITT TORQUE PROP RPM 11 RPM 35 5 6 10 8 ˚c x 100 FTLB 15 10 4 X 1005 2 5 7 2 30 x10010 X 100 5 9 6 6 3 25 8 7 -2 PSI0 5 4 20 15 10 0 x 10

Np TACHO GENERATOR

Ng TACHO GENERATOR OIL PRESSURE TRANSMITER PORT OIL TEMPERATURE BULB

PT6A-60 SERIES TRAINING USE ONLY ENGINE INDICATING SYSTEM 7.3 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface INTER-TURBINE TEMPERATURE (T5)

Function:

Provides an indication of the Inter-Turbine Temperature (ITT), between the compressor turbine and the first stage power turbine vane ring (station 5).

Description: - 10 individual thermocouples (chromel-alumel) - 1 positive bus bar (chromel-small terminal) - 1 negative bus bar (alumel-large terminal) - 1 trim probe - 1 T5 wiring harness

Note:

Engine operation at or above maximum temperature may damage or shorten hot section component's life

PT6A-60 SERIES TRAINING USE ONLY ENGINE INDICATING SYSTEM 7.4 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface TEMPERATURE INDICATING SYSTEM (T5)

THERMOCOUPLE WIRING HARNESS

TRIM PROBE

PRE-SB 13038 (A-60/61/65) TERMINAL BLOCK BUS-BAR

ALUMEL LEAD

CHROMEL LEAD INDIVIDUAL THERMOCOUPLE THERMOCOUPLE JUNCTION

PT6A-60 SERIES TRAINING USE ONLY ENGINE INDICATING SYSTEM 7.5 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface TEMPERATURE INDICATING SYSTEM (ITT)

Operation: Maintenance: - Check system loop resistance (continuity) As temperature increases, an increasing voltage is gener- - Check resistance of individual probe ated at the chromel/alumel junction of each thermocouple. - Check insulation resistance (harness, probe and trim probe) Uneven heat distribution within the gas path causes individ- - Check probes for heat response ual thermocouples to see different temperatures and gener- - Check Trim thermocouple adjustment ate different voltages.

To obtain an average reading, the thermocouples are con- Troubleshooting: nected in parallel. The indication generated is the average temperature of 10 specific locations (thermocouple tips) Problem Area Symptom within the gas path and therefore does not necessarily rep- resent the exact average temperature at station 5. The Burnt Probes T5 drops due to loss of probes exact average temperature is calculated at engine test and in hot spots is used to determine engine acceptance. Short Circuit To Ground T5 drops due to complete or A trim probe located over the inlet case is connected in par- partial loss of T5 signal allel with the 10 thermocouples to bias the average temper- Trim Probe Open Circuit T5 increases due to loss of ature reading. The resultant corrected temperature is read trimming function in the cockpit. The indication generated by the 10 probes at station 5 is trimmed down using the trim probe internal High Resistance On T5 T5 drops due to reduction of resistor. The smaller the resistance the greater the down- Circuit Between Engine T5 signal trim (the lower the ITT). And Aircraft Gage Trim Probe Resistance T5 increases if trim resistance The amount of trimming is a function of the trim probe inter- Drifting increases nal resistance. The resistance of the trim probe is adjusted T5 drops if trim resistance at engine test to match the required temperature trim. drops

PT6A-60 SERIES TRAINING USE ONLY ENGINE INDICATING SYSTEM 7.6 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface T5 SYSTEM SCHEMATIC

ALUMEL CHROMEL

VARIABLE SEALED BUS BARS & RESISTANCE THERMOCOUPLES (PRE SB 13338 & SB 14299)

TRIM PROBE

PT6A-60 SERIES TRAINING USE ONLY ENGINE INDICATING SYSTEM 7.7 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface TORQUE SYSTEM

Function: Maintenance:

Provide an accurate indication of the torque applied to the Check/calibrate the airframe torque transducer and gage propeller. (ref. to airframe maintenance manual).

Description: Troubleshooting: - Hydro-mechanical system - Floating first stage ring gear with helical splines Problem Area Symptom - Piston - Cylinder Control Valve Torque goes off scale (high) - Spring loaded oil control valve Stuck Open Worn Piston Torque indication low Operation: Seal Rings Set oil pressure to max limit Torque applied to the propeller induces a small rotational Defective Trans- Torque may indicate high or low and rearward movement of the first stage ring gear. This ducer/Gage movement is due to the helical splines on the ring gear. The ring gear pushes the piston and the control valve. Oil In RGB Torque fluctuation Static Line Moving the control valve to the rear, opens the metering orifice and allows more oil pressure to push on the piston Reference: against the ring gear mechanical force. A52, A64 1 psi = 30.57ft/lb The movement of the ring gear only stops when metered oil pressure in the torque meter chamber exactly balances the A60, A65 1 psi = 83.63ft/lb rearward force of the ring gear. Static air pressure inside the reduction gearbox acts on the torquemeter piston and A66 1 psi = 37.04ft/lb would cause incorrect (higher) torque reading. For this rea- A67 1 psi = 86.63ft/lb son, static pressure is sent to the transducer and subtracted from the torque reading. Hydrostatic lock is prevented by continuously bleeding oil from the pressure chamber.

PT6A-60 SERIES TRAINING USE ONLY ENGINE INDICATING SYSTEM 7.8 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface TORQUE SYSTEM

ELECTRIC TORQUE PRESSURE TORQUE TRANSDUCER SIGNAL (AIRFRAME)

FIRST STAGE PLANET GEAR REDUCTION GEARBOX TORQUE STATIC PRESSURE METER 1ST STAGE OIL BLEED RING GEAR ORIFICE

RING GEAR TORQUE OIL MOVEMENT PRESSURE

CONTROL VALVE

ENGINE OIL PRESSURE CYLINDER METERING ORIFICE

TORQUE PISTON

LOW POWER HIGH POWER

PT6A-60 SERIES TRAINING USE ONLY ENGINE INDICATING SYSTEM 7.9 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface CHIP DETECTOR

Function: Maintenance: - Inspect chip detector at interval specified by aircraft Provides an indication of metal particle contamination of the maintenance manual engine oil system. - Functionally test chip detector - 100hrs -> Check Continuity - 600hrs/12Mo. -> Function Check Description: - Two magnetic poles - Normally open circuit Warning: - Wired to a light in the cockpit (optional) - Self closing valve allows chip detector verification with- DO NOT OVERTORQUE THE CHIP DETECTOR out draining the RGB (except A64/66)

Operation:

When metal particles accumulate on the two magnetic poles and bridge the existing gap, the circuit closes.

Some installations use an indicator in the cockpit to warn the pilot or maintenance people that contamination is present. Other models rely on visual inspection and continuity check of the chip detector to detect contamination. Particles found on the chip detector can be analyzed and identified. Refer to chapter 70 of the Engine Maintenance Manual.

PT6A-60 SERIES TRAINING USE ONLY ENGINE INDICATING SYSTEM 7.10 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface CHIP DETECTOR

VALVE HOUSING VALVE

MAGNETIC POLES

VALVE CLOSED

VALVE OPEN

SELF CLOSING CHIP DETECTOR LOCKWIRE (A-52, A60, A61, A65 & SECURING LUG CERTAIN A67 MODELS ONLY) PREFORMED PACKING NON SELF CLOSING INSULATION CHIP DETECTOR MAGNETIC (A64, A66 & CERTAIN A67 MODELS) CHIP DETECTOR ELECTRICAL CONNECTOR

PT6A-60 SERIES TRAINING USE ONLY ENGINE INDICATING SYSTEM 7.11 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface NOTES

PT6A-60 SERIES TRAINING USE ONLY ENGINE INDICATING SYSTEM 7.12 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface IGNITION SYSTEM

IGNITION SYSTEM

PT6A-60 SERIES TRAINING USE ONLY IGNITION SYSTEM 8.1 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface IGNITION SYSTEM

Function: Exciter Box Specifications: Input voltage...... 9-30 VDC Provide the spark to ignite the fuel/air mixture. Input current...... 3.5 amp Operating Altitude ...... 0-50000 feet Description: Spark rate 10 VDC ...... 1 spark/sec - Airframe mounted ignition exciter 30 VDC...... 4 spark/sec - Two high tension cables Stored energy...... 4.7 joules - Two spark igniters Output voltage...... 8000 volts

Exciter Box: Operation: A sealed unit which transfers a DC low voltage input to a Activated by the pilot for engine start. The system can pulsed high voltage output. When the unit is energized, the operate continuously during adverse weather conditions to capacitor progressively charges until the voltage can ionize allow the engine to re-light in the event the of engine flame the spark gap then the capacitor discharges through the out. igniter plugs. Maintenance: Ignition Cables: - Ignition plugs are not life limited. Two cables carry the electrical energy from the exciter box - Inspect cooling holes of spark igniters for blockage. to the igniters. Each cable consists of an electrical lead sur- - Inspect igniter shell and electrode for erosion. rounded by an insulating tube contained in a flexible metal - Carry out functional test by disconnecting one ignition braiding. cable at the exciter box. Switch ignition on and listen for the spark. Spark Igniters: - Replace igniter plugs if dropped. Located at 4 and 9 o'clock positions on the gas generator - Check for fretting wear @ combustion chamber junc- case, the spark igniters are in the form of threaded plugs tion. with a central electrode enclosed in an annular semi-con- ducting material. When the voltage reaches a certain level, Warning: the air between the central electrode and the plug outer shell ionizes a high energy spark discharges from the elec- Wait six minutes after switching ignition off before trode. handling any ignition components.

PT6A-60 SERIES TRAINING USE ONLY IGNITION SYSTEM 8.2 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface IGNITION SYSTEM

IGNITERS POWER TURBINE COMBUSTION CHAMBER STATOR HOUSING LINER

GASKET

SPARK IGNITER

IGNITION CABLES

IGNITION EXCITER

0.300 IN. MAX.

0.015 IN. NEW ACCEPTABLE WORN OUT IGNITER WEAR

PT6A-60 SERIES TRAINING USE ONLY IGNITION SYSTEM 8.3 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface NOTES

PT6A-60 SERIES TRAINING USE ONLY IGNITION SYSTEM 8.4 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface PERFORMANCE

PERFORMANCE

PT6A-60 SERIES TRAINING USE ONLY PERFORMANCE 9.1 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface PERFORMANCE CHECK

Function: Permits verification of engine condition over a wide range of - From appropriate curves (Airframe M/M), determine: ambient temperatures without exceeding torque or T5 lim- - Target Torque. its. - ITT - Ng - Fuel Flow Performance Check Should Be Performed: - Determine parameter limits using tolerance from the - After engine installation. Airframe Maintenance Manual applied to the graph val- - Before and after hot section inspection. ues. - After FCU change. - Start engine and stabilize at idle for 5 min. - At regular interval. - No generator or pneumatic loads during performance test. - Set torque and Np as per chart. Description: - Stabilize engine at that power for 5 min. - Record actual ITT, Ng and Wf. Performance check curves establish engine parameter lim- - Compare recorded values of ITT, Ng and Wf to chart its for an acceptable engine at different atmospheric condi- parameters. tions. The check is performed at a given power where Tq - If values deviate from chart limits, troubleshooting and Np are constant and the values obtained for Ng, ITT action should be undertaken to restore engine perfor- and WF are compared to the limits obtained from the chart. mance.

Pre-H.S.I. Checklist: Procedure: 1. Calibrate engine gauges. - Ensure engine indicating system is properly calibrated. 2. Check for F.O.D. and wash compressor if needed. - Determine Outside Air Temperature (OAT). 3. Check the oil filter/screens and chip detectors. - Determine Pressure Altitude (Pa) or Barometric Press 4. Borescope (optional) - Set altimeter to 29.92 inHg to obtain Pressure Alti- 5. Carry out a ‘before’ and ‘after’ Performance run. tude - Set altimeter to 0 ft altitude to get field barometric pressure

PT6A-60 SERIES TRAINING USE ONLY PERFORMANCE 9.2 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface ENGINE PERFORMANCE CHECK (TYPICAL)

PT6A-60 SERIES TRAINING USE ONLY PERFORMANCE 9.3 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface PERFORMANCE CHECK (SHORTS INSTALL)

General: Static Maximum Take Off Power Check: Shorts installations use two types of performance checks. A Static MTOP check is required upon replacement of an 1. Static Reduced Power Check.(Static RTOP) engine after the Static Reduced Torque Check has been 2. Static Maximum Take Off Power check (Static MTOP) carried–out, or if a loss of performance is noted. 3. Reserve Power Check

1. Determine OAT and pressure altitude Static Reduce Power Check: 2. From POH, determine target torque and corresponding Ng, Wf and ITT target values. This check is performed on both engines after; 3. Start and stabilize engine at target torque (1 min.) a) installing an engine. 4. Check that observed values of Ng, Wf and ITT agree b) a rigging adjustment. with the graph values within tolerance. c) a propeller or engine component change. 5. If unacceptable, refer to PWC EMM for performance d) if requested by the flight crew. troubleshooting flow chart.

Reserve Power Check: Procedure: 1. Determine OAT and pressure altitude The Reserve Power Check is a ‘follow-up’ to a satisfactory 2. From POH, determine target torque and ITT limit. MTOP/RTOP check. 3. Start and stabilize engine at target torque (1 min.) 4. Record ITT and compare it to pre-determined limit. Must a) Set power as per POH, (2nd engine must be at Idle/ be within POH tolerances (approx +10 / -50°C). If out of off.) limit, carry-out a Static MTOP check. b) Activate Power Reserve Switch, confirm Static MTOP is achieved.

PT6A-60 SERIES TRAINING USE ONLY PERFORMANCE 9.4 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface PERFORMANCE CHECK (SHORTS INSTALL)

PT6A-60 SERIES TRAINING USE ONLY PERFORMANCE 9.5 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface PERFORMANCE CHECK (SHORTS INSTALL)

PT6A-60 SERIES TRAINING USE ONLY PERFORMANCE 9.6 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface ENGINE CONDITION TREND MONITORING (WEBECTM)

Function: Data Acquisition:

- Maintenance tool The accuracy of the WebECTM process depends on the - Allows user to monitor the engine performance quality of the data entered into a computer system. Cruise - Permits early detection of engine deterioration condition is the only flight configuration where engine reac- - Helps determine trouble area tion can be predicted. - Increase dispatch reliability - Allows to perform repairs at the most economical time To ensure validity of WebECTM data: - Allows to be on (soft time) for hot section inspection - Record data once per day, or every 6 hours Description: - Select the flight with the longest cruise that is at a rep- resentative altitude and airspeed WebECTM is a process of periodically recording engine - Allow the engine to stabilize 3 to 5 minutes without and aircraft instrument parameters and comparing them to ANY power lever movements a computer reference model. - The same flight configuration must be repeated (i.e. electrical load, bleed air extraction) Under specific ambient conditions, engine parameters such - Record data within a reasonable time frame as compressor speed (Ng), Inter-turbine Temperature (ITT) and fuel flow (Wf) are predictable. The difference between Data entry and Calculation: the actual engine parameters and the computer model values will be plotted as 3 deltas using a graphical chart Via PWC WebECTM method as illlustrated below. Plotting and Trend Analysis: Once a trend is established by the plotting of these deltas, any deviation would indicate some engine deterioration. Once the deltas are calculated, the computer does the plot- Analysis of the trend reveals extent of deviation and possi- ting and displays the result on screen or prints it. Analysis of ble need for corrective action. the trend can reveal extent of deviation and possible need for corrective action.

PT6A-60 SERIES TRAINING USE ONLY PERFORMANCE 9.7 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface WEBECTM (CON’T)

Plotting: Guidelines for interpretation of trend: Following computation, DELTA Ng, DELTA ITT, and DELTA Wf should be plotted on a continuous sheet. Flight log Net change of 10 to 15°C ITT: number may be used as the abscissa, although the trend Early sign of deterioration, that should be investigated when could also be recorded as a function of date or, preferably, convenient. as a function of engine running time in hours. Net change of 20 to 25°C ITT: Deterioration becoming more serious. Further running Definition Of Terms: could result in replacement of high cost hot section component. Corrective action should be taken as soon as possible Base Line: A straight line, derived from the average of the first 15 delta Net change of 30°C ITT: points for a particular engine with known conditions, which At this level, whether or not ITT is redlined, deterioration include a recently completed HSI, inspection of compres- has progressed to a point where serious engine damage is sors and a compressor wash. New or newly overhauled imminent engines also meet these conditions. Net change of .75 to 1% Ng: Net Change: Early signal of some deterioration should be investigated The change from the base line to a line passing through a when convenient delta point at a specific location on the graph. Net change over 1.5% Ng: Revision of Base Line: Action should be taken as soon as possible In the event the initial base line position improperly esti- mated, a revision of the base line values needs to be done. Note: A fault or change in the instrumentation calibration or an WebECTM courses are available. Please contact P&WC engine repair/H.S.I. will require the baseline to be re-estab- Customer Training department for the schedule lished.

Analysis: The analysis of the trend graph should be carried-out on a daily basis if possible, but not deferred for more than five days.

PT6A-60 SERIES TRAINING USE ONLY PERFORMANCE 9.8 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface ECTM SAMPLE PLOT

Ng % COMPRESSOR WASH HSI 4 2 0 -2 -4

50 25 0 ITT ˚C

Δ -25 -50

50 10 0 -10 -20

TIME PERIOD Wf pph Δ

PT6A-60 SERIES TRAINING USE ONLY PERFORMANCE 9.9 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface TBO AND HSI INTERVAL

• SB 13003 for PT6A-65 • SB 13303 for PT6A-52/60/61 Engine TBO H.S.I.3 • SB 13203 for PT6A-60AG, A-65AG • SB 14003 for PT6A-67R, 67D PT6A-52/60/61 3600 1800 • SB 14303 for PT6A-67AF, F PT6A-65 6000 2 1 • SB 14603 for PT6A-64, 66, 66A/B/D, 67, 67A/B/P/T 1200 /2000 • SB 14503 for PT6A-67AG PT6A-64/66/66A/66D/67/67A/67T 3000 1500 PT6A-67B/P, PT6A-64 ( post SB 3500 1750 to 2000 TBO Industry: 14089 or 14112 and 14261, 14308 ) Initial TBO applicable to all operators. PT6A-66B, PT6A-66 ( post SB 3600 1800 to 2000 TBO Fleet: 14112, 14274 and Piaggio Post- SB80-0194 ) TBO attained by individual operators for engines of the same model in their fleet only. PT6A-60AG/65AG/67AF/67AG/F 3000 1500 PT6A-67D/R 6000 2000 TBO Extension: 1) A65’s operated as airliners. Operators desiring TBO extension can submit a formal 2) A65’s operated as executive transports. request in writing together with details of sample engine log 3) N/A if operated under an approved WebECTM program book to: Manager, Technical Support, PT6 engines. HSI interval may be based on engine condition trend moni- Recommendations for time between-overhaul take into con- toring with borescope inspection at 2000 hours and every sideration the average effect of the many variables that 500 hours subsequently. (Ref SB 14003). affect overhaul life. These variables are average flight dura- tion, percentage of time at any given power level, climatic Modular Concept: conditions and environment, maintenance practices and An engine may be operated as 2 distinct modules, each engine utilization. having a logbook. This allows an operator to return the power section or gas generator for repair (or overhaul) and Under extreme conditions of very low utilization coupled keep the remaining module in service. Any spare module of with continuous operation in salt water atmosphere or the same model can be installed and operated as long as heavy sand environment periodic inspections in accordance each logbook reflects the applicable data. with the applicable maintenance instructions may indicate that maintenance actions are required prior to the recommended overhaul life.

PT6A-60 SERIES TRAINING USE ONLY PERFORMANCE 9.10 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface OPERATING LIMITS*

Description:

Operating limits define the upper and lower boundaries for all engine parameters observed in the cockpit during normal operation for each specific engine model. Excursion beyond these limits may accelerate engine wear and possibly lead to component malfunction.

For current operating limits, refer to applicable aircraft pilot operating handbook.

*Operating limits, listed here, are for reference only. They can be found in each Maintenance Manual in Section 71- 00-00.

PT6A-60 SERIES TRAINING USE ONLY PERFORMANCE 9.11 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface OPERATING LIMITS

PT6A-52 Power Setting SHP Torque Max ITT Ng NP Oil Pressure Oil Temp. lb-ft psig °C RPM % RPM PSI °C Take-off/Max Cont 850 2230 72.95 820 39000 104 2000 90 to 135 0 to 110 Max Climb 850 2230 72.95 775 39000 104 2000 90 to 135 0 to 110 Max. Cruise 850 2230 72.95 800 39000 104 2000 90 to 135 10 to 99 Normal Cruise 850 2230 72.95 775 39000 104 2000 90 to 135 10 to 99 Min. Idle - - - 750 21000 51 - - -40 to +110 Starting - - - 1000 - - - 200 (max) -40 (min) Transient - 2750 89.73 850 39000 104 2205 40 to 200 0 to 110 Max. Reverse 800 - - 760 - - - 90 to 135 0 to 99

PT6A-60A Power Setting SHP Torque Max ITT Ng NP Oil Pressure Oil Temp. lb-ft psig °C RPM % RPM PSI °C Take-off 1050 3625 43.34 820 39000 104 1700 90 - 135 0 – 110 Maximum Continuous 1050 3625 43.34 820 39000 104 1700 90 - 135 0 – 110 Takeoff / Climb 1000 3625 43.34 785 39000 104 1700 90 - 135 0 – 110 Max. Cruise 1000 3625 43.34 820 39000 104 1700 90 - 135 0 – 110 Normal Cruise 1000 3625 43.34 775 39000 104 1700 90 - 135 10 – 99 Min. Idle - - - 750 19000 51 - 60 (min) -40 - 110 Starting - - - 1000 - - - 200 (max) -40 (min) Transient - - - 850 39000 104 1870 40 – 200 -40 - 110 Max. Reverse 900 - - 760 - - 1650 90 - 135 0 - 99

PT6A-60AG Power Setting SHP Torque Max ITT Ng NP Oil Pressure Oil Temp. lb-ft psig °C RPM % RPM PSI °C Take-off 1050 3625 43.34 820 39000 104 1700 90 - 135 0 – 110 Maximum Continuous 1050 3625 43.34 775 39000 104 1700 90 - 135 0 – 110 Takeoff / Climb 1050 3625 43.34 775 39000 104 1700 90 - 135 0 – 110 Max. Cruise 1050 3625 43.34 775 39000 104 1700 90 - 135 0 – 110 Min. Idle - - - 750 21750 58 - 60 (min) -40 - 110 Starting - - - 1000 - - - 200 (max) -40 (min) Transient - - - 850 39000 104 1870 40 – 200 0 - 110 Max. Reverse 900 - - 760 - - 1650 100 - 135 0 - 104

PT6A-60 SERIES TRAINING USE ONLY PERFORMANCE 9.12 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface OPERATING LIMITS

PT6A-61 Power Setting SHP Torque Max ITT Ng NP Oil Pressure Oil Temp. lb-ft psig °C RPM % RPM PSI °C Take-off/Max Cont. 850 2230 72.95 800 39000 104 2000 90 - 135 0 – 110 Max. Cruise 850 2230 72.95 800 39000 104 2000 90 - 135 10 – 104 Normal Cruise 850 2230 72.95 775 39000 104 2000 90 - 135 0 - 99 Max Climb 850 2230 72.95 775 39000 104 2000 90 - 135 0 – 104 Min. Idle - - - 715 19000 51 - 60 (min) -40 - 110 Starting - - - 1000 - - - 200 (max) -40 (min) Transient - 2750 89.73 850 39000 104 2250 40 – 200 0 - 110 Max. Reverse 800 - - 760 - - - 90 - 135 0 - 99

PT6A-64 Power Setting SHP Torque Max ITT Ng NP Oil Pressure Oil Temp. lb-ft psig °C RPM % RPM PSI °C Take-off 700 2230 72.95 800 39000 104 2000(90.7%) 100 - 135 0 – 110 Max. Continuous 700 2230 72.95 800 39000 104 2000 100 - 135 0 – 104 MaxClimb/Cruise 700 2230 72.95 785 39000 104 2000 100 - 135 10 – 104 Min. Idle - - - 715 19000 51 - 60 (min) -40 - 110 Starting - - - 1000 - - - 200 (max) -40 (min) Transient - 2750 89.96 870 39000 104 2205(100%) 40 – 200 -40 - 110 Max. Reverse 700 - - 760 - - 1900 100 - 135 0 – 104

PT6A-60 SERIES TRAINING USE ONLY PERFORMANCE 9.13 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface OPERATING LIMITS

PT6A-65B Power Setting SHP Torque Max ITT Ng NP Oil Pressure Oil Temp. @ OAT lb-ft °C RPM % RPM PSI °C Take-off 1100 3625 43.34 820 39,000 104 1700 90 to 135 0 to 110 Maximum Continuous 1100 3625 43.34 810 39,000 104 1700 90 to 135 0 to 110 Maximum Climb 1000 3625 43.34 800 39,000 104 1700 90 to 135 0 to 110 Norm cruise 1000 3625 43.34 750 39,000 104 1700/100% 90 to 135 10 to 99 Min. Idle - - 700 21,750 58 - 60 minimum -40 to 110 Starting - - 1000 - - - 200 max -40 minimum Transient 5100 870 39,000 104 1870/110% 40 to 200 0 to 110 Max. Reverse 900 - 760 - - 1650/97% 90 to 135 0 to 99

PT6A-65AR Power Setting SHP Torque Max ITT Ng NP Oil Pressure Oil Temp. lb-ft °C RPM % RPM PSI °C Take-off 1424 4400 52.61 855 39,000 104 1700/100% 90 to 135 10 to 110 Maximum Continuous 1220 3825 45.74 840 39,000 104 1700 90 to 135 10 to 110 Maximum Cruise/ 956 3625 43.34 770 39,000 104 1700 90 to 135 10 to 105 climb Min. Idle - - - 715 21,000 56 - 60 minimum -40 to 110 Starting - - - 1000 - - - 200 max -40 minimum Transient 5100 61.00 870 39,000 104 1870/110% 40 to 200 -40 to 110 Max. Reverse 900 - - 760 - - 1650/97% 90 to 135 10 to 105

PT6A-60 SERIES TRAINING USE ONLY PERFORMANCE 9.14 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface OPERATING LIMITS

PT6A-65AG Power Setting SHP Torque Max ITT Ng NP Oil Pressure Oil Temp. lb-ft °C RPM % RPM PSI °C Take-off 1300 4017 48.03 810 39,000 104 1700/100% 90 to 135 0 to 110 Maximum Continuous 1220 3825 45.74 810 39,000 104 1700 90 to 135 0 to 110 Maximum Cruise/ 956 3625 43.34 800 39,000 104 1700 90 to 135 0 to 110 climb Min. Idle - - - 750 21,000 56 - 60 minimum -40 to 110 Starting - - - 1000 - - - 200 max -40 minimum Transient 5100 60.98 870 39,000 104 1870/110% 40 to 200 -40 to 110 Max. Reverse 900 - - 760 - - 1650/97% 90 to 135 10 to 110

PT6A-66A Power Setting SHP Torque Max ITT Ng NP Oil Pressure Oil Temp. lb-ft °C RPM % RPM PSI °C Take-off 850 2230 60.21(72.95) 830(800) 39,000 104 2000/90.7% 90 to 135 0 to 104 Maximum Continuous 850 2230 60.21(72.95) 830(800) 39,000 104 2000 90 to 135 0 to 104 Maximum Cruise/ 850 2230 60.21(72.95) 820(785) 39,000 104 2000 90 to 135 0 to 104 climb Min. Idle - - - 750(759) 19,000 51 - 60 minimum -40 to 110 Starting - - - 1000 - - - 200 max -40 minimum Transient 2750 74.24(89.96) 870 39,000 104 2205/100% 40 to 200 0 to 110 Max. Reverse 800 - - 760 - - 1900/86.2% 90 to 135 0 to 104

PT6A-66D Power Setting SHP Torque Max ITT Ng NP Oil Pressure Oil Temp. lb-ft °C RPM % RPM % PSI °C Take-off 850 2230 72.95 850 39,000 104 2000 90.7 100 to 135 0 to 104 Maximum Continuous 850 2230 72.95 840 39,000 104 2000 90.7 100 to 135 0 to 104 Maximum Cruise/ 850 2230 72.95 840 39,000 104 2000 90.7 100 to 135 0 to 104 climb Min. Idle - - - 750 19,000 51 - 60 minimum -40 to 110 Starting - - - 1000 - - - 200 max -40 minimum Transient 2750 90.0 870 39,000 104 2205 100 40 to 200 0 to 110 Max. Reverse 800 - - 780 - - 1900 86.2 100 to 135 0 to 104

PT6A-60 SERIES TRAINING USE ONLY PERFORMANCE 9.15 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface OPERATING LIMITS

PT6A-67A Power Setting SHP Torque Max ITT Ng NP Oil Pressure Oil Temp. lb-ft °C RPM % RPM PSI °C Take-off 1200 3708 44.34 850 39,000 104 1700/100% 90 to 135 10 to 110 Max Cont 1200 3708 44.34 840 39,000 104 1700 90 to 135 10 to 110 Max. Cruise / Climb 1000 3625 43.35 840 39,000 1700 90 to 135 10 to 105 Norm Cruise / Climb 1000 3625 43.35 820 39,000 1700 90 to 135 10 to 105 Min. Idle - - - 750 19,000 51 - 60 minimum -40 to 110 Starting - - - 1000 - - - 200 max -40 minimum Transient 5100 60.98 870 39,000 104 1870/110% 40 to 200 0 to 110 Max. Reverse 900 - - 760 - - 1650/97% 90 to 135 10 to 105

PT6A-67AG Power Setting SHP Torque Max ITT Ng NP Oil Pressure Oil Temp. lb-ft °C RPM % RPM PSI °C Take-off 1350 4170 49.87 800 39,000 104 1700/100% 90 to 135 10 to 110 Max Cont/ Cruise/ 1220 3770 45.07 800 39,000 104 1700 90 to 135 10 to 110 climb Min. Idle - - - 750 19,000 51 - 60 minimum -40 to 110 Starting - - - 1000 - - - 200 max -40 minimum Transient 5100 60.98 870 39,000 104 1870/110% 40 to 200 0 to 110 Max. Reverse 900 - - 760 - - 1650/97% 90 to 135 10 to 105

PT6A-60 SERIES TRAINING USE ONLY PERFORMANCE 9.16 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface OPERATING LIMITS

PT6A-67B Power Setting SHP Torque Max ITT Ng NP Oil Pressure Oil Temp. lb-ft psig °C RPM % RPM psig °C Take-off 1200 3708 44.34 800 39000 104 1700/100% 90 to 135 10 to 110 Maximum Continuous 1200 3708 44.34 800 39000 104 1700 90 to 135 10 to 110 Maximum Cruise/ 1000 3090 36.95 760 39000 104 1700 90 to 135 10 to 110 climb Min. Idle 750 19000 51 - 60 min. -40 to 110 Starting 1000 - 200 max. -40 min. Transient 5100 61.00 870 39000 104 1870/110% 40 to 200 0 to 110 Max. Reverse 900 760 1650/97% 90 to 135 10 to 105

PT6A-67D Power Setting SHP Torque Max ITT Ng NP Oil Pressure Oil Temp. lb-ft psig °C RPM % RPM psig °C Take-off 1279 3950 47.23 800 39000 104 1700/100% 90 to 135 10 to 110 Maximum Continuous 1214 3750 44.84 780 39000 104 1700 90 to 135 10 to 110 Maximum Cruise/ 1106 3750 44.84 760 39000 104 1700 90 to 135 10 to 110 climb Min. Idle 750 19000 51 - 60 min. -40 to 110 Starting 1000 - - - 200 max. -40 min. Transient 5100 61.00 870 39000 104- 1870/110% 40 to 200 -40 to 110 Max. Reverse 900 760 - 1650/97% 90 to 135 10 to 105

PT6A-67F Power Setting SHP Torque Max ITT Ng NP Oil Pressure Oil Temp. lb-ft psig °C RPM % RPM psig °C Take-off 1600 4943 60.25 870 39000 104 1700/100% 90 to 135 10 to 110 Maximum Continuous 1600 4943 60.25 870 39000 104 1700/100% 90 to 135 10 to 110 Maximum Climb/ 1550 4789 58.37 815 39000 104 1700/100% 90 to 135 10 to 110 Cruise 1350 4634 56.48 795 Min. Idle 750 19000 50.7 - 60 min. -40 to 110 Starting 1000 - - - 200 max. -40 min. Transient 6092 74.25 910 39000 104- 1870/110% 40 to 200 -40 to 110 Max. Reverse 900 760 - 1650/97% 90 to 135 10 to 105

PT6A-60 SERIES TRAINING USE ONLY PERFORMANCE 9.17 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface OPERATING LIMITS

PT6A-67P Power Setting SHP Torque Max ITT Ng NP Oil Pressure Oil Temp. lb-ft psig °C RPM % RPM psig °C Take-off 1200 3708 44.34 850 39000 104 1700/100% 90 to 135 10 to 110 Maximum Continuous 1200 3708 44.34 840 39000 104 1700/100% 90 to 135 10 to 105 Maximum Climb/ 1200 3708 44.34 820 39000 104 1700/100% 90 to 135 10 to 105 Cruise 1000 3090 36.95 820 Min. Idle 750 19000 51 - 60 min. -40 to 110 Starting 1000 - - - 200 max. -40 min. Transient 5100 61.00 870 39000 104- 1870/110% 40 to 200 -40 to 110 Max. Reverse 900 760 - 1650/97% 90 to 135 10 to 105

PT6A-67R & T Power Setting SHP Torque Max ITT Ng NP Oil Pressure Oil Temp. lb-ft psig °C RPM % RPM psig °C Take-off 1424 4400 52.61 855 39000 104 1700/100% 90 to 135 10 to 110 Alt. take-off (R only) 1281 3960 47.35 825 39000 104 1700 90 to 135 10 to 110 Maximum Continuous 1220 3825 45.74 840 39000 104 1700 90 to 135 10 to 110 Maximum Cruise/ 1020 3760 44.96 790 39000 104 1425 90 to 135 10 to 105 climb Min. Idle - - 755 21000 56 - 60 min -40 to 110 Starting - - 1000 - - - 200 Max -40 min. Transient 5100 61.00 870 39000 104 1870/110% 40 to 200 0 to 110 Max. Reverse 900 - - 760 - - 1650 90 to 135 10 to 105

PT6A-60 SERIES TRAINING USE ONLY PERFORMANCE 9.18 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface ROTOR COMPONENTS - SERVICE LIFE

Description: Flight Count Factor:

Certain rotating components are subject to low-cycle This is an index of severity. An indication of how much a fatigue due to cyclic operation of the engine. Additionally, component is affected during the engine operation. This is other factors such as high frequency fatigue and metallurgi- a multiplier and will change for a given component if cal changes related to time rather than flight cycles are con- installed in a different engine. sidered. As a result, these parts must be removed from service when the cycle limit is reached. If your missions include more flights than starts, component cycle life may be calculated in accordance with the following Reference: formula: - SB 13002 for PT6A-52/60/61/65 - SB 13202 for PT6A-65AG Total Cycles = - SB 14002 for PT6A-64,66,67, 67B/D/P [Starts + ( Flights-Starts ) ] x Flight Count Factor - SB 14302 for PT6A-67AF Abb. Cycle Factor - SB 14502 for PT6A-67AG/67F Operators having missions, which include many touch-and- go flights or a frequency of scheduled in-flight shutdowns (such as used during pilot training) or which include more Airworthiness Regulations Require The Operator To: than 10 flights per hour must submit their mission profiles to - Log engine hours, starts and aircraft flights Pratt and Whitney Canada for life cycle analysis. - Calculate and record these hours and cycles

Definition Of A Cycle:

A flight preceded by a start and followed by a shutdown.

Abbreviated Cycle:

A flight, from wheels up to wheels down, but without a start or shutdown.

PT6A-60 SERIES TRAINING USE ONLY PERFORMANCE 9.19 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface OVERTORQUE CHART (TYPICAL)

3000 75

TO SHIPAN OVERHAUL POWER SECTION FACILITY

OUTPUT TORQUE (FT-LBS) TORQUEMETER PRESSURE (PSI) RECORD IN LOG BOOK

NO ACTION REQUIRED

0 0 01 TIME 2345 (MINUTES) 20 SECONDS

PT6A-60 SERIES TRAINING USE ONLY PERFORMANCE 9.20 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface OVERTEMPERATURE CHART (TYPICAL)

2000

C A

INTER TURBINE TEMPERATURE ( C° ) A B

NO ACTION REQUIRED * ITT RED LINE 0 5 10 15 20 25 30 TIME (SECONDS) A = DETERMINE & CORRECT CAUSE OF OVERTEMPERATURE - START OVERTEMP, INSPECT P.T. BLADES THROUGH EXHAUST - RECORD IN LOG BOOK B = PERFORM HOT SECTION INSPECTION C = SHIP ENGINE TO AN OVERHAUL FACILITY

* ITT RED LINE = MAXIMUM TAKE OFF ITT

PT6A-60 SERIES TRAINING USE ONLY PERFORMANCE 9.21 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface ENGINE TROUBLESHOOTING

Effective engine troubleshooting infers monitoring engine Troubleshooting of problems related to internal engine com- parameters on a regular basis, using performance check ponents is generally divided in 2 areas: and engine condition trend monitoring. - Compressor section - Hot section. Effective troubleshooting can be divided into four steps: The compressor section refers to all the components of the 1. Evaluate the symptoms main gas path. This starts from the aircraft inlet and 2. Logically isolate the possible cause of the problem includes the gas generator where P3 air fills the cavity 3. Try quick fixes when possible. around the combustion chamber liner. 4. Determine the corrective action required to solve the problem The hot section is composed of all the components starting from the combustion chamber liner down to the exhaust Remember that troubleshooting is done by comparing duct including all the vane rings and the turbines. engine parameters with a set of reference values for a good engine or by looking at the trend of the parameters of one engine over a period of time.

Propeller speed and torque are the indication of power produced by an engine. Any serious troubleshooting should begin with the calibration of the instruments used in the process.

Note: Chapters 10 and 11 cover troubleshooting of fuel and propeller systems.

PT6A-60 SERIES TRAINING USE ONLY PERFORMANCE 9.22 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface PERFORMANCE TROUBLESHOOTING

Introduction: Systematic Approach: - The following information is a guide only. - Preferred approach - Refer to the appropriate aircraft or engine mainte- - Gathering of all applicable information nance manual as necessary. - Analysis of engine symptoms - Determination of most probable cause - Corrective actions Troubleshooting: - Confirm results - Technique used to logically isolate the cause of an engine problem . This method requires a good knowledge of normal and - Determine the corrective maintenance action(s). abnormal engine operation, systems operation as well as - Resolve the problem in a timely manner. the ability to use technical manuals efficiently.

The systematic approach increases the chances that you Shotgun Approach: are looking in the correct area for the problem, so that pre- - Based on a "Trial and Error" method. cious man-hours and material are not wasted on tasks that - Used by personnel with minimal knowledge of engine provide no resolution to the problem. operation and troubleshooting techniques. - This time consuming method is not cost effective and indicates that some form of training is required.

By The Book Approach:

Effective but time consuming method used by maintenance technicians who follow all necessary troubleshooting procedures from technical manuals. This method requires some knowledge of engine construction and operation.

PT6A-60 SERIES TRAINING USE ONLY PERFORMANCE 9.23 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface PERFORMANCE TROUBLESHOOTING (CONT’D)

The Basics: tance limits on compressor FOD. The extended limits are - Understand the problem approximately double the previous ones but are acceptable - Simultaneous review of ECTM* and recent past history providing that engine performance remains acceptable. - Pilot reports, and maintenance logs Therefore, if the FOD is towards the high side of the A review of the ECTM plots for the past three to six months extended limits, heavy erosion is visible or the engine is in conjunction with a review of the past thirty days of pilot having performance difficulties then it is likely the compres- write-ups and maintenance actions are the two most useful sor has reached the refurbishment point. Further attempts tools to be employed in defining the problem and setting a to repair the engine on-wing would be futile. plan for corrective action. It is recommended these records be available on-site where the aircraft maintenance is being Compressor Wash: performed and not in a locked office a few hundred miles - How long since last wash away where the individual has gone home for the night. If - Does ECTM show extended gradual shift right of all this is not the case, then the maintenance crew should have parameters some way of accessing the information. - Experience has shown 15 to 20 °C recovery when washed ECTM has the ability to tell you if the problem is in the cold - A wash may be all you need section or hot section of the engine. A step shift of only one parameter is a likely instrumentation problem. If it has been some time since the last wash and the compressor looks dirty, it is recommended a ground perfor- Pilot write-ups and maintenance logs can offer very valid mance run be carried out, followed by engine wash, and clues; for example if the pilot report has been repeated sev- then finally by another ground performance run. A compar- eral times dated back to seven days previous. One could ison of the pre and post wash run data will indicate how go back and review the maintenance actions carried out just dirty the engine was and if any further troubleshooting is prior to the first pilot report to see if the problem was intro- required. We have seen reported "major performance loss" duced by the maintenance action. being rectified by nothing more than two successive engine washes. Compressor Health: * Inspection for FOD and erosion Note: * Increased manual limits ECTM = Engine Condition Trend Monitoring * Compressor may have reached refurbishment point One of the first areas that one should look at on the engine is the compressor intake. PWC has extended the accep-

PT6A-60 SERIES TRAINING USE ONLY PERFORMANCE 9.24 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface PERFORMANCE TROUBLESHOOTING (CONT’D)

Instrument Calibration: From the previous example, the importance of instrument - How long since last calibration. calibration can not be overemphasized. - Accurate calibrations are worth the effort. - OAT, PA, and IAS are used in normalization process and thereby affect ECTM accuracy . Intake Deviations: - Erroneous OAT, PA, and TQ affects targets for the day. - Actual running data has shown up to 35° C ITT differ- - If ECTM data shows a step jump in ITT only, one ential between separator deployment and retraction should suspect an instrumentation problem in the ITT - Ice vane drop/out of adjustment will also cause perfor- system. mance deterioration and parameter fluctuation - Similarly if all parameters are high, a torque indication problem is likely. Eliminate Cabin Bleed Leaks: Remember ECTM plots are produced by normalization pro- - Ground run with cabin bleeds blanked at engine flange cess of certain inputs and then comparing the normalized - Compare blanked and un-blanked run data data with actual recorded. Outside air temperature, pres- - Leaking P3 pre-coolers and defective temp control sure altitude, prop speed, and airspeed are inputs to the valves have caused up to 60°C rises in ITT normalization formula. If these parameters are out of calibration, the ECTM plots will be unreliable as a troubleshooting tool. Carry out a ground performance run with the cabin bleed systems in the normal off position. Follow this with a Outside air temperature and pressure altitude are used to ground performance run with the bleeds blanked at the determine target torque for the day in doing ground perfor- engine flange. It is important to blank the system at the mance runs. Errors in these instruments will lead to selec- engine flange rather than at some other convenient location of the wrong target torque for the day. If the torque tion. transducer calibration is low, the actual engine torque will be higher than what is indicated. This is perceived as the engine being temperature limited, as well, fuel flow and gas generator speed will be higher than normal.

PT6A-60 SERIES TRAINING USE ONLY PERFORMANCE 9.25 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface PERFORMANCE TROUBLESHOOTING (CONT’D)

Eliminate Cabin Bleed Leaks (Cont'd): Trim Determination: - Trim on/off runs to determine if trim compensation is Compare the results of the two runs. If the parameters of correct. the run with the bleeds blanked appear lower, you have a - Not a "dial as required system" leak or component malfunction in the bleed system that - Do not readjust existing trim probes. requires rectification.

At the same time as the bleeds blanked run is done, it is Do two ground runs at take-off power, one with the trim also a convenient opportunity to do a bleed valve closing compensator connected and one with it disconnected and point check and a T5 trim determination check. compare the results. It is recommended to use a precision tester (i.e. Barfield) to monitor ITT during these runs rather Bleed Valve Closing: than the cockpit gauge. The delta in ITT between these two - Is the BOV closure point correct ? runs should be within ±10% of engine data plate trim value. - Late closing bleed valve results in high ITT. - Sticking bleed valve results in intermittent power. If the delta is greater than ±10%, the T5 trim compensator - Regular scheduled BOV checks. should be replaced. Previously installed or adjusted trim - Closure point shifts with time. compensators must not be readjusted. - Some engines have classified CT baffle. - Controls BOV closing pressure air. - Facilitates seat adjustment. - Mixing pre and post SB hardware results in BOV closing problems.

Some engine models have a classified baffle bolted to the number two bearing cover. The size of the inner diameter of this baffle controls the air to the bleed valve, therefore, when working in this area pay particular attention not to intermix pre and post SB hardware. Intermixing of hardware results in BOV timing difficulties.

PT6A-60 SERIES TRAINING USE ONLY PERFORMANCE 9.26 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface PERFORMANCE TROUBLESHOOTING (CONT’D)

Borescope Inspection: Engines are assembled; performance tested and trimmed - Borescope engine to confirm hot section distress. with a particular set of CT and first stage PT vane classes. - Does what you see with the borescope agree with the It is important to know what these classes were as a refer- ECTM plots. ence point for future on-wing maintenance. - Do you want to run to extended borescope limits. When it becomes necessary to replace a CT or Power Tur- If the ECTM plots show typical hot section deterioration (ris- bine (PT) vane on-wing, one must go back to the last test ing ITT and decreasing NG) you should see distress of the cell performance run vane class matching as a reference for Compressor Turbine (CT) vane and/or CT blades when you replacement, not necessarily the class that was removed. borescope the hot section. PWC recognize that it is not always possible to obtain the Some maintenance manuals have the extended inspection exact same class vane as required on short notice. To limits incorporated (72-00-00). A number of factors must be allow some flexibility, PWC recommends that one stays taken into consideration when opting to run to the extended within ±0.03 of a class on CT and ±0.1 of a class on PT of limits. The two factors are whether there is a large ITT delta those installed at last test cell run. upshift in the ECTM plots and how long the engine has been operating this way. If the borescope inspection Maintaining a small spreadsheet for your complete fleet is a reveals a burned through vane airfoil one must carefully useful tool and worth the effort. The spreadsheet should assess the decision to continue in service. As this condition contain engine serial number with what class vanes were excites the CT blade that can lead to blade cracking and installed at last test cell run and what classes are currently possible failure. installed. It can give ready picture of what engines may not be ideally matched. It can also speed up the process in hot Engine Matching: section planning. - Has engine performance been questionable since last HSI. - What classes of CT and PT vanes were installed at last test cell run. - What vane classes are installed now. - Use same class within ± .03 CT and ± .1 PT - Keep a log of important engine data, BOV seat, CT baffle, vane class etc.

PT6A-60 SERIES TRAINING USE ONLY PERFORMANCE 9.27 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface NOTES

PT6A-60 SERIES TRAINING USE ONLY PERFORMANCE 9.28 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface FUEL SYSTEM

FUEL SYSTEM

PT6A-60 SERIES TRAINING USE ONLY FUEL SYSTEM 10.1 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface POWER MANAGEMENT

- 3 lever control system Propeller Lever: - 2 levers on PT6A-66 and A-67B/P - Connected to the propeller speed control lever on the top of the propeller governor (CSU). Power Lever: - Controls the propeller speed in the governing mode. - Controls the compressor speed in forward as well as - Allows feathering of the propeller. reverse thrust mode. - Controls the propeller pitch in reverse. Manual Override (Power Lever): - Connects to a cam cluster located on the accessory - Single engine aircraft only. gearbox. - Controls Ng directly in the event of a loss of P3 air - Cam cluster transmits power lever movement to the pressure at the FCU. fuel control unit. - Controls fuel flow from minimum to maximum flow - The FCU controls Ng. stops. - Used in forward mode only. Below idle, movement of the power lever affects both Ng and the beta valve to change the propeller blade angle from Note: positive pitch to reverse pitch as power is gradually Engines operated with two levers have a ‘single speed’ pro- increased in reverse. peller governor. (Pilatus PC-XII aircraft PT6A-67B/P).

Fuel Lever (Condition Lever): - Cut-off position stops fuel flow to the combustion chamber and causes the engine to shut down - Allows to set Ng from low idle to high idle - Low idle is the minimum Ng allowed - High idle is the minimum power used in flight

When the correct Ng is reached, the low idle position is selected to allow fuel into the combustion chamber.

PT6A-60 SERIES TRAINING USE ONLY FUEL SYSTEM 10.2 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface POWER MANAGEMENT

MIN. POWER TAXI RANGE POWER REVERSE RANGE MAX. POWER MIN. RPM BETA FEATHER MAX. RPM

POWER PROPELLER LEVER LEVER CAM ASSY PROPELLER GOVERNOR

LOW IDLE SHUT-OFF HIGH IDLE

FUEL CONDITION LEVER

PT6A-60 SERIES TRAINING USE ONLY FUEL SYSTEM 10.3 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface FUEL SYSTEM

Function: Alternate/Emergency Fuels:

Provides the engine with clean fuel at the required pressure Minimize use of AVGAS. AVGAS may contribute to acceler- and flow to permit control of engine power. ate hot section deteriorations. Run AVGAS a maximum of 150 hrs between overhauls. Components: - Fuel heater Operating time on AVGAS is computed on the basis of - Fuel pump quantity used versus average engine consumption. The - Fuel control unit operation of P&WC commercial engines, covered by this - Flow divider training manual, on fuel other than the approved jet fuels is - Fuel nozzles (14) not permitted without the express permission of P&WC. - Fuel drain valves (2)

Fuel And Additives: - SB 13044 for A-52/60/61/65. - SB 13244 for A-65AG. - SB 14004 for A-64/66/67. - SB 14504 for A67AG/F - SB’s indicated above list minimum requirements for acceptable engine fuel.

- Additives such as; - anti-corrosion. - anti-icing. - thermal stability additives. - Anti-microbial

- Use of Aviation Gasoline (AVGAS) is limited to 150 hours per engine between overhaul periods (TBO). - Diesel fuel is permitted for agricultural use only.

PT6A-60 SERIES TRAINING USE ONLY FUEL SYSTEM 10.4 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface FUEL SYSTEM

CONDITION LEVER

BYPASS POWER PORT LEVER

AIR Py AIR FUEL OUT TO CSU FUEL MANIFOLD ADAPTER FUEL PUMP DRAIN VALVES P3 IN FUEL IN FUEL CONTROL UNIT

FUEL CONTROL UNIT(FCU) FLOW DIVIDER VIEW A A FUEL DELIVERY TUBE

FUEL HEATER P3 AIR TO FCU FUEL FROM AIR FUEL FROM TANK FUEL PUMP FUEL (AIRFRAME) TO FCU

PT6A-60 SERIES TRAINING USE ONLY FUEL SYSTEM 10.5 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface FUEL SYSTEM

Description:

Fuel from the aircraft tank is sent to the fuel heater via one or more airframe boost pumps. From the fuel heater, fuel is directed to the fuel pump. The fuel pump sends the fuel to the fuel control unit (FCU) which determines the quantity of fuel required by the engine to produce the power requested through the power lever and according to the ambient conditions.

The excess fuel is returned to the inlet of the fuel pump and the fuel flow going to the engine goes through the fuel flow meter to indicate the fuel consumption in the cockpit. Then, the fuel reaches the flow divider where it is directed to the primary and secondary fuel manifolds to supply all the nozzles. The fuel nozzles atomize the fuel in the combustion chamber to sustain the combustion.

PT6A-60 SERIES TRAINING USE ONLY FUEL SYSTEM 10.6 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface FUEL SYSTEM SCHEMATIC

FUEL HEATER FUEL CONTROL UNIT FUEL PUMP UNIT FUEL METERING INPUTS OIL OUT OIL IN INLET FILTER PUMP (SELF RELIEVING) OUTLET FILTER NG PLA BYPASS BYPASS FUEL LEVER PRESSURE P3 AIR REGULATING VALVE

FUEL TANK FLOW METER FUEL DISTRIBUTION (AIR FRAME) BOOST PUMP (AIRFRAME) PRIMARY SECONDARY PPH MANIFOLD MANIFOLD

FLOW IGNITERS COMBUSTION DIVIDER CHAMBER

P3 AIR

FUEL INLET PRESSURE DUMP OR ACCUMULATOR FUEL NOZZLES OIL INLET PRESSURE PUMP DELIVERY PRESSURE BYPASS FUEL METERED FUEL PRIMARY FUEL MANIFOLD SECONDARY FUEL MANIFOLD

PT6A-60 SERIES TRAINING USE ONLY FUEL SYSTEM 10.7 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface FUEL HEATER

Function: Maintenance: - Heat the fuel to prevent ice crystal formation - Replace unit if defective. - Heat the FCU housing to prevent condensation from - Repair the coating on fuel heater as per engine Main- freezing in the bellows assembly tenance Manual. - Preheat the fuel for FCU calibration

Troubleshooting: Description: - Verify operation by touching the fuel filter bowl after - Housing shutdown. Should be warm but not hot (≈27°C / 80°F). - Fuel passages - A template temperarure recorder can be used to deter- - Scavenge oil passages mine if thermal element is good (refer to the Mainte- - Thermal element sensing fuel temperature nance Manual). - Internal damage may cause oil to mix with fuel and result in high oil consumption when engine is running. Operation: - Internal damage may also cause fuel to mix with the oil in static conditions. Cold fuel from the aircraft boost pump enters the fuel heater and surrounds the thermal element. The cold thermal element contracts and allows scavenge oil from the accessory Symptom Cause Effect gearbox to travel across the heat exchanger. Heat from the oil transfers to the fuel raising it's temperature. Fuel Too Hot Thermal element or Fuel pump control valve cavitation At 21°C the thermal element begins to expand and moves Fuel Too Cold Thermal element or Possible filter the valve to the right. In this position, scavenge oil from the control valve blockage (ice) accessory gearbox progressively bypasses the fuel heater and the fuel temperature begins to stabilize. The spring High Oil Con- Heat exchanger Oil leak in the located at the back of the valve pushes it back to the left sumption internal leakage fuel (heating position) when the fuel temperature drops. During operation, the thermal element constantly reacts to adjust fuel outlet temperature.

PT6A-60 SERIES TRAINING USE ONLY FUEL SYSTEM 10.8 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface FUEL HEATER

FUEL OIL OUTLET INLET

SLIDE VALVE

THERMAL PUSH ROD RETURN SPRING ELEMENT

OIL FUEL OUT OUTLET

OIL IN OIL OUT

FUEL FUEL IN INLET

FUEL PASSAGE OIL PASSAGE

PT6A-60 SERIES TRAINING USE ONLY FUEL SYSTEM 10.9 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface FUEL PUMP

Function: Outlet Filter Bypass Valve: - Bypass fuel if filter gets restricted Provide clean fuel under pressure to the fuel control unit. - Set to open at 15-25 psid

Description: - Single stage Bypass Pressure Regulating Valve: - Gear type pump - Maintains bypass pressure above a minimum to mini- - Brass bushings loaded against pump gears mize fuel leakage at the brass bushing - Carbon seals prevent fuel leak - Set to open at 10 - 35 psid - Inlet and outlet fuel filters

Operation: Pump Capacity (Typical): From the fuel heater, fuel enters the fuel pump housing and passes through the inlet filter, then through the pump. Fuel Ng Wf Pressure is filtered a second time through the outlet filter before being % pph psi delivered to the fuel control unit. Two carbon face seals prevent fuel from leaking out of the pump. A bypass pres- 13 % 200 175 sure regulating valve is mounted on the FCU bypass return line to ensure a minimum amount of pressure is maintained 100 % 1600 800 on the brass bushings to reduce fuel leakage when pump Typical engine Wf at 1000 SHP ≈ 500 pph pressure increases.

Inlet Filter: - 74 micron screen. Maintenance: - Cleanable (600hrs) - Inspect inlet and outlet filters at specified intervals. - Bypass feature - Inspect for reddish-brown stain in drain port of fuel - Bypass at 1.5 psid pump (Sundstrand pumps only). - Replace fuel pump if the engine is operated without Outlet Filter: airframe boost pressure for more than 10 hours. - 10 micron non-metallic type filter - Disposable (600hrs)

PT6A-60 SERIES TRAINING USE ONLY FUEL SYSTEM 10.10 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface FUEL PUMP

HIGH PRESSURE FUEL TO FCU

OUTLET FILTER BYPASS FILTER VALVE

CARBON SEAL CARBON SEAL BRASS BUSHINGS

FCU BYPASS COUPLING TO RETURN ACCESSORY GEARBOX

INLET FILTER (SELF RELIEVING)

BYPASS PRESSURE REGULATING VALVE FUEL INLET PRESSURE LOW PRESSURE FUEL BYPASS FUEL FROM FUEL HEATER PUMP DELIVERY PRESSURE

PT6A-60 SERIES TRAINING USE ONLY FUEL SYSTEM 10.11 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface FUEL CONTROL UNIT (MAIN FLOW)

Function: Minimum Flow: - Provides minimum fuel to start engine and prevents Deliver the required amount of fuel at the required pressure flame out during rapid deceleration to the fuel nozzles. - Factory set at ≈90 pph

Pressure Relief Valve: Pump Unloading Valve: - Prevents system over pressurization - Pilot operated to start or shutdown the engine - Dumps excess fuel to the bypass - Opens when pilot shuts down the engine - Factory set to open at 1350 psid - Dumps P2 fuel to P0 - P2 becomes equal to P0 - Shutdown valve closes Bypass Valve: - Factory set - Maintains delta pressure P1-P2 constant at 53 psid - Bypass fuel in excess of engine requirement - Fuel pump delivers more fuel than required Minimum Pressurizing And Shutdown Valve: - Bypass fuel returns to the pump - Allows the fuel control to pressurize before providing - Factory adjusted to limit engine acceleration rate fuel to the engine - Improves fuel metering on start During acceleration, more fuel is required in the P2 line. To - Works in conjunction with the pump unloading valve supply the need, less fuel is dumped to Po by the bypass for engine shut down valve. During deceleration, the opposite applies. - Opens at 100 psid

PT6A-60 SERIES TRAINING USE ONLY FUEL SYSTEM 10.12 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface FUEL CONTROL UNIT (MAIN FLOW)

LOW

HIGH TO FUEL PRESSURE Po Po PUMP RELIEF VALVE BYPASS PUMP P2 UNLOADING VALVE P1 PUMP DELIVERY PRESSURE P1 P2 METERED FUEL PRESSURE P1 P0 BYPASS FUEL PRESSURE Po MINIMUM FLOW Py MODIFIED Px FROM FUEL PUMP P2 BYPASS VALVE P2 P1 P2 TO FUEL DISTRIBUTION SYSTEM FUEL Po METERING MINIMUM UNIT PRESSURIZING Py AND SHUTDOWN VALVE Py P2 TO PROPELLER GOVERNOR

PT6A-60 SERIES TRAINING USE ONLY FUEL SYSTEM 10.13 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface FUEL CONTROL UNIT (METERING)

Function: Fuel Valve And Bellows Section:

Determines fuel flow to the engine in response to the follow- The Fuel Valve rotates and moves up and down to deter- ing inputs: mine the amount of fuel going to the engine by varying the - Power Lever Position (PLA) opening between the inner rotating valve and the static - Compressor discharge pressure (P3) outer valve. - Compressor speed (Ng) Cockpit movement of the PLA causes the 3D cam to rotate. Rotation of the 3D cam makes the Cam Follower move 3D Cam And Follower: which in turn rotates the Fuel Valve (Initial accel or decel).

Rotates around it's centerline and up and down in response Up and down movement of the Fuel Valve depends on the to power lever movement and compressor speed (Ng). The bellows position (P3 air pressure). 3D cam is rotated by moving the power lever in the cockpit. The face of the cam is shaped to move the cam follower and - More Wf rotate the fuel valve, thus changing fuel flow and Ng. Increasing P3 moves the Valve Seat down, allowing Pz pressure to diminish, resulting in a downward movement of The 3D cam also senses Ng speed via a flyweight governor. the Fuel Valve. Variation of Ng speed causes the Po orifice to open or close causing the 3D cam to translate up or down. The cam fol- - Less Wf lower and fuel valve move in response to the 3D cam there- Decreasing P3 moves the Valve Seat up, allowing Pz pres- fore changing fuel flow and Ng. sure to increase, resulting in an upward movement of the Fuel Valve.

PT6A-60 SERIES TRAINING USE ONLY FUEL SYSTEM 10.14 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface FUEL METERING SECTION

REASE P1 FROM PUMP INC

POWER LEVER FUEL VALVE P1 3D FOLLOWER Po CAM

FUEL VALVE Pt P2 BLEED TO Po P2 3D CAM FOLLOWERS METERED FUEL OUTLET Pz DRAIN FLYWEIGHT Py GOVERNOR COMPRESSOR NG SPEED P3 SENSOR BELLOWS P1 PUMP DELIVERY SYSTEM RPM P2 METERED FUEL PRESSURE Pt FUEL SERVO PRESSURE Po BYPASS FUEL COMPRESSOR PRESSURE Py GOVERNING AIR PRESSURE P3 COMPRESSOR DISCHARGE PRESSURE P3 Pz FUEL INTERMEDIATE PRESSURE P3 AIR FILTER PSI

PT6A-60 SERIES TRAINING USE ONLY FUEL SYSTEM 10.15 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface METERING SECTION (3D CAM)

INCREASE NG 3D CAM FOLLOWER POWER LEVER FUEL VALVE FOLLOWER

E AS CRE O DE DECREASE NG N WF FOLLOWER SPRING SP E E A D B

WF INCREASE 3D CAM

FLY WEIGHT PT BLEED TO Po FUEL VALVE A- DECEL B- STEADY STATE C- ACCEL D- INTERMEDIARY P3 SENSOR BELLOWS

NG GOVERNOR

PT6A-60 SERIES TRAINING USE ONLY FUEL SYSTEM 10.16 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface FUEL CONTROL SYSTEM

LOW

FUEL CONTROL UNIT (FCU) FUEL PUMP FUEL METERING MAIN FLOW FUEL INLET FUEL CONDITION (FROM FUEL LEVER AND HEATER) PUMP Po Po HIGH HIGH IDLE UNLOADING VALVE CAM P2 PRESSURE RELIEF VALVE Po PUMP P1 P1 3D POWER FUEL VALVE Po LEVER CAM FOLLOWER Po MINIMUM FLOW P2 P1 3D CAM Pt BYPASS VALVE FOLLOWER FUEL P2 Pt BLEED VALVE P1 TO Po Po FLYWEIGHT P2 TO GOVERNOR COMPRESSOR MINIMUM DISTRIBUTION SYSTEM SPEED (NG) DRAIN Pz PRESSURIZING AND P2 Py Py SHUTDOWN VALVE COMPRESSOR P3 P3 AIR FILTER PRESSURE TO (P3) P3 SENSOR BELLOWS PROPELLER GOVERNOR

PT6A-60 SERIES TRAINING USE ONLY FUEL SYSTEM 10.17 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface COMPRESSOR DELEVERY AIR LINES

Function:

To provide clean P3 air to the FCU.

Description:

Compressor discharge air (P3), derived from the diffuser section of the gas generator case, is routed to the metering section of the FCU through external lines and a fine-screen filter. The system consists of two tube assemblies, one on each side of the air filter housing.

Maintenance:

Replace P3 filter - SB’s 13175 and 14054 introduce a P3 air pressure sensitive drain valve to the air filter housing. During compressor wash, P3 air pressure is low, and the valve is spring-loaded open to allow cleaning fluid to drain. As engine speed builds, P3 air pressure increases and closes the valve.

Note: The filter element is normally a permanent (stainless steel) type and is intended to be cleaned ultrasonically at an approved overhaul facility. However, the filter may be cleaned (washed) electronically at field level.

PT6A-60 SERIES TRAINING USE ONLY FUEL SYSTEM 10.18 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface P3 AIR FILTER ELEMENT

P3 AIR FILTER ELEMENT

(POST−SB 13175 & POST-SB 14054)

(PRE−SB 13175 & PRE-SB 14054)

PT6A-60 SERIES TRAINING USE ONLY FUEL SYSTEM 10.19 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface FLOW DIVIDER WITH DUMP VALVE

Function: Operation:

Provides a means to separate the starting flow (primary) When the condition lever is moved to the "fuel on" position, from the normal engine running flow (Pri & Sec). Allows the fuel enters the flow divider and pushes against the primary fuel flow to be ported to a collector can during the shutdown and secondary valve and spring. At a fuel pressure of 9 - (dump) sequence. 13 psi, the primary valve moves to the right and allows fuel to flow to the primary manifold only.

Description: As Ng speed increases, fuel pressure increases (17-22 - Two concentric valves spring loaded to the closed psid) in the flow divider and the secondary valve moves to position the right. At this point, Ng is at approximately 35% and fuel - Fuel pressure operated flows through all the nozzles.

When the fuel lever is moved to the "cut-off" position, the Primary Flow: fuel pressure drops rapidly and the two springs push the primary and the secondary valves toward the closed posi- Allows fuel to flow through primary manifold for starting. Pri- tion. This allows the fuel to drain by gravity into a collector mary valve opens at fuel pressure of 9 - 13 psi can, preventing contamination (carbon deposits) of fuel nozzles due to fuel residue.

Secondary Flow: Maintenance: Combined with the Primary flow, allows enough fuel flow to - No maintenance at field level operate the engine. Secondary valve opens at fuel pressure - Visually inspect for cracks and leaks of 17 - 22 psid.

Dump Position:

Allows fuel to dump into a collector can. Springs move the Primary and Secondary valves to the cut-off position, port- ing both manifolds to dump.

PT6A-60 SERIES TRAINING USE ONLY FUEL SYSTEM 10.20 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface FLOW DIVIDER AND DUMP VALVE

FLOW DIVIDER AND DUMP VA LVE

FUEL NOZZLE COMBUSTION CHAMBER OUTER LINER ASSEMBLY FUEL NOZZLE SHEATH

PRIMARY SECONDARY MANIFOLD PORT MANIFOLD PORT PRIMARY FUEL MANIFOLD GAS GENERATOR CASE

SECONDARY FUEL DUMP FUEL MANIFOLD (To collector can) INLET ADAPTER P2 FUEL IN FUEL FLOW DIVIDER

P2 FUEL IN FUEL DUMP

SECONDARY VALVE PRIMARY VALVE

PRIMARY FUEL MANIFOLD SECONDARY FUEL MANIFOLD DUMP FUEL

PT6A-60 SERIES TRAINING USE ONLY FUEL SYSTEM 10.21 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface FLOW DIVIDER WITH PURGE VALVE

(SB 13074, 14065) Operation: Function: When the fuel lever is moved to the "fuel on" position, fuel enters the flow divider and pushes against the primary and Provides a means to separate the starting flow (primary) secondary valves. from the normal engine running flow (Pri & Sec). Allows the fuel flow to be purged (blown) back to the Combustion At a pressure of 9 - 13 psi, the primary valve moves to the Chamber to be burnt during the shutdown sequence. right and allows fuel to flow in the primary manifold at a pressure providing optimum fuel atomization. Description: - Two concentric valves spring loaded to the closed As Ng speed increases, fuel pressure goes up and at 17 - position 22 psid, the secondary valve moves to the right. At this - A P3 purge check valve separates the fuel side from point, Ng is spooling through 35% and fuel flows through all the air side the nozzles. - Fuel/Air pressure operated When the fuel lever is moved to the cut-off position, fuel Primary Flow: pressure drops and the two springs push the primary and Allows fuel to flow through primary manifold for starting. Pri- secondary valves into the purge position. P3 air, accumu- mary valve opens at fuel pressure of 9 - 13 psi, and forces lated in a purge can, pushes the check valve open and shut the P3 purge check valve. blows the remaining fuel in the manifold and fuel nozzles in the combustion chamber where it is burned. This may Secondary Flow: cause a small Ng and T5 spike during shutdown. Combined with the Primary flow, allows enough fuel flow to operate the engine. Secondary valve opens at fuel pressure Maintenance: of 17 - 22 psid. - No maintenance at field level - Visually inspect for cracks and leaks Purge: - Verify airframe check valves and purge canister. - P3 air accumulator (airframe). - Opens the check valve. - Purges the fuel from transfer tubes and nozzles into the Combustion Chamber.

PT6A-60 SERIES TRAINING USE ONLY FUEL SYSTEM 10.22 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface FLOW DIVIDER AND PURGE VALVE

FUEL NOZZLE COMBUSTION CHAMBER OUTER LINER ASSEMBLY FUEL NOZZLE SHEATH

SECONDARY PRIMARY MANIFOLD PORT MANIFOLD PORT PRIMARY FUEL MANIFOLD GAS GENERATOR CASE

SECONDARY FUEL MANIFOLD P3 AIR INLET ADAPTER FUEL FLOW DIVIDER P2 FUEL IN

PRIMARY FLOW POSITION

SECONDARY VALVE CHECK VALVE PRIMARY VALVE P2 FUEL IN P3 AIR PRIMARY AND SECONDARY FLOW POSITION

PT6A-60 SERIES TRAINING USE ONLY FUEL SYSTEM 10.23 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface SIMPLEX FUEL NOZZLES (A52/60/61, A64, A65)

Function: Maintenance: - Clean or replace nozzles every 400 hours Deliver and atomize metered fuel into the combustion - New operator clean every 200 hours chamber. - Alternate cleaning method, in situ cleaning every 200 hours to extend intervals between removals - Leak test if nozzles tips are removed Construction: - Check for erosion and fretting wear on nozzle sheaths - 14 fuel nozzle adapters, 7 primary, 7 secondary - Upgrades from Simplex to Duplex type nozzles: - 14 sheaths - SB 13182…….A65’s - 14 fuel nozzle tips - SB 14053…….A64 - 28 transfer tubes (manifolds) - SB 14067…….A66/67,A,R,AF

Warning: Operation: Badly Spraying Nozzles Will Reduce Hot Section Compo- On start, fuel flows through the primary manifolds and the nent Life seven primary fuel nozzles. The position of the primary fuel nozzles is such that fuel is sprayed circumferentially towards the spark igniters in order to facilitate ignition.

An increase in Ng causes fuel pressure to increase and the secondary fuel nozzles to spray fuel into the combustion chamber.

During operation, all 14 fuel nozzles receive fuel from the flow divider and deliver it to the combustion chamber.

PT6A-60 SERIES TRAINING USE ONLY FUEL SYSTEM 10.24 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface SIMPLEX FUEL NOZZLES

PRIMARY FUEL MANIFOLD ADAPTER FUEL MANIFOLD ADAPTER

10 20

0 30+ PSI WORKING WORKING TRANSFER TUBE PRESSURE PRESSURE (SECONDARY) 9 PSI 17 PSID FUEL MANIFOLD ADAPTER

TRANSFER TUBE (PRIMARY) TRANSFER TUBE FUEL NOZLE (SECONDARY) SHEATH

PRIMARY FUEL MANIFOLD SECONDARY FUEL MANIFOD TRANSFER TUBE (PRIMARY)

PT6A-60 SERIES TRAINING USE ONLY FUEL SYSTEM 10.25 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface DUPLEX FUEL NOZZLES (A67B/D/F/P AND POST SB FOR OTHERS)

Function: Maintenance: - Clean or replace nozzles every 400 hours. Deliver and atomize metered fuel into the combustion - New operator should clean every 200 hours. chamber. - Alternate cleaning method, in situ cleaning every 200 hours to extend intervals between removals. - Leak test if nozzles tips are removed. Construction: - Check for erosion and fretting wear on nozzle sheaths. - 14 fuel nozzle adapters - 14 fuel nozzle sheaths Warning: - 14 fuel nozzle tips - 28 transfer tubes Badly spraying nozzles will reduce Hot Section component life

Operation:

On start, the flow divider sends fuel to the primary manifolds. The 14 fuel nozzles will deliver fuel to the combustion chamber through the Primary passage.

As Ng increases, the fuel pressure increases. The secondary fuel nozzle passages will spray fuel into the combustion chamber.

During operation, both Primary and Secondary passages of the 14 fuel nozzles receive fuel from the flow divider and deliver it to the combustion chamber.

PT6A-60 SERIES TRAINING USE ONLY FUEL SYSTEM 10.26 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface DUPLEX FUEL NOZZLES

FUEL MANIFOLD ADAPTER

WORKING PRESSURE 10 20 9 PSI + 0 30+ PSI

TRANSFER TUBE (SECONDARY) FUEL MANIFOLD ADAPTER

TRANSFER TUBE (PRIMARY) TRANSFER TUBE FUEL NOZLE (SECONDARY) SHEATH

PRIMARY FUEL MANIFOLD SECONDARY FUEL MANIFOD TRANSFER TUBE (PRIMARY)

PT6A-60 SERIES TRAINING USE ONLY FUEL SYSTEM 10.27 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface FUEL CONTROL UNIT MANUAL OVERRIDE

Function: The P1 to Pz pressure differential will move the fuel valve down to increase fuel flow. Allows the pilot to manually control the FCU fuel valve in the event of a pneumatic (P3, Py) system malfunction. A return spring below the P2 valve ensures the valve follows the bellows movement during normal operation. In the event of a pneumatic failure (P3 or Py), it is easier to com- Installed on the following: press the return spring than the bellows; so less force is - A-60AG required to move the MOR and the Pz valve. - A-64 - A-65AG SB 13196 - A66A, A66D Caution: - A-67B/P - A-67AG Move manual override lever slowly Operation:

In the event of a P3/Py air loss or metering unit malfunction, Maintenance: the pilot can manually control the position of the fuel valve - Operate manual override system regularly to confirm by simulating the action of P3 air pressure. A special lever proper operation and familiarize with engine response is provided in the cockpit to that effect. in this mode

Movement of the Manual Override Lever (MOL) will increase spring pressure on the rate piston, forcing it to move. The rate of movement is established by the orifice which dampens any abrupt MOL movement. The rate piston movement is transmitted to the Manual Override Rod (MOR) that runs through the center of the fuel valve. The MOR forces the P2 valve down allowing Pz pressure to bleed to Po.

PT6A-60 SERIES TRAINING USE ONLY FUEL SYSTEM 10.28 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface FCU MANUAL OVERRIDE

MANUAL OVERRIDE LEVER

RATE PISTON Po

Po MANUAL OVERIDE ORIFICE P2 ROD P1

P3 AIR SPRING Pa P1 PUMP DELIVERY SYSTEM P2 METERED FUEL PRESSURE Pz FUEL INTERMEDIATE PRESSURE Po BYPASS FUEL Py GOVERNING AIR PRESSURE P3 COMPRESSOR DISCHARGE PRESSURE

PT6A-60 SERIES TRAINING USE ONLY FUEL SYSTEM 10.29 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface POWER RECOVERY SYSTEM (PT6-A65R/AR AND 67R ONLY)

Function:

On twin engine aircraft’s, provides manual or automatic power increase on one engine in the event of a severe power loss from the opposite engine.

Description:

A solenoid valve activated by a low torque reading on the failed engine allows P3 air to push on a piston located at the back of the FCU. The piston then rotates an eccentric shaft changing the position of the cam follower on the 3D cam.

The movement of the follower on the cam is designed to cause a rotation of the fuel valve and increases Ng by approximately 4%. The system is used during take-off only.

A P3 bleed to atmosphere allows the servo piston to return when power recovery is selected off (solenoid valve closed).

Maintenance:

Check and adjust Ng increase as per Airframe Maintenance Manual.

PT6A-60 SERIES TRAINING USE ONLY FUEL SYSTEM 10.30 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface POWER RECOVERY SYSTEM

P1 P1 FROM PUMP CAM FOLLOWER FUEL VALVE FOLLOWER

POWER Po LEVER

3D CAM

Po P2 TO FUEL PT NOZZLES Pz FUEL VALVE VALVE SEAT

NG GOVERNOR Py TO BLEED TO PROPELLER ATMOSPHERE DRAIN GOVERNOR SOLENOID VALVE P3 FILTER (AIRFRAME) P3 SENSOR BELLOWS P3 AIR P1 PUMP DELIVERY SYSTEM Py GOVERNINGP2 METERED AIR FUEL PRE PRESSURESSURE Pt FUEL SERVO PRESSURE Pz FUEL INTERMEDIATE PRESSURE Po BYPASS FUEL

P3 COMPRESSOR DISCHARGE PRESSURE

PT6A-60 SERIES TRAINING USE ONLY FUEL SYSTEM 10.31 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface OVERTORQUE LIMITER

Function: A solenoid (deleted by SB 14185) valve is used on the A- 67B and A-67AF to disable the torque limiter when not A back-up unit which prevents engine overtorques. The pilot required. The solenoid valve closes when de-powered. It is always responsible for operating the engine within limits. controls the supply of Py to the torque limiter.

Description: Maintenance: - Adjust unit as per Airframe Maintenance Manual so A oil bellows which senses torquemeter oil pressure and is that the required torque value is not exceeded. linked to a Py bleed orifice. Found on the following engines: - Pressure check unit to ensure Py does not leak. - A-64 - Replace unit if defective. - A-66B/D - A-67AF post SB 14056 - A-67B post SB 14154 - A-67T

Operation:

Oil from the torquemeter chamber passes through a restrictor before entering the bellows. The restrictor dampens torque pressure fluctuation and prevents damage to the bellows assembly. When torque pressure reaches a specified limit above maximum permitted torque, the bellows expands and compresses the spring.

The flapper valve then moves to allow Py air pressure from the fuel control unit to bleed to the atmosphere and therefore limit the fuel supply to the engine.

Bimetallic disks are mounted on the spring to compensate for variation of spring tension caused by change in ambient temperature.

PT6A-60 SERIES TRAINING USE ONLY FUEL SYSTEM 10.32 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface OVERTORQUE LIMITER (A-64, 66A/B/D, 67AF, 67B/R/T)

ADJUSTMENT SCREW

Py AIR FROM FCU

FLAPPER Py AIR VALVE FROM FCU

ADJUSTMENT SCREW BELLOWS TORQUEMETER TORQUEMETER BIMETALLIC OIL PRESSURE DISKS OIL PRESSURE RESTRICTOR

OVERTORQUE NORMAL POSITION POSITION

PT6A-60 SERIES TRAINING USE ONLY FUEL SYSTEM 10.33 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface FUEL CONTROL UNIT ADJUSTMENT

Deadband - Adjust deadband first, by deadband adjustment screw. - Clockwise increases the deadband angle. - Always verify low idle after a deadband adjustment. Low Idle - Always adjust before high idle setting - Loosen FCU lever clamping screw - To increase Ng, loosen top screw, tighten lower one - To decrease Ng, loosen lower screw, tighten top screw - When adjusting Ng, turn screw in increments of 1/6 of a turn at a time High Idle - High idle can be adjusted at two location on the FCU - Adjust at cam follower adjustment screw if there is no stagger in the condition lever. - Adjust High idle stop screw if the condition levers are staggered. - Clockwise rotation increases Ng 1.5% per turn Maximum Ng, - Adjust as per Airframe Maintenance Manual Reverse Ng, Reserve Power

PT6A-60 SERIES TRAINING USE ONLY FUEL SYSTEM 10.34 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface TYPICAL FUEL CONTROL UNIT ADJUSTMENTS

FUEL CONDITION LEVER DEADBAND ADJUSTMENT IF THERE IS MAX Ng STAGGER (FORWARD) FCU LEVER HIGH IDLE STOP POWER LEVER CAM FOLLOWER ADJ. MAX Ng REV (HIGH IDLE) IF NO STAGGER

HIGH IDLE CAM

RESERVE POWER STOP

SPEED RESET SERVO (LOW-IDLE) P3 AIR CUT OFF STOP NG DOWN FOR LOW IDLE ADJUSTMENTPy NG UP

(LOOSEN ONE SIDE AND TIGHTEN OTHER SIDE) {

PT6A-60 SERIES TRAINING USE ONLY FUEL SYSTEM 10.35 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface FUEL SYSTEM TROUBLESHOOTING SUMMARY

Observed Problem Verification Engine Does Not Start / Hot - Ensure that minimum cranking speed is achievable Starts - Verify igniters for proper operation - Check for evidence of fuel flow to the flow divider while motoring the engine - Ensure primary and secondary fuel nozzles are in their respective position (N/A for engines equipped with duplex nozzles) - Replace flow divider - Replace fuel nozzles - Weak batteries Engine Hangs Below Idle - Ensure starting procedure is carried out properly (Hung Start 30-35% Ng) - Flow divider secondary valve not opening Engine Is Slow To Accelerate To - Ensure starting procedure is carried out properly Idle - Check for possible restriction in the P3 air line to the FCU - Possible Py leaks - Replace flow divider - Replace FCU Sub-Idle Condition (40-45% Ng) - P3/Py line leaking or broken. P3 filter blocked - Prop. Governor or Torque Limiter leaking Py. - FCU bellows broken or leaking White Smoke On Shut Down - Verify for proper operation of flow divider and dump/ purge valve From Exhaust Duct - Replace FCU Ng Coupling Failure - Engine will go to 85% power Fuel Leakage Between FCU And - Remove FCU from pump and replace o-ring at fuel bypass port Fuel Pump - Replace FCU and pump if fuel leakage persists

PT6A-60 SERIES TRAINING USE ONLY FUEL SYSTEM 10.36 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface PROPELLER SYSTEM

PROPELLER SYSTEM

PT6A-60 SERIES TRAINING USE ONLY PROPELLER SYSTEM 11.1 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface PROPELLER SYSTEM

Function:

Change the power produced by the engine into thrust in order to propel the aircraft through the air.

Description: - Three to six bladed propellers - Made of Aluminium or Composite materials - Variable pitch, single acting type - Propeller governor (CSU) controls: - Propeller Speed in governing mode. - Blade Angle in Beta mode.

List Of Topics: - Propeller system - Pitch change mechanism - Governing mode - Beta mode - Primary blade angle - Reverse thrust - Feathering - Propeller overspeed governor - Np governor - Propeller governor adjustments

PT6A-60 SERIES TRAINING USE ONLY PROPELLER SYSTEM 11.2 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface PROPELLER SYSTEM

PROPELLER BLADE

PROPELLER PITCH CHANGE GOVERNOR MECHANISM

SPINNER

PT6A-60 SERIES TRAINING USE ONLY PROPELLER SYSTEM 11.3 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface PITCH CHANGE MECHANISM

Function: When oil pressure is decreased, the return spring and counter weights force the oil out of the servo piston and Allow varying the propeller blade angle in order to maintain change the blade pitch to a coarser position. a constant Np through various ambient conditions and power settings. An increase in oil pressure drives the blades towards a finer pitch.

Description: - Hollow spider hub supports the blades CSU Action Propeller Reaction Max Position - Feathering spring attached to the servo piston (dome) - Centrifugal counterweights on each blade working with Oil In Finer Pitch Reverse the feathering spring drive the propeller blade toward (lower pitch) feather (faster prop RPM) - Oil pressure from the propeller governor drives the propeller towards reverse position Oil Out Coarser Pitch Feather (higher pitch) (slower prop RPM) Operation:

Oil from the propeller governor feeds into the propeller shaft Maintenance: and to the servo piston via the oil transfer sleeve mounted - Refer to the Airframe Maintenance Manual. on the propeller shaft.

As oil pressure increases, the servo piston is pushed forward and the feather spring is compressed. Servo piston movement is transmitted to the propeller blade collars via a system of levers.

PT6A-60 SERIES TRAINING USE ONLY PROPELLER SYSTEM 11.4 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface PITCH CHANGE MECHANISM

PROPELLER PROPELLER GOVERNOR (CSU) MOVES FORWARD FROM PBA TO REV SPIDER HUB

SERVO PISTON (DOME)

OIL TRANSFER SLEEVE FEATHERING SPRING

BLADE ACTUATING LEVER

PT6A-60 SERIES TRAINING USE ONLY PROPELLER SYSTEM 11.5 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface PROPELLER GOVERNOR GOVERNING MODE

Description: Speeder Spring: - Opposes a mechanical force to the centrifugal force of Is the range of operation where engine power is sufficient to the flyweights maintain the selected propeller speed by varying the blade - Determines the propeller speed at which the flyweights angle (pitch). will be "on speed." - The pilot controls spring tension through the propeller The System Is In The Governing Mode When: lever (not on A-67B/P). - Indicated propeller speed matches selected NP. - increase in Ng speed do not affect Np. Operation: - Moving the propeller lever results in a change in Np Oil is supplied to the governor. A gear pump, mounted at the base of the governor, increases the flow of oil going to Components: the CSU relief valve. When the oil pressure reaches the desired level, the relief valve opens to maintain the pres- Pressure Relief Valve: sure. - Opens to bypass oil when maximum pressure is When the speed selected by the pilot is reached, the fly- reached (450 to 720 depending on the model) weights force equals the spring tension of the speeder spring. The governor flyweights are then on speed. Pump Gears: When the engine output power is increased, the power tur- - Supply oil pressure to control the propeller pitch bines tend to speed up. The flyweights in the CSU sense this acceleration. The flyweights go into an overspeed con- Governor Flyweights: dition because of the increase centrifugal force and force - Rotation of the flyweights generate a centrifugal force the control valve to move up and restrict oil flow to the pro- proportional to the propeller speed peller dome. The feathering spring increases the propeller - Flyweight force pushes against a spring to move the pitch to maintain the selected speed. Reducing power control valve up or down causes an under-speed of the flyweights, downward movement of the control valve, more oil in propeller dome, result- Pilot Valve: ing in a finer pitch to control propeller speed. - Moves up and down under the influence of the fly- The propeller governor houses an electro-magnetic coil, weights which is used to match the rpm of both propellers during - Controls the oil pressure going to the propeller cruise. An aircraft supplied synchro-phaser unit controls this function.

PT6A-60 SERIES TRAINING USE ONLY PROPELLER SYSTEM 11.6 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface GOVERNING MODE

NO MOVEMENT

PROPELLER SPEEDPRESSURE CONTROL LEVERRELIEF BETA Py RESET POST VALVE VALVE GOVERNOR LEVER SPRING SHUT-OFF (LOCK PITCH) SOLENOID VALVE RESET ARM PT6A-67B/P NO MOVEMENT WITH FIXED PROPELLER SPEED MIN. GOV. ADJ.ENGINE CSU PUMP BETA OIL VALVE PILOT VALVE CARBON BLOCK NO MOVEMENT

BETA ROD SUPPLY PRESSURE HYDRAULIC RETURN TO PUMP LOW PITCH ADJ. PROPELLER SERVO PRESSURE

PT6A-60 SERIES TRAINING USE ONLY PROPELLER SYSTEM 11.7 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface PROPELLER GOVERNOR

BETA MODE (FORWARD OPERATION) Power Lever:

Description: On the ground, movement of the power lever below the idle gate causes the reversing cam to actuate the beta valve, The beta mode corresponds to a range of operation where thus causing the blade angle to reduce the blade angle is between PBA (Primary Blade Angle) and reverse. The propeller pitch is a direct function of the beta valve position (power lever) Operation: At low power, the propeller and governor flyweights do not turn fast enough to compress the speeder spring. In this Function: condition, the control valve moves down and high pressure - Prevents the blade angle from going below minimum in oil pushes the dome forward, moving the blades towards a flight (Primary Blade Angle, PBA) finer pitch. - Allows the pilot to manually control the blade angle on The propeller dome in it's forward movement contacts the the ground for taxiing and reverse operation beta nuts. Any further movement pulls the beta rod and the slip ring forward. The forward motion of the slip ring is transmitted to the beta valve via the beta lever and the car- You Are In The Beta Mode When: bon block. Forward movement of the beta valve stops the - Indicated Np is below selected Np oil supply to the propeller. This prevents the blade angles - A change in Ng speed causes a Np change from going any finer. This is called "Primary Blade Angle" - Propeller lever movement does not change Np (PBA) and it is the minimum blade angle allowed for flight operation.

Beta Feedback System: From this point the propeller is in the beta mode. If the engine power is reduced when the propeller is at the pri- In low pitch operation, the beta nuts, beta rods, slip ring, mary blade angle, the propeller speed will decrease since carbon block and the beta lever, which compose the beta the blade angle does not change. feedback system, actuate the beta valve

PT6A-60 SERIES TRAINING USE ONLY PROPELLER SYSTEM 11.8 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface BETA MODE (FORWARD OPERATION)

NO MOVEMENT

PROPELLER SPEED CONTROL LEVER BETA RESET POST VALVE GOVERNOR LEVER SPRING Py SHUT-OFF (LOCK PITCH) SOLENOID VALVE RESET ARM MOVES IN RESPONSE TO MIN. GOV. BETA FEEDBACK RING ADJ. BETA VALVE PILOT VALVE CARBON ENGINE CSU PUMP OIL BLOCK

BETA ROD SUPPLY PRESSURE BETA FEEDBACK RING MOVES FORWARD AS RETURN TO PUMP ≈ HYDRAULIC PROP REACHES 10˚ LOW PITCH ADJ. PROPELLER SERVO PRESSURE

PT6A-60 SERIES TRAINING USE ONLY PROPELLER SYSTEM 11.9 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface PROPELLER GOVERNOR (CONT’D)

Lockpitch Solenoid Valve: Prevents the propeller from going into reverse or below the primary blade angle in the event of a Beta system malfunction in flight. The solenoid is energized by a switch (airframe supplied) mechanically connected to the propeller slip-ring linkage via a second carbon block. Any movement of the slip ring towards reverse blade angle, prior to the pilot selecting reverse, energizes the solenoid and stops the oil flow from the governor pump to the propeller servo. This controls the blade angle from going any finer.

As oil pressure leaks off around the propeller shaft oil transfer sleeve, the blade angle slowly drifts back toward coarse pitch. This will de-activate the low pitch solenoid valve and restore the oil supply to the propeller servo. The low pitch solenoid valve will cycle (close/open) as back-up to the beta valve function.

PT6A-60 SERIES TRAINING USE ONLY PROPELLER SYSTEM 11.10 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface BLANK PAGE

PT6A-60 SERIES TRAINING USE ONLY PROPELLER SYSTEM 11.11 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface PROPELLER GOVERNOR

BETA MODE (REVERSE OPERATION) As Np increases due to the increase in engine power, the governor flyweights begin to move outwards. Since the Function: reset lever is closer to the speeder spring cup, the cup contacts the reset lever before the flyweights would normally Allows the pilot to control the propeller with a negative blade reach the on-speed position (95% Np instead of 100%). angle. (Reverse thrust). When the reset lever is pushed up by the flyweights/ speeder spring cup, Py bleeds from the Fuel Control Unit (FCU) which lowers the Wf, engine power and thus propel- Operation: ler speed.

Moving the power lever backwards causes the reversing In reverse Np remains 5% below the selected propeller cam and cable to move the beta valve backward, allowing speed so that the control valve remains fully open and only more oil to flow into the propeller dome, causing the blades the beta valve controls the oil flow to the propeller dome. to go towards reverse pitch. In this mode, the propeller speed is no longer controlled by As the blades move to reverse, the slip ring is pulled forward changing the blade angle ( i.e.: servo pressure). It is now by the dome (beta nuts) and moves the beta valve outward controlled by limiting engine power (i.e.: Ng speed). restricting the oil flow. This stops the blade movement toward reverse. To obtain more reverse thrust, the power lever must be moved back more to reset the beta valve inward and repeat the process.

The reset arm on the CSU is moved rearward by the interconnecting rod at the same time as the blade angle is moving toward reverse. This causes the reset lever and reset post to move down in the CSU. This brings the reset lever closer to the speeder spring cup.

PT6A-60 SERIES TRAINING USE ONLY PROPELLER SYSTEM 11.12 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface BETA MODE (REVERSE OPERATION)

REVERSING CAM PUSH-PULL CONTROL REARWARD MOVEMENT

PROPELLER SPEED CONTROL LEVER BETA VALVE LEVER RESET POST GOVERNOR SPRING SHUT-OFF (LOCK PITCH) Py SOLENOID VALVE

RESET ARM

REARWARD MOVEMENT UNDERSPEED FCU ECCENTRIC BETA ARM VALVE SCREW PILOT VALVE CARBON CSU PUMP BLOCK ENGINE OIL

SUPPLY PRESSURE RETURN TO PUMP BETA ROD

PROPELLER SERVO PRESSURE HYDRAULIC LOW PITCH ADJ.

FULL FWD POSITION

PT6A-60 SERIES TRAINING USE ONLY PROPELLER SYSTEM 11.13 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface PROPELLER FEATHERING

Function: Maintenance:

Minimise propeller drag by streamlining the blades in the Check feathering operation as per Airframe Maintenance event of an in-flight engine shutdown. Manual instruction.

Adjustment: Description: Adj. Feather screw CW -> Increases the time to feather Bringing the propeller lever to the feather position causes Adj. Feather screw CCW->Decreases the time to feather the speed selection lever on the CSU to push the feathering valve plunger and allows propeller servo oil to dump into the reduction gearbox sump.

The pressure loss in the propeller hub causes the feathering spring and the propeller counterweights to feather the propeller quickly.

Note: The A-67B/P propeller governor has no provision for speed control. Feathering is done through a feather solenoid located on the propeller overspeed governor.

The A-64 propeller governor has no feathering valve. Feathering is done through physically lifting the control valve by rotating propeller speed actuating lever completely CCW.

PT6A-60 SERIES TRAINING USE ONLY PROPELLER SYSTEM 11.14 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface PROPELLER FEATHERING

FEATHERING VALVE SPEEDER SPRING ACTUATING LEVER

GOVERNOR SPRING Py

FEATHERING TO SUMP PLUNGER

CARBON BLOCK TO SUMP

PILOT VALVE

BETA ROD

HYDRAULIC GOVERNOR OIL PRESSURE LOW PITCH ADJ. BYPASS TO PUMP PROPELLER SERVO PRESSURE

PT6A-60 SERIES TRAINING USE ONLY PROPELLER SYSTEM 11.15 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface NF GOVERNOR (OVERSPEED PROTECTION)

Description: The movement of the reset lever around its pivot point opens the Py air passage. Py bleeds into the reduction The CSU contains a Py bleed orifice closed by a ‘flapper’ gearbox limiting the fuel supply to the engine. This will pre- valve and reset lever. The ‘flapper’ valve/reset lever can be vent the propeller/power turbines from accelerating beyond opened by the speeder spring cup when the flyweights 106%. react to an increase in centrifugal force caused by an overspeed of the propeller/power turbines. Maintenance: - Adjust speed limit in reverse using the underspeed In Forward Propeller Operation: eccentric screw (max rev screw). - Over-speed limit adjustment in forward propeller oper- Provides Np overspeed protection (6% above selected ation is not permitted. prop speed) by bleeding-off Py air pressure from the FCU - Check for Py leakage which will cause a loss of perfor- thus reducing the power of the engine. mance.

In Reverse Propeller Operation:

Limits propeller speed to a value approximately 5% below the selected Np by bleeding-off Py air pressure from the FCU thus reducing the power of the engine.

Operation:

In the event of a propeller overspeed not controlled by the propeller overspeed governor (oil governor), the flyweights in the propeller governor will move outwards until the speeder spring cup contacts the reset lever.

PT6A-60 SERIES TRAINING USE ONLY PROPELLER SYSTEM 11.16 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface NF GOVERNOR

SPEEDER SPRING CUP

FLYWEIGHTS RESET LEVER

Py SEAL

AIR BLEED ORIFICE

PIVOT

Py AIR FROM FCU TO SUMP OIL TO RGB PROPELLER SERVO OIL

PT6A-60 SERIES TRAINING USE ONLY PROPELLER SYSTEM 11.17 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface PROPELLER OVERSPEED GOVERNOR

(AIRFRAME OPTION) increase in blade pitch puts more load on the engine and slows down the propeller. Function: To test the unit, the speed reset solenoid is activated and Provides back up protection against propeller and power servo oil pressure pushes against the reset piston to cancel turbine over speeds (4% over max prop speed). the effect of the reset spring. With less spring tension acting on the flyweights, the overspeed governor can be tested at speeds lower than maximum. Description: - Airframe supplied except on A-67B/P On twin installation, a second solenoid valve is mounted on - Flyweight governor actuating a control valve the overspeed governor and is used in conjunction with the - One solenoid valve to reset the unit during ground aircraft auto-feather system. The system is switched on for tests take off and in the event of an engine malfunction will ener- - One solenoid to feather the propeller gize the solenoid valve to dump propeller servo oil into the reduction gearbox sump. The feathering spring and propel- On the PT6A-67B, the overspeed governor feather solenoid ler counter-weights move the blade quickly to feather. is the only way to feather the propeller and the speed reset solenoid is replaced with a mechanical reset lever mounted on the governor. Maintenance: - Test the unit on a regular basis. - With the reset solenoid energized, verify the speed at Operation: which the overspeed governor controls Np. - A67B/P: No solenoid, rotate mechanical reset The governor houses a set of flyweight connected to a con- lever to test trol valve that is driven by a bevel gear mounted on the pro- - Refer to the Airframe Maintenance Manual for adjust- peller shaft. The flyweight's centrifugal force is acting ment. against two springs, a speeder spring and a reset spring.

When the propeller speed reaches a specified limit (4% over maximum Np) the governor flyweights lift the control valve and bleed off propeller servo oil into the reduction gearbox sump, causing the blade angle to increase. An

PT6A-60 SERIES TRAINING USE ONLY PROPELLER SYSTEM 11.18 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface PROPELLER OVERSPEED GOVERNOR

(AIRFRAME)

SPEED ADJUSTING RESET SPRING REDUCES SPRING TENSION = LOWER O/S SCREW RESET PISTON

SPEEDER SPRING

FLYWEIGHTS

SPEED RESET SOLENOID SPEED RESET OIL ACTIVATION

GOVERNOR SPLINE DRIVE

FEATHERING SOLENOID VALVE

FROM CSU

PT6A-60 SERIES TRAINING USE ONLY PROPELLER SYSTEM 11.19 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface NOTES

PT6A-60 SERIES TRAINING USE ONLY PROPELLER SYSTEM 11.20 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface PROPELLER OVERSPEED GOVERNOR PT6A-67B

OIL OUT FROM FEATHERING VALVE Py TO FCU ISOLATING SOLENOID VALVE

TQ LIMITER

PROPELLER OVERSPEED GOVERNOR (A-67B/P ONLY)

PT6A-60 SERIES TRAINING USE ONLY PROPELLER SYSTEM 11.21 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface PROPELLER GOVERNOR ADJUSTMENTS

Maximum - Set propeller lever at maximum position in the cockpit Forward - Ensure that max Np stop is contacted Propeller - Adjust screw CCW to increase maximum Np, CW to decrease. Speed (Np) - One flat alter Np 2% (A-67R/AF/AG), 4% (A-67/67A) Maximum - Set propeller lever at maximum Np position Reverse - Disconnect reset arm from interconnect rod Propeller - Secure reset arm against rear stop Speed - Move power lever forward until propeller speed stabilises - Check that propeller speed stabilises within specified limits - Adjust underspeed eccentric screw if required - In some cases the FCU may not be adjusted to provide enough reverse power, this requires an initial check/adjustment of the FCU before adjusting the CSU Feathering Operation - Set power lever at ground idle Check - Move propeller lever to the feather position note feathering time, adj. as req.

PT6A-60 SERIES TRAINING USE ONLY PROPELLER SYSTEM 11.22 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface PROPELLER GOVERNOR ADJUSTMENT

FEATHERING TIME RESET ARM MAX. STOP A67B/P ADJUSTMENT DO NOT ADJUST

FRONT CLEVIS

TO CAM BOX

MAX PROP SPEED (FORWARD) BETA LEVER BETA VALVE CAP NUT UNDERSPEED ECCENTRIC SCREW (MAX REVERSE Np) RIG FLUSH

INTERCONNECT ROD

CLEVIS

VALVE BETA VALVE

PT6A-60 SERIES TRAINING USE ONLY PROPELLER SYSTEM 11.23 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface PRIMARY BLADE ANGLE (PBA) CHECK

Function: Troubleshooting: - Indicated torque lower than target = PBA too fine Provide equal flight idle torques for appropriate aircraft han- - Indicated torque higher than target = PBA too coarse dling. On twin engine applications the aircraft may yaw if PBA is not the same on both engines. On single engine air- Adjust the beta valve position by adjusting the reversing craft, approach handling characteristics are dependant on cable clevis end PBA. - Move clevis end forward to increase torque - Move clevis end rearward to decrease torque Procedure:* - Record OAT Adjust beta nuts as per airframe manual to rectify - Record field barometric pressure - Move beta nuts rearward to increase torque - Set propeller lever at maximum position - Move beta nuts forward to decrease torque - Increase power until target Np is reached - Target Np speed is always less than maximum speed Note: to ensure the beta valve is actuated Some airframe or propeller manufacturers do not - Stabilise engine and record torque allow adjusting the beta nuts . The only option left is to - Compare indicated torque with torque given by chart in adjust the beta valve inwards only . This will give a finer Airframe Maintenance Manual PBA on the higher indicating engine .

*(For reference only, refer to aircraft maintenance manual for specific procedure)

PT6A-60 SERIES TRAINING USE ONLY PROPELLER SYSTEM 11.24 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface PRIMARY BLADE ANGLE CHART - 4000 - 2000 0 2000 4000 6000 8000 10000 12000

40 PRESSURE ALTITUDE IN FEET 30

OAT °C 0

-10

-20

-30

-40 900 600

300 0

PROPELLER TORQUE IN FT-LBS PROPELLER SPEED 1500 RPM

PT6A-60 SERIES TRAINING USE ONLY PROPELLER SYSTEM 11.25 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface PROPELLER SYSTEM TROUBLESHOOTING

Observed Problem Action Required Np And Torque Fluctuations At High Max Np setting may be too high (interference with OSG) Power Overspeed governor test solenoid leaking. (interferes with prop.Governor) (No Ng Fluctuation) Np And Torque Fluctuation At Low Verify Beta ring is not distorted Power Inspect carbon block for excessive wear (In Beta) Check beta nut adjustment (not equal) Propeller Slow To Unfeather Carbon block worn out or beta valve rigged too far out Low servo pressure from prop. governor Np, Tq And Ng Fluctuation Ensure reset arm is positively sitting against forward stop (Power Fluctuation) Verify Py line for leaks Replace FCU if problem is still present Propeller Rpm Too High (Governing) Check propeller speed gauge for accuracy Adjust maximum stop on governor Replace prop. governor if adjustment is not effective Propeller Rpm Too Low (Governing) Insure max stop is contacted Adjust maximum stop on governor Ensure Ng is not limited by any P3 or Py leak. Replace propeller governor Check/Replace overspeed governor Propeller Rpm Too Low Check Nf governor minimum adjustment in reverse (Reverse) Adjust FCU maximum reverse Ng stop Propeller Rpm Too High Check that maximum forward propeller speed is OK (Reverse) Check proper rigging of the reset arm. May not be bleeding enough Py Check Nf governor minimum adjustment in reverse

PT6A-60 SERIES TRAINING USE ONLY PROPELLER SYSTEM 11.26 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface MAINTENANCE PRACTICES

MAINTENANCE PRACTICES

PT6A-60 SERIES TRAINING USE ONLY MAINTENANCE PRACTICES 12.1 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface PERIODIC INSPECTION

The following table is for reference only, refer to your Engine Maintenance Manual. FREQUENCY COMPONENTS

Routine : coincides with daily or pre-flight airframe inspec- 25 hours 2nd Power Turbine Blades tion. 50 hours 2nd Stage PT Blades Minor : coincides with a typical airframe inspection. 100 hours Engine Oil Notes: Oil Filter Element 1)The intervals at which these inspections are performed may be altered by the aircraft manufacturer’s AGB Drive maintenance program and approved by the opera- P3 Air Filter tor’s local airworthiness authority. 2)Engines operating in sandy or dusty environments or P3 Air Filter Drain Valve in smog or salt-laden atmospheres should be sub- jected to additional inspections for corrosion and Chip Detector compressor erosion. 125 hours 2nd Power Turbine Blades Minor Control Linkage FREQUENCY COMPONENTS Fuel Control Unit Routine Oil Level Manual Override FCU Oil Filler Cap Fuel Pump Fuel System Fuel Pump Outlet Filter Fuel & Oil Lines Oil-to Fuel Heater Scavenge Oil Pump Housing P3 Air Filter Propeller Oil Shaft Seal P3 Air Filter Bowl Accessories Oil Filter Element

PT6A-60 SERIES TRAINING USE ONLY MAINTENANCE PRACTICES 12.2 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface PERIODIC INSPECTION (CON’T)

FREQUENCY COMPONENTS FREQUENCY COMPONENTS

Minor Tubing, Wiring & Hoses 250 hours 2nd Power Turbine Blades (Oil/Fuel/P3/Py) 300 hours Fuel Pump Inlet Screen Ignition Exciter Oil Filter Ignition Cables 400 or 600 hours Fuel Manifold Adapter & Sparks Igniters Nozzle Assemblies Accessories 600 hours Sundstrand Fuel Pump only Air Inlet Screen Fuel Pump Inlet Screen Air Inlet Case Fuel Pump Outlet Filter Gas Generator Case 600 hours or 12 months Chip Detector Fireseal Mount Rings 1,000 hours Oil Filter Drain Valves Agb Scavenge Pump Filter Flow Divider P3 Air Filter Exhaust Duct At component Accessory Gearshaft Spline Replacement / Removal 200 hours 2nd Power Turbine Blades

Fuel Manifold Adapter & Nozzle Assemblies 200 hours or 6 months AGB Scavenge Pump Filter 200 or 400 hours Fuel Manifold Adapter & Nozzle Assemblies

PT6A-60 SERIES TRAINING USE ONLY MAINTENANCE PRACTICES 12.3 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface HOT SECTION INSPECTION

Purpose: HSI Frequency: - As per relevant SB To optimize engine performance, fuel economy, safety and - On condition (as per ECTM result) increase components life. The condition of the hot section parts has a direct effect on engine performance. Deteriora- Pre HSI Actions: tion of the hot section can be detected by using engine condition trend monitoring (ECTM) and / or by doing 1. Do a performance check. The result of the performance performance checks (refer to chapter 9). check will be compared with a post HSI check to monitor performance recovery. Deterioration of hot section components may include crack- 2. Remove and inspect oil filter, magnetic chip detector and ing, burning, buckling, erosion, fretting wear and corrosion. RGB strainer for metal contamination. 3. Remove air inlet screen and inspect first stage compres- Hot section distresses is usually attributed to malfunctioning sor blades for F.O.D. fuel nozzles, hot starts, running the engine beyond acceptable ITT limits, continuous operation at maximum power, Return engine to an overhaul facility if #2 check is beyond doing rapid accelerations, or abusing reverse thrust or FOD. limits.

Engine Disassembly: Goals Of The HSI Include: - Remove power section - Maintaining CT blade tip clearance close to a minimum - Measure Compressor Turbine blade tip clearance - Optimizing lug to slot fits on CT vane - Remove Compressor Turbine assembly - Minimizing P3 air leaks, internal or external - Remove fuel nozzles - Ensuring that replacement compressor turbine vane - Remove spark igniters ring and power turbine vane ring classes are kept the - Remove combustion chamber liners same as installed during the last test-cell run. - Remove CT vane assemble - Remove large exit duct

PT6A-60 SERIES TRAINING USE ONLY MAINTENANCE PRACTICES 12.4 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface NOTES

PT6A-60 SERIES TRAINING USE ONLY MAINTENANCE PRACTICES 12.5 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface BORESCOPE INSPECTION

Description: Procedure: - Remove one fuel manifold adapter. The borescope inspection allows operators to visually - Insert the guide tube through the open port. inspect hot section components without disassembling the - Install the holding fixture to the engine "C" flange. engine. - Connect the borescope to the light source. - Insert the borescope into the guide tube with care.

The following components can be inspected with a bores- Note: cope: Keep in mind that you are looking 125 degrees away from - Compressor turbine blades. the point of entry of the tip as shown in the figure. - Leading and trailing edges of compressor turbine vane ring. Inner and outer walls of vane rings. All compressor turbine blades can be inspected through - All CT vanes can be inspected when fuel nozzles are one fuel nozzle adapter port. Using the proper tool in the removed for inspection. starter drive can rotate the compressor. Ensure borescope - Turbine shroud segments. tip does not interfere with compressor turbine blades. - Cooling rings and dome section of the combustion chamber. The guide tube is not required for the inspection of combustion chamber liner.

Use the borescope with care since it is a very fragile device. A 35-mm, digital or a video camera may be mounted on the viewer to record inspection of hot section areas (adapters required). Engine must be cool prior to using the borescope. Cool down engine for a minimum of 40 minutes.

PT6A-60 SERIES TRAINING USE ONLY MAINTENANCE PRACTICES 12.6 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface GUIDE TUBE ORIENTATION

FUEL MANIFOLD ADAPTER PORT

RIGID GUIDE TUBE

POINT OF ENTRY (REF.)

FIBERSCOPE TIP 125 VANE RING

DISTAL POINT

RELATION BETWEEN POINT OF ENTRY AND DISTAL TIP

VIEW FROM EXHAUST DUCT TOWARD AIR INLET CASE

PT6A-60 SERIES TRAINING USE ONLY MAINTENANCE PRACTICES 12.7 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface HOT SECTION TOOLS

1. Power Section Sling (Without The Propeller Installed On The Engine) (PWC34673). 2. Compressor Turbine Holding Wrench (PWC30331). 3. Spacers (4) (PWC34478). 4. Spreader (PWC30335). 5. Compressor Turbine Puller (PWC30403). 6. Protector Sleeve (PWC30336). 7. Puller No. 2 Bearing Cover (PWC32823). 8. Dial Indicator (PWC 32280). 9. Shroud Grinder Adapter (PWC 32209). 10. Fuel Nozzle (PWC32811). 11. Grinder (PWC37918). 12. Crimper (PWC30458).

PT6A-60 SERIES TRAINING USE ONLY MAINTENANCE PRACTICES 12.8 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface HOT SECTION TOOLS

7 2 10 4

5 6 3 8

9 1 11 12

PT6A-60 SERIES TRAINING USE ONLY MAINTENANCE PRACTICES 12.9 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface CT TIP CLEARANCE MEASUREMENT

Procedure: - Measure tip clearance using a tapered or a wire feeler gage, loading the CT disk in the direction of the measurement. - The tip clearance limits for each individual model is listed in the Engine Maintenance Manual. - No need to rotate turbine while taking measurements.

Limits Shown In The Maintenance Manual: - Average clearance for new segments. - Average clearance for used segment (that ran at least 5 minutes at take off power).

Amount Of Readings Taken: - Average all readings and compare with limits stated in Engine Maintenance Manual. - For 10 segment types, take 3 readings per segment. (3 readings x 10 segments = 30 readings). - For 20 segment types, take 2 readings per segment. (2 readings X 20 segments = 40 readings)

PT6A-60 SERIES TRAINING USE ONLY MAINTENANCE PRACTICES 12.10 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface NOTES

PT6A-60 SERIES TRAINING USE ONLY MAINTENANCE PRACTICES 12.11 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface HOT SECTION INSPECTION (CONT’D)

Inspection CT Vane: - Inspect vane ring for evidence of burning, cracking and Gas Generator Case: coating loss. - Inspect case for cracks, distortion, corrosion and evi- - Insure proper sliding fit (lugs to slots) with mating dence of overheating. parts. - Inspect engine mount threads. - Check air-cooling holes for blockage. - Inspect P3 air supply holes at CT vane flange for - Change ‘C’ & ‘W’ seal rings. blockage. - Inspect diffuser pipes for cracks and fretting wear. - Inspect shanknuts at CT vane flange for security. Shroud Housing: - Inspect shroud housing for cracks, blockage of cooling air holes, fretting wear at sealing ring contact area Combustion Chamber Liners: - Visually inspect the liners for evidence of burning, cracking, buckling or metal to metal fretting wear. Shroud Segments: - Regap cooling rings if they are distorted. - Inspect shroud segments for cracks, burning distortion - Stop drilling of cracks and welding may be required and metal buildup (refer M/M for limits). - Tip clearance

Small Exit Duct: Compressor Turbine: - Inspect for evidence of burning, cracking, buckling, - Inspect CT blades for: tip rub, cracks, sulphidation, coating loss or metal to metal fretting wear. erosion, burning and coating loss. - Stop drilling of cracks may be required (refer M/M for - Inspect CT disk for damage. limits) - Wash turbine blades based on past sulphidation experience.

PT6A-60 SERIES TRAINING USE ONLY MAINTENANCE PRACTICES 12.12 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface CT BLADE SULPHIDATION

STAGE 1 - MILD SULPHIDATION STAGE 2 - OXIDE FAILURE

EVIDENT SLIGHT ROUGHNESS OF SURFACE ROUGHNESS OF SURFACE IS MORE EVIDENT DUE TO SOME GROWTH AND BREAK DOWN AS BREAKDOWN OF THE OXIDE SCALE LAYER OF THE OXIDE LAYER. CONTINUES. DEPLETION OF CHROMIUM FROM DEPLETION OF CHROMIUM HAS NOT STARTED. UNDERLYING ALLOY HAS STARTED. MECHANICAL INTEGRITY IS NOT AFFECTED MECHANICAL INTEGRITY STILL NOT AFFECTED.

STAGE 3 - SEVERE SULPHIDATION STAGE 4 - CATASTROPHIC ATTACK

OXIDATION OF THE BASE MATERIAL HAS DEEP PENETRATION OF SULPHIDATIONK ATTAC PENETRATED TO SIGNICANT DEPTH. WITH LARGE BLISTER OF SCALE. LOSS OF BUILD-UP OF BLISTER SCALE STRUCTURAL MATERIAL LIKELY TO RESULT NOTICEABLE. MECHANICAL INTEGRITY IN BLADE FRACTURE. SERIOUSLY AFFECTED.

PT6A-60 SERIES TRAINING USE ONLY MAINTENANCE PRACTICES 12.13 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface HOT SECTION INSPECTION (CONT’D)

Inter-Stage Sealing Ring: Sealing surface restoration - Inspect sealing ring(s) for fretting wear on sealing diameter and face. Purpose: - Fit ring on sealing diameter for full contact. To achieve best sealing of P3 in the gas generator case area and keep leakage to a minimum. Power Turbine Vane: - Inspect vane ring for evidence of burning, cracking and coating loss. Description: - Ensure proper sliding fit (lugs to slots) with PT stator There are 2 sealing surface contacts that must be checked housing. for proper seating: - Damage to the power turbine vane ring is not common unless bad fuel nozzles caused damage to CT area. 1. Lock-plate to vane ring inner diameter. 2. Vane ring outer diameter to small exit duct.

Power Turbines: Gas tight contact between these surfaces, depends on sur- - Inspect the 1st and 2nd stage power turbines for: face finish and flatness. Surface finish should be better than cracks, burning, coating loss, corrosion, and impact 32 micro-inches and .0005" max waviness. Lapping can be damage and blade shift. used to eliminate minor surface imperfections. When lap- - Return the power section to an authorized overhaul ping is impractical, the assemblies should be machined at facility if either turbine needs to be replaced. an approved overhaul facility.

Exhaust Case: - Inspect the case for general condition. - Check the case for cracks near the flanges. - Inspect flange -D- area for cracks around PT shroud.

PT6A-60 SERIES TRAINING USE ONLY MAINTENANCE PRACTICES 12.14 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface HOT SECTION INSPECTION (CONT’D)

Fitting Of Hot Section Parts Step 2:

Purpose: Install the shroud housing on a bench with the slots upper- - To achieve best fitting of the hot section parts for mini- most. Install the vane ring lugs inside the shroud housing mizing side play which can result in CT tip rub. lugs. - To allow thermal expansion to take place, without any binding. Rotate the vane in the direction it would want to turn, as the gases flow through it. Hold the shroud housing still. This will force the lugs to contact the slots on one side and to Description: have a loose fit on the other side. Measure clearance on both sides with a narrow feeler gage, ref. MM for limits. There are 2 lug to slot fit areas that must be checked for proper fit: If clearance cannot be achieved, re-index the parts and measure. If clearance can still not be obtained, remove 1. Vane ring inner lugs to #2 bearing cover slots. material lightly with a stone until fit is achieved. 2. Vane ring outer lugs to shroud housing slots.

Step 1:

Install the vane ring on a bench with the inner lugs upper- most. Install the #2 bearing cover slots around the vane ring lugs.

Rotate the vane in the direction it would want to turn, as the gas flow through it. Hold the #2 bearing cover still. This will force the lugs to contact the slots on one side and to have a loose fit on the other side. Measure clearance on both sides with a narrow feeler gage, ref. MM for limits.

PT6A-60 SERIES TRAINING USE ONLY MAINTENANCE PRACTICES 12.15 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface HOT SECTION INSPECTION (CONT’D)

Shroud Segment Grinding Preparations: - Mask vane ring, #2 bearing and gas generator area To achieve optimum Compressor Turbine tip clearance all carefully. around the shroud. - Install the 4 rubber spacers with equal tension between the large and small exit ducts. - Install the grinder adapter on compressor stub shaft. Hot Section Kit: - Install the radius gage on the adapter and calculate the tip clearance. Operators who are equipped with the proper tooling can do their own grinding. The preferred method is to send the hot section kit to an approved P&WC service center, which can Calculating Amount Of Metal Removed By Grinding achieve a superior surface finish and concentricity control. The hot section kit consists of the following: The shroud inside dimension (radius) is measured by - CT vane assembly (vane ring, small exit duct, shroud comparing reference master tool to the shroud dimension. housing and segments. - #2 bearing cover and / or flange. The dimension stamped on the master tool is the radius - Lockplate. from the center of the gage to the step on the master tool. - Compressor turbine assembly. Set gage dial to zero when it is on the master.

Grinding can be minimized by carefully selecting classes to compensate for ovality or eccentricity of the shroud housing. The best fitting class segments is picked after measuring the CT outside diameter and referring to a table from the Engine Maintenance Manual. It is recommended to go 1- class higher (thicker segments) to offset any excessive ovality from the shroud housing.

PT6A-60 SERIES TRAINING USE ONLY MAINTENANCE PRACTICES 12.16 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface HOT SECTION INSPECTION (CONT’D)

Calculate Actual Tip Clearance Before Grinding As Fol- lows: (the numbers used are for examples only) - Dimension stamped on side of - gauge (master).= 4.282" - Dial gage reading.= -0.009" (plus or minus sign is important) - CT largest diameter / 2 (8.532 / 2).= 4.266"

Step 1 = Find the radius of the shroud: (master + dial reading => 4.282" -.009")= 4.273"

Step 2 = Find actual CT tip clearance: (shroud radius - disk radius => 4.273" - 4.266") = 0.007"

Step 3 = Determine material to be removed, assuming required tip clearance is .010".

(actual clearance - required clearance : .007" - .010") = -.003"

We need to grind .003" off the segments.

Note: Refer to Maintenance Manual for proper grinding procedure.

PT6A-60 SERIES TRAINING USE ONLY MAINTENANCE PRACTICES 12.17 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface HOT SECTION INSPECTION (CONT’D)

Fuel Nozzle Functional Check: Pressure Test: Pressure test for leakage between nozzle tip and adapter at Ensures the engine combustion chamber receives properly 500 PSIG fluid pressure or 200 PSIG air pressure, no leak- atomized fuel. age allowed.

Inspection Interval: Fuel Nozzle Cleaning: - 200 hours for new operators. - When spraying, brush tip with a non-metallic brush to - 400 hours max interval afterwards, depending of con- loosen any possible carbon debris. dition. - If above method is not effective, ultrasonically clean nozzles in carbon remover solvent. - Always rinse nozzles in hot water after cleaning, since Spray Pattern Check: carbon solvent is corrosive. - Flow test for spray pattern at 20 PSI. Check for drooling and spitting (none permitted). - There may be an onion or tulip shaped spray pattern. Fuel Nozzle Sheaths: - Flow test for spray pattern at 60 PSI. Check for spray - Inspect sheaths for erosion on the dome top. pattern streakiness, drooling or spitting. - Inspect sheaths for wear at combustion chamber con- - 20% max streakiness is allowed tact area. - Check gap between sheath and adapter flange. - Check concentricity between sheath and adapter ori- Note 1: fice with a .020" drill. All values are for reference only. Always refer to the appropriate Maintenance Manual for proper settings.

Note 2: If a streaking nozzle is found during testing, a visual HSI or borescope inspection of the hot section should be done.

PT6A-60 SERIES TRAINING USE ONLY MAINTENANCE PRACTICES 12.18 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface HOT SECTION INSPECTION (CONT’D)

T5 System Functional Check: Heat Response Test: (T5 Probe Functional Check)

T5 system inspection should be performed during hot sec- This check is done to verify proper functioning of T5 probes. tion inspection with the engine split at flange "C" or when- Ensures T5 probes respond to heat. ever a T5 indication problem is suspected. With engine split at "C" flange, connect test set to alumel and chromel lead. Heat each probe individually and verify Continuity Resistance (Loop) Check: response. Replace faulty thermocouple probe.

Ensures continuity and proper resistance in the T5 probes, bus-bars, wires and terminals. Note: - Each T5 probe can be checked for loop and insulation Disconnect all leads from T5 terminal block on gas genera- resistance if a fault is suspected. tor case (use care, while disconnecting leads, to avoid - Always clean connector carefully to ensure resistance cracking the insulation material) and measure resistance of the system is not disturbed between Alumel and Chromel terminals.

Disconnect T5 probes from bus-bar and measure resis- Trim Thermocouple Check: tance between Alumel and Chromel terminals, refer to Maintenance Manual for resistance limits. This check is done to ensure proper resistance of the trim stick.

Insulation (Ground) Resistance Check:

This check is done to ensure system is not grounded (shorted). Ensures that neither Alumel nor Chromel bus bars are contacting the casing.

Connect test set between alumel or chromel and ground (gas generator case) and measure insulation resistance. Minimum resistance must not be less than specified limit.

PT6A-60 SERIES TRAINING USE ONLY MAINTENANCE PRACTICES 12.19 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface NOTES

PT6A-60 SERIES TRAINING USE ONLY MAINTENANCE PRACTICES 12.20 P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface RIGGING

RIGGING

PT6A-60 SERIES TRAINING USE ONLY RIGGING 13.1 BASIC ENGINE RIGGING

Purpose:

Provide the operator with a basic approach to engine rig- COCKPIT ging. This section defines the logical sequence that should LEVERS be followed when rigging the engine. It also describes the post run-up adjustments necessary to get an ideal cockpit lever to engine response relationship. Use the airframe maintenance manual for specific engine rigging information. CUT-OFF CAM CSU SPEED LEVER BOX LEVER Pre-Rigging Verification: - Ensure that cockpit levers and cables operate freely and do not bind before connecting it to the engine. - Ensure that the engine reversing cable is not damaged and operates freely when disconnected from the beta CSU FCU REVERSE LEVER lever. LEVER - Verify that the propeller reversing lever is connected to the beta valve and make sure the carbon block is in good condition. - Verify that the beta valve is properly connected to the beta lever. - Verify run-out on beta feedback slip ring (.003 max) - Check that beta valve slides freely.

You are now ready to rig the engine.

PT6A-60 SERIES TRAINING USE ONLY RIGGING 13.2 REAR LINKAGE RIGGING

One of the first steps prior to rigging the fuel control unit on Note: the PT6 is to carefully rig the cambox position. Once this is A “rig pin" hole located on the cambox may be used to facil- done, the fuel control unit and the reversing cable can be itate the track point rigging. Ensure that the above proce- rigged. dure applies for a more precise rigging.

Cambox Rigging:

With the airframe power lever cable and the engine reverse cable disconnected from the cambox, move the cockpit power lever through the full range and verify motion is free of binding and excessive friction. - The next step is to find the track point. - Cycle the power lever forward and back slowly until the cockpit idle detent is contacted. - Find the track point by rotating the cambox input lever counterclockwise until the reverse cam moves back 1/ 32 inch (apply light forward force on reversing cam while measuring). - Once the track point is located, position the cambox input lever at the angle specified by the airframe manufacturer. - Cycle the cockpit power lever between maximum forward and reverse position and ensure the power lever cable terminal travel exceeds the required input l lever displacement. - Connect the airframe power lever cable to the cambox input lever

PT6A-60 SERIES TRAINING USE ONLY RIGGING 13.3 WOODWARD FUEL CONTROL RIGGING

1. Disconnect the FCU interconnecting rod and set it's length to 1/8 inch shorter than specified in the airframe maintenance manual (the rod length will be rectified later on).

2. With the rod disconnected position the fuel lever to contact the idle stop without going into the deadband.

3. Connect the FCU inter connecting rod to the proper hole on the FCU actuating lever. Connect the rear end of the rod to the FCU arm using the serrated washer to position the FCU shaft as marked in step 2 (at the idle stop).

4. Remove FCU interconnect rod and lengthen it 1/8 inch (so it goes back to airframe manual recommendation). This will provide some forward deadband (approximately 1/4 inch) on the pedestal before Ng picks up.

5. Move the power lever through the full range (make sure the reverse cable is disconnected). The cam follower pin should not bottom out at either end of the reverse cam slot. In the maximum forward position, the FCU maximum Ng stop screw should contact the FCU maximum stop.

PT6A-60 SERIES TRAINING USE ONLY RIGGING 13.4 REAR LINKAGE (WOODWARD)

AL REVERSING CAM IDLE REVERSING CABLE

LENGHT AS PER AIRFRAME MANU

IDLE REVERSE FORWARD CAMBOX INPUT LEVER CAM FOLLOWER PIN FCU CONNECTING ROD

FCU ARM

MAX FORWARD NG STOP CAM BOX DEAD-BAND ADJUSTMENT

AIRFRAME POWER LEVER CABLE HIGH IDLE ROLLER MAX REVERSE NG STOP HIGH IDLE CAM

PT6A-60 SERIES TRAINING USE ONLY RIGGING 13.5 FRONT LINKAGE RIGGING

Telescopic Interconnect Rod: Rigid Interconnect Rod:

1. Disconnect the reverse cable at the cambox. 1. Disconnect the reverse cable at the cambox.

2. Move the Power Lever in the cockpit between Flight Idle 2. Move the cockpit power lever between idle and maximum and Max Power setting to verify free movement. power position to verify free movement

3. Pull on the Beta Lever and adjust the front clevis so that 3. Disconnect the propeller governor interconnect rod, pull the Beta Valve clevis slot face is flush with the Beta Valve on the beta lever and adjust the front clevis so that the cap. beta valve clevis slot face is flush with the beta valve nut.

4. Adjust the length of the interconnect rod to get the 4. Connect the reverse cable rear clevis to the required hole required gap as specified in the Airframe Maintenance in the reverse cam. Adjust the clevis so that the cable is in manual. light compression (pushed forward) when the clevis pin is installed. 5. Cycle the cockpit levers from idle to max power to verify smooth operation. Adjust the reverse cable pre-load at 5. Connect the CSU interconnect rod in the specified holes the rear clevis connection if excessive friction is and adjust it to get a sliding fit, then shorten thread by observed. The reverse cable will be in tension since it is turning one end 1/2 turn. pushed forward by the Beta valve spring. 6. Cycle the cockpit power lever from idle to maximum to confirm smooth motion. Adjust the reverse cable pre-load at the rear clevis connection if excessive friction is observed.

PT6A-60 SERIES TRAINING USE ONLY RIGGING 13.6 FRONT LINKAGE

FEATHERING TIME ADJUSTMENT

RESET ARM MAX. STOP DO NOT ADJUST

FRONT CLEVIS

MAX PROP SPEED BETA LEVER (FORWARD)TO CAM BOX

PNEUMATIC MINIMUM ADJUSTMENT (MAX REVERSE Np) BETA VALVE CAP NUT

RIG FLUSH

INTERCONNECT ROD (GAP AS PER AIRFRAME M.M.)

CLEVIS

VALVE BETA VALVE

PT6A-60 SERIES TRAINING USE ONLY RIGGING 13.7 FUEL CONDITION LEVER

- Disconnect control cable from the fuel idle reset/cut- Propeller Lever: off lever - Move the cockpit propeller lever fully forward. Ensure - Insert rigging pin through the idle reset/cut-off lever that speed select lever contacts maximum Np stop - Place cockpit fuel condition lever to ground idle and screw. Adjust console stop to comply. adjust the aircraft cable to fit to the appropriate hole on - Move cockpit propeller lever to feather. Ensure speed the idle reset/cut-off lever select lever fully depresses the feathering valve - Remove rigging pin plunger.

Ensure : Note: - Fuel condition lever moves freely throughout the entire Speed select levers should be loaded slightly against the range maximum Np when maximum propeller speed is selected.

At Cut-Off Position : Post Rigging Check: - Ensure that there is a positive contact with the cut-off stop. Ensure the propeller feathers when the cockpit propeller - Ensure that the unloading valve screw fully depresses lever is halfway through the feather detent. the unloading valve plunger.

At High Idle Position : - Ensure high idle stop is contacted

Prior To Starting The Engine: - Disconnect the fuel line going to the flow divider - Perform a wet motoring run to confirm Positive fuel cut-off - Ensure cut-off happens when the fuel lever position is halfway through the cut-off detent. - Check low and high idle speed as per aircraft maintenance manual

PT6A-60 SERIES TRAINING USE ONLY RIGGING 13.8 FUEL & PROPELLER LEVER RIGGING

FEATHER STOP SCREW RESET ARM MAX. STOP DO NOT ADJUST MAX. SPEED ADJ.

HIGH IDLE FCU STOP CUT-OFF (ONLY IF STOP STAGGER EXISTS)

WOODWARD

CSU

PT6A-60 SERIES TRAINING USE ONLY RIGGING 13.9 POST RUN UP ADJUSTMENTS

Prior to running the engine ensure that: - The FCU maximum Ng stop is contacted when the cockpit power lever is advanced to the maximum position. - The cut-off stop is contacted when the condition lever is at the cut-off position. - The speed select lever on the CSU makes firm contact with the maximum speed stop.

Symptom Fix - Ensure rigging was done properly Idle Ng Too High - Adjust Ng speed as per manual’s instructions - Ensure there are no P3 or Py leaks Idle Ng Too Low - Adjust as per manual instructions Before adjusting make sure that: - The deadband is the same on the two engines - The power lever travel movement from idle to take off is the same on the Ng Pick-Up Point Is Different On two engines (stagger is constant). The Two Engines To Adjust: (Constant Stagger) - To move the pick-up point forward on the quadrant, turn the serrated washer clockwise. (Do not change the rod length) NB: 2 teeth change on serrated washer = .040" movement on the cockpit quadrant approximately. Before adjusting - Ensure low and high idle speeds are the same on both engines Unequal Power Lever Travel - Ensure maximum Np is the same on both engines. Movement From Idle To Take Off To Adjust: Between The Two Engines - To shorten the power lever travel, (PLA ahead) shorten FCU interconnect- (Progressive Stagger) ing rod - Reposition the pick-up point by adjusting the serrated washer (counterclockwise in this case)

PT6A-60 SERIES TRAINING USE ONLY RIGGING 13.10 POST RUN UP ADJUSTMENTS (CONT’D)

Symptom Fix - Verify position of the beta valve is identical on the two engines when the cockpit power lever is advanced halfway between idle and maximum power. Primary Blade Angle Check; Different - Adjust beta valve position using the reversing cable clevis end (small Torque On The Two Engines adjustment) or adjust beta nuts if airframe maintenance manual permits (big adjustment) - Send propeller to an overhaul shop if beta nuts adjustment is not allowed. Beta valve position has a limited effect on PBA. - Confirm the beta valve position is flush with the beta valve cap nut. - Ensure the reverse cable clevis is connected to the specified reverse Propeller Zero Pitch Position (Np cam hole. Increase In Rearward Deadband) Is - Ensure the cambox track point is rigged the same on the two engines. Staggered On The Two Engines - Perform primary blade angle check (Calibrate torque transducer). Adjust PBA as required - Verify track point rigging Pilot Reports YAW During Approach - Verify beta valve rigging - Perform primary blade angle check

PT6A-60 SERIES TRAINING USE ONLY RIGGING 13.11 TWIN ENGINE RIGGING TROUBLESHOOTING

Condition 1 Ideal Condition. Condition 5 Reverse Pick-Up Point Are Split - Adjust deadband screw on the right hand engine May vary from airframe to airframe. The Airframe Mainte- (CCW) to reduce the band. This will change the dead- nance manual provides a description of the required set- band in forward as well. tings after engine rigging. - Reposition the deadband using the serrated washer (.003” feeler gauge test). Start engine and re-adjust the idle speed. Condition 2 Ng Pick-Up And Target Points Are Split. - Displace the pick-up point with the serrated washer. This will also bring the power lever more or less in line. Condition 6 Beta Valve Tracking Point Is Staggered - Also the deadband must be adjusted. (Np increases in Beta). - Verify the Cambox reverse “track point” is rigged cor- rectly. Condition 3 Power Lever Stagger For Equal Torque - Verify “pre-loading” of pin connecting the reverse cam - Correct the stagger by lengthening the FCU intercon- and the clevis. necting rod on the right hand side engine. - This will move the pick-up point forward which can be corrected by adjusting the serrated washer on the right Condition 7 Forward & Reverse Pick-Up Point Not hand side engine. Matched - Move deadband using serrated washer (but do not adjust angle) rearward on right engine Condition 4 Ng Pickup Point Split But Equal At - Use paper check to have both engines at same posi- Power. tion - Lengthen the FCU interconnect rod on the right hand side engine. - Adjust deadband screw (.003” gauge test) and the serrated washer to set the “deadband angle” and “pick-up point position” the same on both engines. - Start engine and verify the idle speed.

PT6A-60 SERIES TRAINING USE ONLY RIGGING 13.12 POST RUN-UP ADJUSTMENTS (TWIN ENGINE)

1 234

TQ TQ TQ TQ TQ TQ TQ TQ

PU PU INC PU PU PU PU PU PU BVT IDLE DETENT PU PU BVTPU BVTPU BVTPU BVT PUBVT BVTPU PU P O W

E BVT R 5 6 7 IDLE IDLE

TQ L L TQ TQ TQ TQ TQ I I F F T T PU PU PU PU PU PU

IDLE PU DETENT PU PU PU PU BVT BVTPU BVT BVT BVT BVT REVERSE

LEGEND

TQ : CRUISE TORQUE PU : NG PICK -UP POINT Z T : ZERO THRUST POSITION BVT:BETA VALVE TRACKING

PT6A-60 SERIES TRAINING USE ONLY RIGGING 13.13 TRAINING MATERIAL CHANGE REQUEST

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PT6A-60 SERIES TRAINING USE ONLY RIGGING 13.14