ENGINES

ENGINES The Rolls Royce (Allison) AE3007A is a dual spool, axial flow, high bypass ratio (5:1) turbofan engine, rated at approximately 7500 lbs of thrust. The engine is controlled by two redundant Full Authority Digital Electronic Controls (FADEC).

HIGH PRESSURE SPOOL (14:2) The High Pressure Spool consists of a fourteen stage HP Compressor. Stages one through five have Variable Geometry Inlet Guide Vanes controlled by the FADEC . HP Compressor bleed air is available at the 9th and 14th stages. The HP Turbine has two stages.

LOW PRESSURE SPOOL (1:3) The Low Pressure Spool consists of a single stage high bypass LP Fan which is driven by a by a three stage LP Turbine.

ENGINE ACCESSORIES The Gearbox is driven by the High Pressure Spool and powers the following accessories:

 Air Turbine Starter  Permanent Magnet Alternator  Fuel Pump Metering Unit  Oil Pump  Hydraulic Pump  DC Generators (2)

ENGINE FUEL SYSTEM The Engine Fuel System is comprised of:

 Fuel Pump and Metering Unit (FPMU). The FPMU is controlled by the FADEC. The FPMU provides:

o High Pressure Fuel o Filtering o Fuel Metering

 Fuel Cooled Oil Cooler (FCOC).

o A dual purpose heat exchanger providing cooling to the engine oil and heating of the fuel. The Thermal/Pressure Bypass Valve bypasses very cold oil and very hot fuel.

 Compressor Variable Geometry (CVG) Actuator

o High pressure fuel is used to hydraulically move the Inlet Guide Vanes.

 Fuel Flow Meter  Fuel Nozzles

ENGINE OIL SYSTEM The Engine Oil System components are:

 Oil Tank (pressurized) [12 US Quarts]  Oil Pump and Scavenge Pump  Oil Filter with Bypass Valve (Allows engine oil to bypass the Oil Filter if clogged)  Air Cooled Oil Cooler (ACOC)  Fuel Cooled Oil Cooler (FCOC)  Thermal/Pressure Bypass Valve (Allows engine oil to bypass the ACOC and FCOC)

The system is self contained, pressure regulated and a re-circulating dry-sump system. Oil from the Oil Tank goes to the Oil Pump, to the Filter, to the ACOC, FCOC, to the accessory Gearbox and sumps. The return oil is collected, goes through a screen, and returns to an Air/Oil Separator in the Oil Tank. A Bypass Valve provides a bypass of the Oil Filter (when clogged) and the ACOC and FCOC (when cold).

ENGINE BLEED AIR Air is bled from the compressor 9th stage during engine starting to assist with accelerating to idle RPM. The engine also provides bleed air to the Pressurization, Air Conditioning, and Anti-ice Systems through the Engine Bleed Valve (EBV). Bleed air for these systems are extracted from the 9th or 14th stage, depending on the systems being used.

ENGINE ELECTRICAL SYSTEM: The Engine Electrical System primarily uses a Permanent Magnet Alternator (PMA) for control and Ignition. It is driven by the Gearbox. The PMA has four separate electrical windings:

 (2) Single Phase Windings which supply power to the Ignition systems above 10%.N2

 (2) Three Phase Windings which supply power to FADECs above 50% N2

o The Essential DC bus powers the FADECS below 50% N2 o The Essential DC bus powers the FADECS in case of emergency backup o One Three Phase Winding supplies a N2 Speed Signal to the FADEC.

ENGINE IGNITION SYSTEM The Engine Ignition System has dual redundant Exciters and Igniters located on opposite sides of the engine. Each Exciter and Igniter is supplied by a separate FADEC by a winding on the PMA. The Exciters and Igniters are alternated each engine start. Engine start in-flight uses both exciters.

IGNITION knob selected to ON.

 From Engine start cycle above 10% N2, until selected to AUTO or OFF

IGNITION knob selected to AUTO

 The active FADEC activates its Igniter during Engine start 14% N2 through 56% N2  Both FADEC’s Igniters are activated at 10% N2 during an inflight restart  Both FADEC’s Igniters are activated during Auto Relight above 53% N2

IGNITION knob selected to OFF.

 Igniters are de-activated  Fuel SOV is closed during engine start command  Fuel SOV remains open if engine is already started

ENGINE PNEUMATIC STARTING SYSTEM The Engine Pneumatic start system components are the:

 Air Turbine Starter (ATS)  Start Control Valve (SCV)

The ATS is located in the gearbox. The ATS converts pneumatic energy into driving torque for the engine HP Compressor to accelerate the engine to a self sustaining speed during the engine start cycle. The ATS exhaust is discharged from the engine nacelle.

The ATS is activated by the SCV. The valve is electrically controlled and pneumatically operated. Moving the Start/Stop Selector to START allows the FADEC to control the SCV. The SCV can be manually actuated by maintenance personnel if there is problem with the valve or the electrical system. The SCV housing has a visual indication of the valve position. The SCV is spring- loaded to the CLOSED position. If the SCV remains open after 53% N2, a caution message is displayed on EICAS. Three pneumatic sources can be selected:

 External Start Air  APU Bleed Air  Engine Bleed Air

ENGINE INDICATING SYSTEM Engine Indications are displayed through the Engine Indicating and Crew Alerting System (EICAS). EICAS, MFDs and the FADECs receive inputs from the following sensors and switches:

 Oil Pressure/Temperature Transducer (FCOC)  Low Oil Pressure Switch (FCOC)  Oil Level Transducer (Oil Tank)  Low Oil Level Switch (Oil Tank) o Activates at 6 quarts  Oil Filter Impending Bypass Indicator (Oil Filter)  Magnetic Indication Plug o Activates when magnetic material bridges its contacts  Fuel Temperature Sensor (FCOC) o Activates at +5C  Fuel Filter Impending Bypass Indicator (FPMU Fuel Filter)  Fuel Flow Meter (FPMU)  Vibration Sensors (Fan and Turbine Rotors)

ENGINE CONTROL SYSTEM

FADEC (Full Authority Digital Electronic Control FADECs A and B are redundant and independently capable of controlling the engine. The FADECs alternate powerplant control after each ground start. One is active and the other is in standby mode. The FADECs communicate with each other for the purpose of status monitoring, Automatic Takeoff Thrust Control System and Thrust Reverser function.

N1 CONTROL Based on control inputs from the Thrust Levers and the Powerplant Control Panels, the FADEC compares the requested fan speed (N1 REQUEST) and the measured fan speed. An error signal is used to command the FPMU to adjust fuel flow and in order to bring the error to zero. N1 REQUEST is indicated as a GREEN TRIANGLE on the EICAS.

The FADEC computes the maximum available thrust (N1 TARGET) for each of the selected thrust rating modes. N1 TARGET is indicated by BLUE DIGITS and a BLUE BUG on the EICAS using:

 Temperature (REF TO Temp or TAT)  Pressure Altitude and Mach Number from ADCs  Bleed Air configuration  Anti Ice configuration (Ref A-ICE Condition or Anti Ice System feedback)

FADEC CVG CONTROL The FADEC schedules proper Compressor Variable Geometry Inlet Guide Vane position to increase efficiency and stall margins. The FADEC senses the position of the CVG IGVs and commands the FPMU to deliver high pressure fuel to the CVG Actuator to maintain the required setting.

FADEC FAULT CONTROL AND ALERTING At initial power up, the active FADEC is A. The standby FADEC continuously monitors all parameters of the engine operations, including self tests and fault detection. The EICAS will display all alerts or log the FAULT(s) in the Central Maintenance Computer (CMC).

The FADEC is highly tolerant of faults and can accommodate multiple faults with no engine degradation. The concept is to keep the FADEC operating as long as possible before switching to the other standby FADEC. If a fault is detected, the active FADEC can borrow data from the standby FADEC. If the fault will result in degraded Engine performance or a loss of control, the standby FADEC will automatically assume command.

Manual selection of the standby FADEC can be made by moving the FADEC Selector knob to the ALTN position. This will override the automatic selection of the controlling FADEC, unless it is incapable of controlling the engines.

Moving the FADEC Selector knob to the RESET position will clear recorded, inactive faults.

FADEC PROTECTIONS (N1, N2, ITT, ACCLERATION, DECELERATION) The FADEC does not allow engine parameters to be exceeded except during a start. The FADEC will limit fuel flow in order not to exceed N1, N2, or ITT limits. The FADEC will shut down the Engine in the event of a N1 or N2 overspeed condition. The FADEC will adjust fuel flow to prevent surge during acceleration or lean blow out during deceleration.

FADEC AUTO RELIGHT The FADEC flameout and auto-relight detection logic detects an engine flameout and attempts an automatic relight before the engine loses power, if N2 is above 53%. If a relight cannot be successfully executed, the FADEC commands an Engine shutdown. During in flight restarts, both Igniters are energized. The Auto Relight function is available when the IGNITION selector knob is set to AUTO.

FADEC DISCRETE OUTPUTS Each FADEC provides two control signals: N2 Speed Switch and ECS OFF Signal.

N1 REVERSIONARY MODE If there is a total failure of N1 inputs to both FADECs the FADEC reverts to the N1 Reversionary Mode. In this mode the FADEC synthesizes N1 (N1 SYN) as a function of N2 and the ambient conditions. The FADEC will control the Engine by governing N2 speed. Engine control response times will be greater, and actual thrust output may be less accurate.

ENGINE SHUTDOWN The Engine can only be shutdown through electrical means or the lack of any electrical power. Normally the Engine is shutdown through the FPMU Fuel Shutoff Valve (SOV) by using the START STOP SELECTOR knob placed to STOP. The Engine FIRE Extinguishing Handle will also shutdown the engine.

THRUST MANAGEMENT The FADEC manages thrust in the following modes:

 T/O-1 -- Button on Control Pedestal  ALT T/O-1 -- Selected through the Alternate Takeoff Data Setting Procedure.  CON -- Button on Control Pedestal  CLB -- Button on Control Pedestal  CRZ -- Button on Control Pedestal

If the Thrust Levers are positioned at THRUST SET, the FADEC's command the thrust associated with the Thrust Mode Selection (N1 TARGET). If the Thrust Levers are positioned between THRUST SET and FLT IDLE the FADEC's command intermediate mode thrust (N1 REQUEST). Intermediate thrust settings are not commanded between FLT IDLE and MIN REVERSE. Normally both Engines operate in the same thrust rating mode. If the Engines do not agree on the thrust rating mode for a given time period (340 ms), maximum takeoff thrust will be selected on both.

TAKEOFF DATA SETTING PROCEDURE

 Takeoff Mode (T/O Mode for either T/O-1; T/O: or ALT T/O-1)  Reference Takeoff Temperature (REF TO TEMP from SAT, ATIS, etc.)  Reference Anti Ice Condition (ON or OFF)

THRUST MANAGEMENT - MAXIMUM TAKEOFF (T/O-1 or T/O) MODE The engine produces the Maximum Thrust possible for the existing ambient conditions. The FADEC will select this mode for any of the following conditions:

 FADEC power-up or power interruption  Takeoff Data Setting Procedure is successfully completed for setting T/O-1  T/O Mode Button  Thrust Lever advanced beyond THRUST SET  Gear transitions from UP to DOWN & LOCKED below 15,000'.  Both Engines do not agree on their Thrust Modes for 340 ms.

THRUST MANAGEMENT - ALTERNATE TAKEOFF (ALT T/O-1) MODE This mode is selected only through the Takeoff Data Setting Procedure. This function is available:

 Only on the ground with Thrust Lever Angle (TLA) < 50°.

THRUST MANAGEMENT - MAXIMUM CONTINUOUS (CON) MODE This mode is selected by pressing the CON Button. It is used only when one engine inoperative and is inhibited on the ground. The FADEC's will select the mode if either:

 PA > 300' above the Takeoff Altitude and Gear is NOT DOWN & LOCKED  PA > 1700' above the Takeoff Altitude.

THRUST MANAGEMENT - MAXIMUM CLIMB (CLB) MODE This mode is selected by pressing the CLB Button. It is used only when both engines are operating and is inhibited on the ground. The FADEC's will select the mode if either:

 PA > 500' the Takeoff Altitude and Gear is NOT DOWN & LOCKED  PA > 1700' the Takeoff Altitude.

THRUST MANAGEMENT - MAXIMUM CRUISE (CRZ) MODE This mode is selected by pressing the CON Button. It is used only when both engines are operating and inhibited on the ground. The FADEC's will select the mode if either:

 PA > 500' the Takeoff Altitude and Gear is NOT DOWN & LOCKED  PA > 1700' the Takeoff Altitude

GROUND / FLIGHT IDLE THRUST SCHEDULES Idle thrust is scheduled for ground and flight modes. If the FADEC's receive an indication that the Anti-Ice is ON, the flight idle is rescheduled to provide the required bleed air pressure and temperature. Automatic Anti-Ice flight idle rescheduling is inhibited below 15,000' if the gear is DOWN.

AUTOMATIC TAKEOFF THRUST CONTROL SYSTEM (ATTCS): If an engine fails during takeoff the ATTCS automatically resets thrust on the good engine to Maximum Takeoff Thrust. ATTCS capable modes are ALT T/O-1 (145) and ALT T/O-1 and T/O (135,140)

ARMING:  TLA is increased above 45 degrees.

DISARMING:  TLA is reduced below 42 degrees  ATTCS is triggered

TRIGGERED:  TLA for the opposite engine is reduced below 38 degrees  FADEC receives a signal that the opposite engine is inoperative.  The opposite engine does NOT indicate being ARMED within two seconds after the associated engine is ARMED.

THRUST REVERSER SYSTEM The Thrust Reversers are an option on the aircraft. The function of the Reversers is to assist stopping the aircraft after landing or during a rejected takeoff. When deployed, the doors block and redirect the engine exhaust forward. Each engine has two hydraulically operated doors. When they are closed they form part of the exhaust nozzle.

The actuators have triple, independent locking systems to avoid inadvertent deployment in flight. Should a Reverser deploy in flight, the FADEC will automatically select IDLE thrust on the Engine.

Each FADEC will command Maximum Reverse thrust only on the ground when the associated thrust reverser is deployed and the associated thrust lever is requesting reverse thrust when either of the following occur:

 Both main landing gears indicate on the ground and the main landing gear or wheel speed is above 25 knots  All three landing gears indicate on the ground

If the Thrust Lever is requesting forward thrust, the FADEC will command IDLE thrust if the associated engine thrust reverser indicates that there is a “not stowed” or a “deployed” condition.

Thrust Reverser status is displayed on EICAS. An amber REV indicates that the reverser is in transition. A green REV indicates that the upper and lower Thrust Reverser doors are fully deployed. ENG ATTCS FAIL The thrust lever is moved to the THRUST SET position but ATTCS is not armed (engines running in an ATTCS capable mode).

ATTCS FAIL ATTCS failed associated with a low N1.

E 1 (2) ATTCS NO MARGIN The engine has no ITT margin to achieve the rated takeoff thrust if ATTCS is triggered.

E 1 (2) OIL LOW PRESS The oil pressure has dropped to below 34psi and the engine is running or the pressure switch has failed at the closed position and the engine is not running.

E 1 (2) LOW N1 Engine has failed.

E 1 (2) FUEL LO TEMP The fuel temperature in the engine has dropped below 5C.

E 1 (2) ATS SOV OPN The engine ATS shutoff valve (SCV) remained open above 53%N2

ENG REF A/I DISAG Disagreement between the REF A ICE condition selected by the pilot and the actual anti-icing system condition has been detected by the engine control.

E 1 (2) CTL A (B) FAIL A failure in the engine control system has been detected.

E 1 (2) TLA FAIL Thrust lever angle sensor has failed

ENG NO TO DATA Takeoff data has not been successfully entered with engine running and above 53% N2

ENG 1 (2) REV FAIL Thrust reverser doors not stowed and in transit with thrust levers set above IDLE or thrust levers set below IDLE in flight.

ENG 1 (2) REV DISAGREE At least one thrust reverser door not fully open; or thrust reverser system not isolated from hydraulic system (thrust lever set at or above IDLE); or door locking or position switch signal failure with thrust levers set at or above IDLE (ground only).

FADEC ID NO DISP Different FADEC versions installed in the aircraft.

ENG 1 (2) OUT N2 has dropped below 54% (underspeed shutdown limit) uncommanded.

E 1 NO DISP Associated FADEC has detected a non-dispatch failure condition.

E 1 (2) OIL IMP BYP The differential pressure across the oil filter has exceeded 22psi or chip detector has picked up metal particles.

E 1 (2) FUEL IMP BYP The differential pressure across the fuel filter as exceeded 11psi.

E 1 (2) ADC DATA FAIL Loss of both ADC data or synthesized T2 used as temperature source.

E 1 (2) CTL A (B) DEGRAD Engine control degraded.

E 1 (2) SHORT DISP A dispatchable MEL category B input sensor fault to the FADEC was detected.

CHECK A1, A1/2, A1/3 PERF Indicates which FADEC version is installed in the aircraft.

E 1 (2) IDL STP FAIL Idle stop has failed.