Next Generation Commercial Aircraft Engine Maintenance, Repair, and Overhaul Capacity Planning and Gap Analysis
by
Amanda J. Knight B. S. Mechanical Engineering, The University of Texas at Austin, 2006 M.S. Aerospace Engineering, The University of Southern California, 2011
Submitted to the MIT Sloan School of Management and the Department of Civil and Environmental Engineering in Partial Fulfillment of the Requirements for the Degrees of
Master of Business Administration and Master of Science in Civil and Environmental Engineering
In conjunction with the Leaders for Global Operations Program at the Massachusetts Institute of Technology
June 2018 2018 Amanda J. Knight. All rights reserved. The author hereby grants MIT permission to reproduce and to distribute publicly paper and electronic copies of this thesis document in whole or in part in any medium now known or hereafter created.
Signature of Author: Signature redacted Department of Civil and Envirnmental Engineering, MIT Sloan School of Management May 11,2018
Certified by: Signature redacted __ DI Roy Welsch, Thesis Supervisor Professor of Statistics and Engineering Systems
Certified by: Signature redacted Dr. Daniel Wh The i Supervisor Senior Research ScientisU/Eyneritust Lecturer, IVVT Leaders for obal Operations
Certified by: _____Signature redacted ______Dr. David Simchi-Levi, Thesis Supervisor Prof"or,9 C ppdEnvironmental Engineering
Accepted by: Signature redacted____ Jesse H. Kroll Profesor of Civil and Environmental Engineering Chair, Graduate Program Committee
Accepted by: Signature redacted MHro MASSACHUSETTS INSTITUTE ' M PM ManuraHerson OF TECHNOLOGY co Director, MBA Program, MIT Sloan School of Management
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Page | 2 Next Generation Commercial Aircraft Engine Maintenance, Repair, and Overhaul Capacity Planning and Gap Analysis
by
Amanda J. Knight
Submitted to the MIT Sloan School of Management and the Department of Civil and Environmental Engineering on May 11, 2018 in partial Fulfillment of the Requirements for the Degrees of Master of Business Administration and Master of Science in Civil and Environmental Engineering
ABSTRACT
A critical element in maintaining engine safety and in providing post-production service and support of a commercial aircraft engine is the complete worldwide network of maintenance, repair, and overhaul facilities. Matching forecasted shop visit demand to network-wide capacity is essential to ensuring the required resources are in place to quickly repair and return these assets to the airline customer. A capacity analysis methodology is developed to characterize and analyze the current network capacity for the PW11 OOG Geared Turbofan engine model for Gate 3 Engine Testing processes. This capacity model is then compared to the anticipated monthly shop visit demand for engine repair services through 2026. By identifying capacity shortages earlier in the program, Pratt & Whitney can proactively plan for and fund additional resources to improve capacity, ensuring the required capacity is in place when demand materializes to reduce shop visit delays. The results of the PW1 1 QOG capacity study are utilized both to provide recommendations for the anticipated timeframe when additional resources will be required to meet projected demand and to outline major planning milestones required to meet the resource need date.
Thesis Supervisor: Dr. Roy Welsch Eastman Kodak Leaders for Global Operations Professor of Management Professor of Statistics and Engineering Systems
Thesis Supervisor: Dr. Daniel Whitney Senior Research Scientist and Senior Lecturer in Mechanical Engineering
Thesis Supervisor: Dr. David Simchi-Levi Professor, Civil and Environmental Engineering
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Page | 4 Acknowledgements
The author wishes to acknowledge the Leaders for Global Operations program for its support of this work.
Many thanks to the awesome folks working on the Pratt & Whitney Geared Turbofan program for their endless support, kindness, and patience: o Rob Griffiths for your ideas and guidance in simplifying and focusing our capacity model o Dan Dinneen for always pointing me in the right direction, to the right people to get things done... and for the 2:00 pm coffee excursions o Katie Allen for keeping me in the loop on shop updates, for the much-needed stress- relieving afternoon walkabouts, and for making me feel like part of the GTF family o Chris Burrows for answering my never-ending stream of questions about CEC and VSMs o Joe Wagner and Tim Moran for sharing your GTF expertise and incredible knowledge of test processes o Liana Layug for your amazing sense of humor and for providing opportunities to get involved at Pratt & Whitney outside of GTF o Michelle Porter for your insight into Engine Services and engine scheduling and for the fun weekends out and about.. .even the 3-mile-turned-10-mile hike o Stephanie Castillo for your incredible warmth and support during my time in East Hartford o Dianne Durgan for helping me book conference rooms and then find them in the OBG- maze
A huge thanks to Chris Cable and Tyler Kane from the PW Enterprise Capacity and Material Planning Strategy group for providing your capacity planning and analysis expertise and for being great travel partners for our multitude of site visits
Thanks to Travis Gracewski and Kevin Thomas for ensuring my internship and thesis started out on the right foot and for the always-valued career advice
Thanks to my advisors Roy Welsch, Dan Whitney, and David Simchi-Levi for your welcomed advice, expert guidance, and recommendations to make this thesis a worthwhile endeavor
Thanks to Brienna Hudson for encouraging me to get out of my comfort zone and embark on this exciting adventure at MIT
Thanks most of all to my mom, dad, and brother for enduring my crazy-excited 6-month-long engine story, for providing your love and support during my last degree program ever (for real this time...), and, especially to my mom, for making five (5!) semi-harrowing road trips between Oklahoma City and Boston with three ornery cats.
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Page 1 6 Table of Contents A B S T R A C T ...... 3 L is t of F ig u re s ...... 8 L is t o f T a b le s ...... 9 1 . In tro d u c tio n ...... 1 1 1.1. Project M otivation ...... 11 1.2. General Problem Statement, Goals, and Scope...... 12 1 .3 . B a c k g ro u n d ...... 1 3 1.3.1. Engine Development and Aerospace Industry Background...... 13 1.3.2. Afterm arket Operations...... 16 1.3.3. GTF Program History, Development, and Status ...... 18 1.3.4. GTF Engine M RO Network ...... 24 2 . M e th o d s ...... 2 8 2.1. Literature Search...... 28 2.2. In-Shop Investigation and Interviews ...... 30 2.3. Capacity M odel Development Overview ...... 31 2.4. Production Readiness Decision Chart ...... 31 3. Capacity M odel Developm ent - Gate 3 Engine Testing...... 33 4. Gate 3 Engine Testing Capacity and Gap Analysis ...... 40 4.1. Current Facilities / Test Cells and Facilities In-W ork...... 41 4.2. Tooling - Duct Sets, Instrumentation...... 42 4.3. Manpower / Labor ...... 43 4.4. Capacity per Shop and Conclusions...... 44 5. Conclusions, Recom mendations, and Future W ork ...... 57 5 .1 . C o n c lu s io n s ...... 5 7 5.2. Recom m endations ...... 58 5.3. Future W ork ...... 62 6. Appendix A - Initial Gate 1 Disassembly and Gate 3 Assembly Framework...... 64 6.1. Proposed Capacity Model...... 64 6.2. Prelim inary Results for Single Facility ...... 67 7 . R e fe re n ce s ...... 7 3 7 .1 . R e fe re n ce s ...... 7 3 7.2. G lossary of Acronym s...... 75
Page | 7 List of Figures Figure 1: Jet E ngine D evelopm ent ...... 14 Figure 2: GE's Lockland Plant and the CF6 Engine...... 15 Figure 3: RR's Eagle Production Line and the Trent 1000 Engine...... 15 Figure 4: PW's Wasp Engine and PW11 OOG GTF Engine ...... 16 Figure 5: Conventional Engine Architecture ...... 19 Figure 6: Geared Turbofan Architecture...... 19 Figure 7: TALON X Combustor ...... 22 Figure 8: G T F N oise R eduction...... 22 Figure 9: Overhaul Process Steps...... 25 Figure 10: Gates, Milestones, and TAT for Repair Process...... 26 Figure 11: Map of GTF MRO Facilities...... 27 Figure 12: Queue Length vs. Capacity Utilization...... 28 Figure 13: MRO Conceptual Framework ...... 29 Figure 14: Example Format for Working Days Documentation ...... 33 Figure 15: Time Available per Shift per Site ...... 34 Figure 16: Efficiency over Time per Site...... 34 Figure 17: Total Time Available per Month per Site...... 35 Figure 18: Resources Available per Site ...... 35 Figure 19: Light/Medium Workscope Cycle Times and Reductions...... 36 Figure 20: Heavy MTS Workscope Cycle Times and Reductions...... 36 Figure 21: Input Table for Workscope Percentages ...... 37 Figure 22: Market Share per Year by Site ...... 38 Figure 23: PW Test Facility in Middletown, CT ...... 41 Figure 24: MTU Test Cell in Hannover, Germany ...... 41 Figure 25: D uct S et Installed ...... 43 Figure 26: Market Share through 2020...... 47 Figure 27: Aggregate Utilized Capacity of GTF Test Network through 2020...... 48 Figure 28: Utilized Capacity at each Shop through 2020...... 50 Figure 29: Aggregate Utilized Capacity of GTF Test Network for 2021-2024 ...... 52 Figure 30: Utilized Capacity at each Shop, 2021-2024...... 53 Figure 31: Aggregate Utilized Capacity of GTF Test Network for 2025-2026 ...... 54 Figure 32: Utilized Capacity at each Shop, 2025-2026...... 55 Figure 33: PRDC for New Test Cell(s) and Duct Set(s)...... 59 Figure 34: PRDC for New Partnership(s) ...... 60 Figure 35: Example Resource Matrix ...... 66 Figure 36: Site 2 Gate 1 and Gate 3 Available Hours...... 70 Figure 37: Site 2 Capacity and Bottlenecks...... 71 Figure 38: Loading by Process - Heavy Workscope ...... 71 Figure 39: Loading by Process - Light Workscope ...... 72
Page 18 List of Tables T a b le 1 : G T F F a m ily ...... 2 3 Table 2: GTF Test Cells Available...... 42 Table 3: GTF Test Cells In-W ork...... 42 Table 4: GTF Duct Sets Available and On Order...... 43 Table 5: GTF Test Sites and Tim ing...... 45 Table 6: GTF Test Site W ork Schedules ...... 45 Table 7: GTF M RO Repair Facilities Available or In-W ork...... 68 Table 8: Available W ork Schedules per Site...... 69
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Page 110 1. Introduction
1.1. Project Motivation Pratt & Whitney (PW), a business unit of parent company United Technologies (UTC), designed, developed, and produced a next-generation commercial aircraft engine intended to reduce fuel burn, noise, emissions, and maintenance cost, providing a new level of performance and operational efficiency for airline customers. This new PurePower@ Geared Turbofan@ (GTF) engine family required an extensive network of Maintenance, Repair, and Overhaul (MRO) facilities to address engine off-wing maintenance needs and to quickly return these engines to serviceability. Many GTF engines are predicted to require in-shop maintenance within the next ten years for two reasons. First, high customer demand for the GTF-powered airframes has driven new engine production to higher than expected levels. Second, unexpected early technical and design issues have led to in-service performance deterioration and earlier than planned maintenance shop visits. To meet these forecasted maintenance needs, PW requires a deeper understanding of current network-wide repair capacity for Gate 3 (Engine Testing), to include where additional resources are needed in the repair process to meet the desired Turn-Around Time (TAT) and when those resources are needed to be operational.
PW strives to deliver a high-quality GTF engine on time, every time for their end customers, the commercial airlines. Delays in the aftermarket repair Disassembly, Assembly, and Test (DAT) processes of an aircraft engine prevent the return of that asset to the customer. When an aircraft is grounded due to engine problems and no spare engines are available, the airline loses both passengers and revenue and damages its reputation, which may impact the airline's choice of airframe and engine model on future procurements. Gaining an improved understanding of the critical relationship between MRO resources and speed of an engine's return to service will enable PW to position DAT resources when and where they are needed, resulting in shorter shop turn-times, improved responsiveness to emergent airline needs, and maximum value delivered to the customer. Delivering on commitments will provide financial value to PW's shareholders and will position PW to remain a market leader in the highly- competitive aircraft engine production and services markets.
While this thesis demonstrates the usefulness of the analysis framework with an aerospace- based case study, the analysis methodology presented is widely applicable and would provide
Page 111 benefit in any number of industries where limited resources are required to be allocated to move a product through a shop repair flow line.
1.2. General Problem Statement, Goals, and Scope The engine repair process is broken down into "gates" or major phases of work that the engine must progress through in a specific order to complete the repair. Gate 1 is Engine Disassembly and Inspection; Gate 2 is Engine Repair; and Gate 3 is Engine Assembly and Testing. In Gate 3 (Engine Testing) for the GTF engine family, an initial internal review of network capacity has shown that currently available capacity will not meet predicted future shop visit demand through 2026. A capacity study was completed in May 2017 outlining the current capacity available and potential strategic options for meeting the upcoming capacity shortfall. This thesis has proposed a framework for validating both currently available and in-development capacity by refining expectations and assumptions for future shop visit demand, modeling shop capacity across all GTF MRO partners, proposing methods for expanding shop capacity, and linking timelines and funding milestones to increase GTF MRO capacity to meet this anticipated increase in demand.
In support of this problem statement, the following goals were defined: * Characterize and analyze the current and planned capacity for Gate 3 Testing for the PW1100G GTF model. * Compare current capacity available with estimated capacity required to meet forecasted repair demand. If available capacity is inadequate, identify key decision and funding milestones to add capacity where and when it will be needed. " Analyze how learning curves impact future estimates of capacity needed. * Assess methods of performance measurement at each site and current means for knowledge sharing of best practices across sites.
The following processes were included in the overall engine return to service process and were found to impact the total TAT of the repair process. However, the focus of this thesis was on defining a framework for analyzing and characterizing a network's capacity, using the GTF Gate 3 Testing processes as a case study to explore the viability of this new framework. The following out-of-scope items were considered at a high level. A follow-on analysis may be developed to explore the use of the herein described framework for investigation of and improvement in these areas: 0 Gate 0: Engine pre-induction activities
Page 112 * Gate 1: Engine disassembly, inspection, and cleaning * Gate 2: Component and material repair * Gate 3: Engine re-assembly Appendix A contains a preliminary assessment of one GTF facility, which could serve as a starting point for investigation and analysis of network-wide capacity for Gate 1 and Gate 3 processes.
1.3. Background
1.3.1. Engine Development and Aerospace Industry Background
Back on a December day in 1903, Wilbur and Orville Wright piloted their Wright Flyer in Kitty Hawk, NC, proving that an individual could control and sustain flight in a powered vehicle. New innovations, design and performance improvements, manufacturing progress, and engineering developments continued to drive advances in the field of powered flight through World War I and World War II. However, the advent of the jet engine in the mid-1 930s would change everything'
Throughout most of World War II, military aircraft were powered by piston engines driving a propeller, limiting both their speed and range. However, with the first turbojet engines being tested independently by Hans von Ohain of Germany and Frank Whittle of Great Britain in the late 1930s and early 1940s, aircraft would become capable of sustained flight and flight at supersonic speeds2 . These new jet engines incorporated a compressor, combustor, single- stage turbine, and a nozzle to create the hot, high-pressure gases that would provide increased thrust for the airplane.
Below, Figure 1 shows the evolution of early turbojets into today's geared turbofan architecture. Early turbojet engines injected incoming air directly into the compressor, whereas later turbofan engines utilized a large front fan to move a larger amount of air more slowly, increasing the efficiency of the engine. In the turbofan model, the fan turns at the same rotational speed as the low speed turbine, which forces either the fan to rotate faster than its optimal speed or the low speed turbine to rotate more slowly than its optimal speed. The latest design change incorporates a gearbox which decouples the front fan and low speed turbine, allowing the fan to
I Weiss and Amir, "Aerospace Industry" 2 Ibid
Page 113 rotate more slowly. This slower fan speed further increases engine efficiency. In the geared turbofan model, each module can rotate at its optimal speed independently of the other modules.
Three jet ages Compressor Combustion Turbine TURBETiamber In emntjetslncomigair was directed lothe an ig.ited LogRTHRUS and drive a turbioc
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swaunithe'cof GEARED TURBOFAN A gearbou Ams a bigger fan to rotate more sowly than ofTte rAIGFLOW TpaUSngn r m .st engine, to puatn none largr Volume of a ni aroundtlsejetscore
Figure 1: Jet Engine Development'
The current aircraft engine design, production, and maintenance environment is dominated by three main companies, all concurrently looking for the newest technology to grow their market share in the highly competitive aircraft engine market. These companies are General Electric (GE), Rolls-Royce (RR), and Pratt and Whitney (PW).
GE Aviation, a subsidiary of GE based in Evendale, OH, first tested the waters in the aviation industry during World War 11 by developing and testing a turbosupercharged engine to fly higher and faster than the competition. GE Aviation is now a global organization providing commercial and military jet engines, components, and services, gas turbines for marine operations, and integrated maintenance services4 with revenues of $26.3B and profits of $6.1 B reported in 20165. Several of the company's engine offerings include the CF6 model installed on Boeing 747 / 767 aircraft, a military version of the CFM56-2 installed on the KC-135 Tanker aircraft, the GE90 installed on the Boeing 777 aircraft (identified as the "world's most powerful jet engine"), and the GEnx powering Boeing's Dreamliner aircraft. Below in Figure 2 are images of the GE Lockland facility and their CF6 engine model.
3 The Engineer, "Meet PurePower - A Quieter and More Efficient Jet Engine" 4 General Electric, "Aviation History" 5 General Electric, 2017
Page 114 Figure 2: GE's Lockland Plant and the CF6 Engine
Rolls-Royce emerged in 1884 as a car manufacturer selling cars in the London area and expanded into aircraft engines in World War I with the production of the Eagle engine in 1914. Today, RR designs and manufactures commercial and military jet engines and power systems for applications including aviation, marine, and energy uses 6. RR reported 2016 revenues of E13,783M and profits of E915M 7. Below in Figure 3 are images of the Eagle production facility and the Trent 1000 engine installed on the Boeing 787 Dreamliner aircraft. Other RR engine models offered include the Trent XWB engine designed for the Airbus A350 aircraft, the Trent 1000 engine offered for the Boeing 787 Dreamliner aircraft, and the MT30 marine engine powering several of the United States Navy's multi-mission destroyers. Additionally, RR is developing its own geared turbofan engine model, the UltraFan engine, which will use RR's new Power Gearbox8 and will likely compete directly with PW's GTF engine for customers who are looking for step-function increases in efficiency.
Figure 3: RR's Eagle Production Line and the Trent 1000 Engine
Pratt & Whitney Aircraft Company was founded in 1925 in Hartford, CT and revolutionized the aviation industry with the air-cooled Wasp engine, the engine that would become the go-to for Army Air Force and Navy fighter planes. In 1929, Pratt and Whitney joined United Aircraft & Transport Corporation, which would later transform into United Technologies Corporation
6 Rolls-Royce, "Our History" 7 Rolls-Royce, 2017 8 Bennett, Jay, "Rolls-Royce Sets Record for Most Powerful Turbofan Gearbox In the World"
Page 115 (UTC), PW's parent organization'. In 2016, PW reported adjusted net sales of $15.1 B and adjusted operating profit of $1.8B1 0. In Figure 4 below are photos of the first Wasp engine and the newest commercial engine in production, the PW1 1 OG with Geared Turbofan Technology. Several other engines are also offered by PW and include the F1 35 engine for the F-35 Lightning fighter aircraft, the F117 installed on the C-17 Globemaster Ill military transport aircraft, the F1 19 installed on the F-22 Raptor fighter aircraft, and the GP7000 engine powering the Airbus A380 aircraft.
Figure 4: PW's Wasp Engine and PW11OOG GTF Engine
Once a new engine model has been selected for an airframe application and has been through the rigors of design and development, engineering analysis, ground and flight testing, and regulatory approval, the engine manufacturer begins production to meet both the airframer's engine quantity needs but also to enable spare engine delivery to the airline customer, if requested. Following delivery, management and maintenance of in-service engines shift from a production support group to an aftermarket support group.
1.3.2. Aftermarket Operations
Aftermarket Operations is an essential element in both an engine manufacturer's bottom line and in maintaining high customer satisfaction. Engine manufacturers will often sell new production engines at or below cost, depending instead on a customer's post-sale engine maintenance and spare parts needs to drive engine model profitability. Therefore, it is critical that an engine manufacturer's aftermarket organization is forward-thinking and agile, responsive and customer-focused, and consistent and dependable. Aftermarket Operations consists of three main areas of responsibility: MRO activities, spare parts support, and on-wing troubleshooting and customer support.
9 Pratt & Whitney, "Where We've Been" 10 United Technologies, 2017
Page 116 MRO Activities An engine can be removed from an aircraft for several reasons. First, unscheduled removals are the result of unforeseen events, such as Foreign Object Debris (FOD), unexpected component or piece-part failures, or in-flight issues requiring in-depth troubleshooting. Second, scheduled removals are planned by the airline in advance and can be due to life limited parts expiration and routine periodic maintenance for performance restoration.
Once the engine has been removed from the aircraft, it is shipped to an MRO facility for disassembly, inspection, repair, reassembly, and acceptance testing. Individual steps in this process are discussed in more detail in Section 1.3.4. This process from start to finish (induction to delivery) is managed by the aftermarket organization, and the group's primary goals are to maintain high-quality engine repair work and to exceed the customer's TAT and budget expectations.
Spare Parts Support When operating under extreme pressures and temperatures, engine components fail or start to degrade and will need to be reworked or replaced. Many engine Original Equipment Manufacturers (OEMs), such as PW and GE, have empowered teams within the organization to manage the available supply of spare parts to support those which need replacement either by an operator while the engine is on-wing or during an engine's visit at the repair station. Due to the lengthy manufacturing processes required to produce some of these complex, highly engineered parts, demand planning is critical to ensure that the right parts are available at the right time to support the repair effort. Data analytics and failure trending play a large role in effectively managing parts production and inventory levels to balance availability of parts with production and storage cost.
On-Wing Support In addition to providing the airline customer with scheduling support, spare parts, and overhaul services while the engine is off-wing, the OEM aftermarket organization also provides on-wing customer support through troubleshooting. This organization can deploy specialized field service representatives to the customer's location to perform activities such as internal borescope inspections, component removal and replacement, or engine troubleshooting assistance. These efforts are often aimed at preventing an unnecessary engine removal by addressing the operational issue while the engine is still installed on the aircraft.
Page 117 1.3.3. GTF Program History, Development, and Status
1.3.3.1. History and Development
International Aero Engine (IAE) is a global partnership consisting of PW, Japanese Aero Engine Corporation (JAEC), and MTU Aero Engines and is responsible for managing the sales, production, and aftermarket support of the legacy V2500 engine model. IAE's V2500 engine has been powering aircraft on worldwide routes for decades, with over 190 airlines and lessors operating this engine model. The V2500 engine is installed on the Airbus A320 family, MD-90, and KC390 aircraft and has been in operation for over 30 years". However, PW engineers knew that this engine family would eventually require a successor.
To regain market share from competitors and establish itself as a major player in the aircraft engine development field, PW looked to introduce a game-changer, an engine promising large step changes in performance and efficiency. PW invested 20 years and $1OB in the research and development, ground testing, and flight testing of what would become known as the Geared Turbofan TM, or PW1000G, engine12 . This engine was designed for the high-cycle, short-to- medium-haul market and would become one of two options for the new Airbus A320neo platform. Airbus was aiming to improve cost effectiveness and environmental impact with its new A320neo aircraft, and replacement engines also needed to meet these same high standards.
Likewise, Bombardier, Embraer, Russia's United Aircraft Corporation, and Mitsubishi have chosen the PW1OOOG engine family to power their newly introduced aircraft. The significant improvement in fuel efficiency, emissions, noise, and operating cost of the GTF engine is a benefit for airframe manufacturers looking to differentiate their product from that of the competition. Additionally, PW's ability to scale engine thrust to each aircraft application makes the GTF engine a good fit for each aircraft's targeted market14 .
1.3.3.2. Unique Features & Competitive Advantage
The GTF engine family was designed and built based on the traditional 2-spool engine architecture, with one high speed rotor and one low speed rotor. In previous 2-spool engine
1 International Aero Engines, "V2500 Engine" 12 Pratt & Whitney, "PurePower 100OG Engine" 13 Sato, Imamura, and Fujimura, "Development of the PW1 100G-JM Turbofan Engine" 14 Wright, Rich, "Flying Now: Geared Around a New Era of Flight"
Page 118 designs, the high speed rotor (tying together the High Pressure Compressor (HPC) and High Pressure Turbine (HPT)) rotates at around 10,000 rpm and the low speed rotor (linking the fan, Low Pressure Compressor (LPC), and Low Pressure Turbine (LPT)) rotates at a much slower 4,000 rpm. Figure 5 below shows a diagram of the traditional engine architecture 516 .
Figure 5: Conventional Engine Architecture 17
However, with this linked design, the overall engine efficiency suffers - the LPC and LPT would be more efficient operating at a higher rotational speed and the fan would be more efficient operating at a lower rotational speed. This inefficiency is solved with PW's GTF engine through the installation of the Fan Drive Gear System (FDGS). Figure 6 below shows the new geared design incorporated in PW's PW1000G GTF engine family.
Figure 6: Geared Turbofan Architecture18
The FDGS is a gearbox installed between the fan and the LPC, decoupling the two modules. This change in architecture allows the traditional low speed rotor (LPC and LPT) to rotate faster and the fan to rotate slower, gaining critical efficiencies from both modules. In the GTF, the fan 15 Wright, Rich, "PW1000G Engine" 16Wright, Rich, 17 "The GTF Engine" Pratt & Whitney PurePower Engine, "Pratt & Whitney PW1 O00GPurePower Engine How It Works" 18 Ibid
Page 119 rotates at approximately 3,000 rpm, the low speed rotor rotates at around 12,000 rpm, and the high speed rotor rotates at about 20,000 rpm. Combined with an increased fan diameter, the engine Bypass Ratio (BPR) is increased, allowing more air to be processed at a lower speed and increasing overall engine efficiency. A look at propulsive efficiency reveals the reasoning behind this change.
Propulsive Efficiency Propulsive efficiency is a comparison of the amount of power produced by the engine to the rate of kinetic energy generated. Higher efficiency corresponds to higher power produced for a certain rate of energy generated. The amount of power produced is the product of the engine thrust and the gas velocity. Engine thrust can be measured as the combination of the thrust created by movement of air through the engine core (7e), called core airflow, and the movement of air around the engine core (?fl), called bypass flow. Higher bypass flow corresponds to a higher BPR. Here, with the inlet and exhaust both relatively close to ambient pressure, the major element in creating engine thrust is the difference in momentum of the fluid between the core and fan exits (engine positions designated by the subscripts e and f, respectively) and the inlet or free stream (designated by the subscript o)19. Thrust can be expressed as 2 0:
F(thrust) = me * ve + BPR * ?lc * vf - 7o * vo
Power(engine) = F(thrust) *vo
The rate of kinetic energy produced is kE = * me * ve _ * 0 v,2. Combining these two equations yields the engine propulsive efficiency2122:
F(thrust) * v ij(propulsive) 0 = 1 - 2 1 - 2 V Me * V - -2* MO *V6
As shown in the above equations, propulsive efficiency can be improved by increasing thrust, and one option for achieving this goal is to increase the fan diameter. Increasing the diameter of the front fan increases the engine's BPR, allowing more air to be processed, and increases the
19 Spakovszky, Z, "Thermodynamics and Propulsion" 20 NASA, "Turbofan Thrust" 21 Kellogg, Erin C, "Internal Dynamics of the Short-Term Commercial Aircraft Engine Leasing Market" 22 lbid
Page | 20 size of the of area over which the inlet pressure changes. Likewise, the GTF engine model achieves its efficiency increase by increasing the fan diameter - more air is brought in - and by decreasing the rotational speed of the fan - moving the air more slowly. These efficiency improvements are made possible in the GTF engine through the incorporation of the FDGS to isolate the speed of the front fan from that of the low speed rotor, allowing each module to turn at its optimal speed.
In addition to the FDGS, PW has incorporated into the PW1OOOG GTF engine model newer, lightweight materials throughout the engine, reduced the total number of rotating parts and engine stages, and improved engine aerodynamics. This improved engine sustainability will bring increased savings to airline customers over the lifetime of the engine through reductions in fuel burn, emissions, noise footprint, and operating and maintenance costs.
Reduced Fuel Consumption In conjunction with the above equations, the increased propulsive efficiency through increased BPR of the lightweight fan, coupled with the utilization of lighter weight composite materials and fewer internal rotating parts, decreases overall engine weight and results in a reduction of fuel burn by approximately 16% compared to the traditional 2-spool engine model. At a time when fuel costs are a considerable proportion of an airline's operating costs, this savings that the GTF provides is a strong benefit proposition to airlines.
Cleaner Operation The new TALON X series combustor utilized in the GTF family provides substantial improvement over current combustor designs. This advanced combustor design utilizes a fuel- rich combustion zone and a lean-mixing zone, also called a Rich Quick Quench Lean (RQL) design. As shown in Figure 7 below, NOx emissions increase with increasing temperature and time; thus, reducing the temperature and time through quick quenching will reduce overall NOx emissions.
Page | 21 & Lean 200 Fuel FeRihMixingRich Combustion Lean Rich Combustion
Too Lean TimeTme to Bum 4 ms 100 z Engine 1 ms Average 1 ms Rich Quick Quench Lean (RQL) 0.3 ms Combustor Design 0 0.2 0.6 1 1.4 1.8 Equivalence Ratio - Fuel/Air El - Emission Index, grams NO, per kg of fuel Figure 7: TALON X Combustor
Additionally, with lower fuel consumption, total emissions of both C02 and NOx will decrease23 This new combustor design will reduce carbon emissions by 3,500 tons per aircraft per year and reduce NOx emissions to 50% below the CAEP/6 threshold.
Quieter Footprint The new GTF engine design incorporates several noise reduction technologies; among these are a lighter-weight, low speed fan made possible by the development of the FDGS and a high efficiency HPT module with improved aerodynamics. PW expects a reduction in aircraft noise footprint of approximately 50%-75%. See Figure 8 below for the GTF engine's reduced noise profile.
I Existing turbofan PurePower- PW1000G Engine Figure 8: GTF Noise Reduction
A lower noise profile provides benefits to both the airline operator and to the surrounding communities. Operator benefits include the potential for expanded airport operation and the
23 Epstein, Alan, "A Primer: Aircraft Emissions & Environmental Impact"
Page | 22 potential for extended curfew hours, lowered noise fees, and the utilization of more direct, optimized flight paths 2 4 .
Lower Operating Costs for Airlines Compared to conventional turbofans, the GTF engine will reduce overall engine operating costs by over $1 M per aircraft each year through extended operating times and longer time on-wing. These extended hours in flight can be tied to the new engine configuration including advanced HPT sealing, cooling, and durability and shaft-tied rotors in the newly-designed HPC. The GTF also incorporates higher cycle limit LLPs, easily accessible airfoils for borescope inspection, and fewer stages and fewer airfoils to reduce overall maintenance cost for airline operators 25.
1.3.3.3. Current Fleet and Customers
Initial commercial interest in the GTF engine family began in 2008 in the small aircraft (100-130 seats) market with the Mitsubishi Regional Jet (MRJ), where the company was looking for a "game changer" to increase competitiveness 26. This same market was also targeted by Bombardier and their new CSeries jet. PW aimed to use scaling of the engine core (HPC, Combustor, and HPT) to provide the adaptability to meet the required thrust rating for each of these applications. During the development and testing of the GTF model for these two customers, PW also found interest with Airbus, Irkut, and Embraer, further expanding the reach and benefit of the GTF with airframe manufacturers 27. Entry into Service (EIS) for the PWI 1 OOG-JM occurred in January 2016 with Lufthansa, and EIS for the PW1 500G occurred in July 2016 with Swiss Air2 .
PW currently has six engines in the GTF PW1OOOG family in service or under development, shown in Table 1. Table 1: GTF Family
Engine Model Airframe Example Airlines Status
PW1100G-JM Airbus A319neo Indigo, Go Air, jetBlue, LATAM, Certified and in Airbus A320neo Korean Air service Airbus A321 neo
24 Pratt & Whitney, "The PurePower PW1000G Engine: The Economic and Environmental Solution" 25lbid 26 Norris, Guy, "MRJ Is Breakthrough for P&W Geared Turbofan" 27 Polek, Gregory, "Pratt & Whitney Geared Turbofan Promises New Engine Dominance" 28 Bombardier, "SWISS Launches Revenue Service with State-of-the-Art Bombardier C Series Aircraft"
Page | 23 Engine Model Airframe Example Airlines Status
PW1200G Mitsubishi MRJ70 ANA, SkyWest, JAL Certified with Mitsubishi MRJ90 EIS estimated in 2018
PW140OG-JM* Irkut MC-21 Illyushin Airlines, Crecom, Certified with *GTF is one of Sberbank EIS estimated in two options 201829
PWI500G Bombardier Air Canada, Delta, Lufthansa, Certified and in CS100 Swiss Air service Bombardier CS300
PW1700G Embraer E195-E2 SkyWest, AerCap, Air Costa, PW1900G PW1900G Trans States certified30 PW1700G in testing EIS estimated in 2020
Currently, a fleet of over 400 engines is in operation with airline customers or held as spare engines, and production is continuing to increase to support upcoming aircraft deliveries. More than 8,000 GTF engines are now on order, including options and unannounced orders. 31
1.3.4. GTF Engine MRO Network
1.3.4.1. Overhaul / Repair Process
Once an engine is removed from an aircraft for maintenance, it is shipped to one of the approved MRO locations in the PW GTF network for repair or overhaul. The depth of the shop visit workscope depends on several factors including hours and cycles in service, required Airworthiness Directive compliance and service bulletin incorporation, component failures, and observed or predicted component wear. The repair process is divided into four gates. See Figure 9.
29 United Technologies, "FAA Certifies Pratt & Whitney's PurePower@ PW1400G-JM Engine to Power Irkut's MC-21 Aircraft" 30 Kjelgaard, Chris, "Pratt & Whitney Confident It Can Meet PW1OOOG Commitments" 31 Daddona, Patricia, "Pratt Hiring to Boost PurePower Output"
Page 124 - Pre-Induction - Disassembly - Repair - Assembly - Workscope Generation Cleaning - Parts Marshalling - Balancing - Borescope Inspection Inspection - Kitting - Test
Figure 9: Overhaul Process Steps Gate 0 comprises the pre-induction activities required to be completed before an engine officially inducts into the repair process at the DAT facility. These steps include analysis of the engine time in service and expected scope of repair required, listing of all modifications or Federal Aviation Administration (FAA)-required inspections, generation of the initial workscope, and accomplishment of the incoming borescope inspection. The borescope inspection is a detailed, stage-by-stage inspection of the internal pieces of the engine to gauge level of wear or deterioration, and it is following this inspection that the workscope can begin to creep. The borescope inspection can indicate that the initial workscope is acceptable or that additional, unexpected findings need to be addressed.
Gate 1 begins with disassembly of the engine and major engine modules to the extent required by the workscope and level of repair required. Lighter workscopes require less disassembly and less part exposure, while heavier workscopes require a greater extent of disassembly. Following the disassembly process, parts, assemblies, and modules are routed for cleaning, if required, and for inspection. The inspection group performs detailed visual inspections of the parts and ensures serviceability in accordance with the engine manual wear limits. During inspection, parts can be tagged as serviceable to be used as-is or unserviceable and in need of further repair. The serviceable parts are routed to a storage area for safe-keeping until reassembly begins, and the unserviceable parts move to Gate 2 in the repair process.
Gate 2 requires that all unserviceable parts be routed to an internal shop for processing, to an external supplier for repair or rework, or to the personnel responsible for procuring new parts if the part was deemed to be unrepairable. These repair parts could require processes such as blending, modification, heat treating, or re-finishing. Depending on the specific DAT's capabilities list, the part could be processed either internally at a DAT back-shop or at an external supplier. Once the repair is complete, the part is inspected to ensure conformance to the engine manual limits, certified as serviceable, and returned to the storage area to await reassembly. The collection of parts required for a certain engine serial number is a process
Page | 25 known as marshalling, and parts are marshalled and moved to the storage area as they return from repair. Lastly, high utilization parts that are replaced at each engine shop visit, such as consumables, seals, and gaskets can be kitted together early in the process to be ready when Gate 3 begins.
Gate 3 consists of the engine reassembly processes and engine testing. Reassembly involves both reassembly of piece-parts and assemblies into the major engine modules and the reassembly of the modules into the complete engine. Also included in this gate are activities such as stacking and run-out of rotating groups and dynamic balancing of rotating parts. Once reassembly is complete, the engine is placed into a correlated and approved test cell to confirm the engine's delivered post-repair performance matches the performance certified for the engine model and expected by the customer. This is an essential step in the repair process to verify performance requirements and ensure customer safety. Depending on the engine model, testing procedures required, and troubleshooting needed, this testing process can take anywhere from one hour to several shifts.
Figure 10 below shows the sequence of activities and gates in the repair process, expected TAT for each gate, and major milestones in the engine repair process.
Figure 10: Gates, Milestones, and TAT for Repair Process
In the above figure, Gate 4 can be used to represent the post-test activities required to return the engine to the customer, such as EBU completion and shipment from the DAT facility to the customer's facility. The timely completion of activities in each gate is critical to ensure that the engine moves smoothly through the shop and that the overall process TAT meets the customer's demand. For light workscopes, an average TAT goal is 20 days and for heavy
Page | 26
I workscopes, the average TAT goal is 85 days. In aggregate, the overall TAT goal is to return the engine, regardless of workscope, to the customer in under 90 days.
1.3.4.2. GTF MRO Partners / Suppliers
In the current GTF MRO network, four DAT repair stations are certified to perform work on the GTF engine family: * PW Columbus Engine Center (CEC) in Columbus, GA, United States * MTU Aero Engines in Hannover, Germany * Ishikawajima-Harima Heavy Industries (IHI) Mizuho in Tachikawa, Japan * Lufthansa Technik (LHT) in Hamburg, Germany
Additionally, Eagle Services Asia (ESA) in Singapore will join the GTF network in early 2019 to provide MRO services to GTF airline customers in Asia. Below in Figure 11 is a map showing the current MRO facilities for the GTF program.
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Page 127 2. Methods 2.1. Literature Search
In order to analyze test facility capacity and assess appropriate service levels and capacity buffer, the single server queue model was found to be a useful starting point for modeling the MRO engine testing environment. A M/M/1 queue can be used to show the correlation between capacity utilization and average number of customers in the queue. The average number of customers waiting, or queue length, can be viewed as similar to service level, with a longer queue length corresponding to longer wait time and poor service. Gosavi (n.d.) shows that
Average Queue Length = Lq = p2 - p), where p = = mean arrival rate represents capacity It mean service rate utilization. As shown in Figure 12 below, this relationship between capacity utilization and average queue length is highly nonlinear, and as capacity utilization exceeds 80%, average queue length and average wait time increase exponentially.
Higher Utilization Leads to Much Higher Queue Length & Wait Time
0) ) C -j a) a 0) a)
0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Capacity Utilization
Figure 12: Queue Length vs. Capacity Utilization
To achieve a higher level of service (or shorter queue length), a lower capacity utilization is needed, and the mean service rate must be much larger than the mean arrival rate. For the GTF Engine Testing analysis, capacity utilization of 80% was assumed to be the threshold at which the capacity of the engine test network would no longer be sufficient to meet the customer's needs and capacity expansion studies needed to be initiated.
Using the completed capacity model to predict future capacity and to provide planning recommendations required several aspects of shop operations to be considered. Wibowo
Page 128 _M
(2016) developed a useful framework, shown in Figure 13, for integrating customer utilization data with the MRO's production capabilities in order to reduce risk and uncertainty in the repair process.
FMmm M* OW s~ hvewd Output:P
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lowa
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Figure 13: MRO Conceptual Framework
Reducing uncertainty by using engine health monitoring data and customer-provided flight plans and flight data yielded a more accurate repair demand profile for the engine MRO, allowing for improved capacity planning and reduced TAT. Increased shop capacity worked to reduce TAT and more quickly return assets to customers. This framework shifted decision-making from experience-based intuition to data-based analysis, also enabling better translation of demand planning estimates into resource requirements. As the GTF MRO network matures and additional operational data is collected, this framework would be useful for reducing risk to shop TAT due to capacity-demand mismatch, ensuring adequate capacity network-wide to include surge capabilities, and assessing the need for adding capacity in the network.
Likewise, Srikar (1989) created a model to represent product flow through an aircraft landing gear shop. This model was found to be useful for modeling flow of a product through various stages of the shop and considering constrained resources or bottlenecks. The key drivers of TAT in the shop environment were identified as the effectiveness of product flow from one task to the next, work content and extent of work required by the customer, and the availability of necessary resources. While this study was completed using a landing gear facility, the useful translation to engine testing processes was clear. This case study was found to be an effective tool for thinking about the impact of flow lines, engine testing resource availability (such as test
Page 129 cells and duct sets), and workscope differences during the engine testing processes and the impact of these variables on the overall engine test TAT.
Learning curves were found to be an important aspect in capacity planning, as employees realized effective capacity gains through more efficient completion of engine testing tasks over time. Hartley (1965) stated that the time required to complete a specific task will decrease each time the process is worked, with each successive decrease in cycle time smaller than the previous until a steady state was reached. These reductions in manpower were larger at the beginning of a new program when the process was still unfamiliar and there were increased opportunities to improve. Over time, employees became more acquainted and more efficient with approved processes, resulting in progressively lower cycle times. These lower cycle times could be translated into an increase in shop capacity.
2.2. In-Shop Investigation and Interviews
A key element in investigating the current capacity of each network DAT shop was an in-shop tour to explore the overall layout of the facility, tooling availability and placement, and both intended and actual shop flow. Planned and desired layout changes were also more easily viewed and analyzed in-person.
The case study is limited to the processes contained in Gate 3 Engine Testing. At each facility, the number of cells or "bays" available, specific work flowing through each bay, number of shifts and hours per shift worked, shared resources, and number of test cells and duct sets available were identified and documented. Additionally, expected operational readiness dates for any bays or resources in work were also listed.
A second critical element in determining a facility's capacity was interviewing key shop personnel. These contacts were essential in ensuring accurate understanding of the ways engine bays are used, how manpower and labor are spread among repair processes or are shared with other engine programs, and for providing updated process times as process improvements and turn-time reductions are implemented. During this case study, operations managers and cell leaders were the primary interviewees since they were most closely tied to the daily work being done on the shop floor. Discussions were also held with process engineers, inspectors, mechanics, and quality personnel when available.
Page 1 30 2.3. Capacity Model Development Overview
In order to compile data collected on process times, tooling, engine bays, and manpower during the in-shop investigation and interviews, a capacity model based in Excel was utilized, in partnership with the PW Enterprise Capacity and Material Planning Strategy (ECMPS) group. Soon, this model will be converted into an online portal for ease of data update and creation of capacity analysis charts. Details of the calculations performed in this Excel model are discussed in Section 3.
The first set of inputs into the demand model were shop specific and depended on the size and throughput of the facility. Data collected through the facility walk-through and interviews included the number of engine prep bays and test cells, number of shifts worked, hours worked per shift, regular work schedules or alternate work schedules, and process times for each of the major process steps.
Next, the estimated shop visit demand data was needed to compare the percent of capacity utilized to meet the anticipated demand and the total capacity of the DAT. The demand data used in this capacity model was provided by the PW ECMPS group and was considered the official estimate for demand planning purposes.
2.4. Production Readiness Decision Chart
The final deliverable from this framework and case study application was a Production Readiness Decision Chart (PRDC) showing the overall network capacity for the Engine Test processes between 2018 and 2026. See Section 5.2 for completed PRDCs. These PRDCs identified where the estimated shop visit demand outpaced the currently available network capacity, necessitating the construction of additional test facilities or the spool-up of additional GTF program test partners.
The decision milestones included on the chart showed several items of interest. First, the graphic illustrated the estimated timeframe where current capacity will no longer fully satisfy the forecasted shop visit demand. This was the point at which the aggregate "utilized capacity" bar exceeded the maximum capacity line of the network (where all facilities are operating at 100% capacity utilization) and where increased capacity needed to be online and operational. However, as discussed above in Section 2.1, an adequate buffer of capacity needed to be considered to ensure service level met the needs of GTF customers. This buffer was applied by
Page |31 reducing the acceptable capacity level either at the shop level or the network level to a maximum of 80% utilization, and this new threshold was used as the indicator that additional capacity needed to be sourced. Second, the chart looked back in time and identified the point where any additional test facilities needed to be completed to allow sufficient time for engine correlation (see Section 4 for a description of engine test correlation processes), troubleshooting, manpower hiring, and training. Third, based on typical construction and test cell equipment turn times, the PRDC showed in what timeframe the construction of a new test cell needed to begin or additional test cell equipment needed to be on contract. Lastly, the chart showed when the funding process needed to begin to have funds in place to start the capacity ramp-up.
Page | 32 3. Capacity Model Development - Gate 3 Engine Testing The Engine Testing capacity model was created using an Excel-based tool to collect engine DAT facility process times and resources available and to analyze capacity at both the facility level and the network-wide level.
The first data set collected for each engine testing site was the work schedule, consisting of the number of days worked per month, the number of hours worked per shift, and the distribution of shifts available. These values were used to calculate the total available capacity per facility, as shown below. Figure 14 shows the format for gathering the days worked per month - these account for national and company holidays and for weekends worked.
Calendar Year Available WorkN DaystJan Feb Mar r IMa Jun IJLAIuQ IeOct INov IDec 18 15 18 17 171 18118 1 26 19 16 12
Calendar Year AvailableWokMng Days Jan Feb Mar M ClendA Ye I Oct Nov Dec 12 12 12 12 1212 12 12 12 12 12 Figure 14: Example Format for Working Days Documentation
Since some facilities may work varying schedules due to differences in country location (and thus national holidays), the tool was designed to allow for differing work schedules per site. This format is also useful for identifying and accounting for facilities where an alternate work schedule from Friday through Sunday is utilized in addition to the standard Monday through Thursday work schedule.
Similarly, the time available per shift was documented for each testing facility. This value represents the amount of time for each shift the test resources are being utilized to complete engine test processes. The chart was an opportunity to easily identify differences in work shifts per site. For example, some shops work longer shifts (10 hours) versus other sites where the standard shift is 8 hours. The time available was calculated by subtracting the 30-minute lunch period from the total shift time, then converting to total minutes available. The total time available per month per facility was found by summing the time available per shift for each day (considering both standard work schedules and alternate work schedules) and multiplying by the number of days worked per month. This value represents the total time available at each site per resource. A resource here was a combined test cell and duct set. Typically, 3-4
Page 133 employees were required to prepare the engine for test and to run the test. In this case, an adequate number of employees is available, and the constraining resource was the number of test cells and duct sets available. If a facility had multiple resources (for example, more than one test cell or complete duct set), this time available would be multiplied by the number of available resources to obtain the total capacity available for that site for the given month, shown in Figure 15.
- Tavati,std shift,site min = (Lengthstd shift(hr) - Lengthlunch(hr)) * 60
(in Tavati,altshif t,site = Lengthalt shif t (hr) - Lengthlunch (hr)) 60 (hr
Tavail,site,eff - * std work days; +Tmin) (Tavail,std shift,site ((min) y month Tavawi,at shif t,site (d ay days) (# of resources available) # alt workmonth
Time Av kilble
Ammbbe aialel An-Ible Aibble Avaible A ibnle Gate 'nfration Gate 3 Repai Site 1 Test 450 450 330 Gate 3 ReOr Site 2 Teat 5707 Gate3 Re r Site3 Test 450 450 __ Gate 3 Re a Site4 Teat 450 450 Gate 3 Repair Site 5 Test 570 570 690 Gate 3 Repair Site 6 Test 450 450 Gate 3 Repair Site 7 Test 450 Figure 15: Time Available per Shift per Site
To account for time spent on breaks or in meetings, time to locate tools or procedures, or unproductive work time, a value to represent site efficiency was also included in the calculation of total time available per site. See Figures 16 and 17 below.
Tavaii,site = Tavail,site,eff * Efficiency
Sire J Oper I Work Scope Jan Feb Mar Apr May Jun JAd Aug Repair Sre1 Effiolenoc, BOX BOX BOX BO% BOX BOX BOX BOX Repair Sie 2 Efficienoy 80% BOX M %%B0A 8M% Repair Sie 3 Efficienay BOX BOX MV. BX X BOX owl OW. BOX Repair Ske 4 Effilenot BOX OW SIMO WB BOX 80% amX OW Repair Sre 5 Effilcienoy WOX BO X M , 80 my. 80% 0B0% OX Repair Ske Efficienoy 80% BOX I__ m %- % ___ II_%_ Repair Sie 7 Effloleno, 80% WOX IOX BOX BOXW IX BOX BOX Figure 16: Efficiency over Time per Site
Page | 34 These efficiencies were listed over time and could be updated as sites moved down the learning curve from the initial setup stage when inefficiencies were high to the experienced test cell and test operator stage where operations ran more smoothly. These improvements in labor efficiency with time could also be used to represent the end of a training period where more experienced operators will be dedicated full-time to running the test processes instead of training new teammates.
___ 2017 Daily Time Daily Time Site Process Infornatlon Available Avalable Jan Feb Mar Apr May Jun Jul Mon-Thurs Fri-Sun Re-a-ia000- 0 1 0 1 1 0 I 16001 110 106000111600 Repair Site 2 Test 154 0 2710 2464 2834 2484 2834 2710 2464 Repair Ste 3 Test 57 0 0 0 0 0 0 0 0 Repair Ste4 Teat 577 0 10156 9232 10817 9232 10617 10155 9232 Repi Skte 6 Test 885 300 0 0 0 0 0 R r Sike 6 Teat 0 0 0 0 0 0 0 0 0 Repair Site 7 Teat 0 0 0 0 0 0 0 0 0 Figure 17: Total Time Available per Month per Site
Secondly, the number of resources or work stations available was documented for each test facility. See Figure 18. For the test process, these resources included the engine test cell and the support equipment or duct sets. The tool was designed to allow for easy incorporation of additional test cells once constructed or additional duct sets once procured without much manual manipulation.
Pmocess/slte 2~ IJan Feb M AprI MeY Jun Ju' Repair Ste I Duct 4 Mot- Repair Ste 2 Duct I Repair Site 3 Duct 0 Repair Site 4 Duct 1 Repair Site 5 Duct 0 Repair Ste 6 Duct 0 Repair Site 7 Duct 0 Repair Site I Test 4 Repair Site 2 Test 1 7 Repair Site 3 Test 0 Repair Site 4 Test I Repair Sie 5 Test 0 Repair Ste 6 Test 0 lRepair Ste 7 Test 0 Figure 18: Resources Available per Site
The entries shown in the green shaded boxes indicate the addition of another resource during the specific month. Here, Repair Site 3 will be adding operational capability in January 2018 with one new test cell and one new duct set. This chart also allowed for what-if scenario planning where additional resources could be added in a specific timeframe in the future to investigate the impact of resource addition on the total capacity of the network.
Page | 35 The third set of data collected for the engine test procedure was the cycle time to complete the engine test process. This time included the activities required to prepare an engine for test, perform the test process, and remove the duct set following a successful test.
min Trequired = (Tdress(hr) + Ttest(hr) + Tstrip (hr)) * (60 -)
This section of the capacity tool provided several useful benefits. Since the test process time could vary depending on thrust class, the ability to differentiate cycle time based on 30K, 24K, 17K, or the F1 17 engine model allowed more accurate representation of the facility's capacity. Differences in cycle times can also be observed across sites because of learning curve differences during start-up and experience levels of the test operators. The tool incorporated the ability to easily reduce cycle time across all shops (network-wide improvement in process steps or new software push) or at individual facilities due to the procurement of an additional duct set, shown in Figures 19 and 20 below.
Tcycle,Light WS required,Light WS Treduction,Light WS
Tcycle,Heavy wS = Trequired,HeavyWS Treduction,Heavy WS
Operation Pre Testj Post CT Min.l Jan Feb Mar A Jun Jul Gate 3 30K Test 1000 368 1736 Gate 3 24K SIte I Test 368 1000 368 1736 Gate 3 17K Test 368 10001 368 1736 Gate 3 1 F17 Test 368j32 368 7681 ^36i~ 1-36 Gate 3 I 3oK Tes 1 Gate 3 2 2 Test 368 1000 368 1736 Gate 3 17K Test 3I 1000 368 17361 Gate 3 F117 Test 13681321368 I 7RR Figure 19: Light/Medium Workscope Cycle Times and Reductions
Gate Operation Dress Test Strip CT Min. Jan Feb Mar A w Jun JUl A Oct Gae 3 30K Test 1000 11 1242: 450 Gate 3 24K Test 127 1000 115 12421 469 Gite3 h 1 17K Test 127 1000 115 1242 ______469 Gate 3 17 Test 127 35 115 277 Gate 3 30K Test 1000 115 1242 7 7 460 Gete3 2aK Test 127 1000 115 1242 460 Gate 3 lix Test 127 1000 115 1242 t Gate 3 m7 Test 127 35 115 277 1 1 Figure 20: Heavy MTS Workscope Cycle Times and Reductions
Lastly, in Figure 21, the tool differentiated between the cycle time for heavy Motor to Start (MTS) workscopes and light or medium workscopes by incorporating the difference in cycle times between the two processes and the percentage of each workscope expected for a given calendar year. The below table indicates that current estimates show all F1 17 repairs as heavy
Page 1 36 shop visits and the remaining thrust classes estimated to require 50% heavy shop visits and 50% light or medium workscopes from 2018 through 2026. These values could easily be updated as the program progresses and as requirements change.
Site Prorm 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 % % % % % I% % % % % 30K 50% 50% 50% 50% 50% 50% 50% 50% 50% 50% 24K 50% 50% 50% 50% 50% 50% 50% 50% 50% 50% 17K 50% 50% 50% 50% 50% 50% 50% 50% 50% 50% u. F117 100% 100% 100% 100% 100% 100% 100% 100% 100% 100% 30K 50% 50% 50% 50% 50% 50% 50% 50% 50% 50% 24K 50% 50% 50% 50% 50% 50% 50% 50% 50% 50% 17K 50% 50% 50% 50% 50% 50% 50% 50%50%50% Fil7 0% 0% 0% 0% 0% 0% 0% 0% 0% _% Figure 21: Input Table for Workscope Percentages
Following the completion of the process data collection from each site, the remaining data required was the shop visit demand forecast over the period being analyzed. The demand forecast used in this case study was provided by PW's ECMPS group and identified the total number of shop visits for a given engine model (ex. for the PW11 OOG-JM model) which was aggregated to reflect demand for a specific thrust class (ex. 30K, which consists of the PW11 OOG and PW1400G models). A monthly demand forecast was found by assuming that the demand will materialize evenly over the 12 months of each year, or that there are no seasonal effects or months where higher than usual demand is observed.
However, this monthly estimate did not identify the number of repairs to be performed by each facility. A percentage of "market share" was used to allocate the total number of shop visits to the individual facilities based on their current workload and expected future workload. Below in Figure 22 is an example of the market share input table for the heavy workscope. These values can be updated as new facilities come online or as work is shifted from one facility to another. The areas shaded in red represent sites which are not expected to be operational for a given year - the cells are shaded yellow once the site comes online and can begin accepting engine test work.
Page 137 Skte PrOgraM 12017120181201912020120211202212023122 2025 2026 Ful WoekScp 30K 40% 0% 0% 0% 0% 0% 0% 0% 0/ 0% Ste 1 24K 0% 0% 0% 0% 0% 0% 0% 0% ox 17K 0% I% 0% 0% 0% 0% 0% 0% 0% 0% F11 0% 0% 0% 0% 0% 0% 0% 0% 0% 0x 30K 20/ 15% 1x 15% 5x15x 15% 15y 15x 15% Ste 2 24K 0% 0% 0% 0% 0/ 0% 0% 0V 0% 0% 17K 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% F11 0/ 0% 0y 0% 0% 0M 0% 0% O 0% 30K 25% 20% 20% 20% 20% 20% 20% 20% 20% Ste 3 24K 0% 0% 0% 0% 0% 0% 0% 0% 0% IK 0% 0% 0% 0% 0% 0% 0V 0% 0% F11 0% 0% 0% 0% 0% 0% 0% 0% 0V 30K 40% 25% 20% 20% 20% 20% 20% 20% 20% 20/ Ske 4 24K 0% 0% 0% 0% 0% 0% 0% 0% 0% 0% 17K 0% 0% 0% 0r 0% 0% V. 0% 0% 0/ F1T 0% 0% 0% 0% 0% 0% 0% 0% 0% 0/ 30K . 35% 35% 35% 35% 35v 35% 35% 35Y My. Ste 5 24K S xo 0%0% 0% 0% 0% 0r 0%0% 1K .] ox 0% 0% o/ 0% 0% 0% 0% 0/ F11 Ox 0% 0% 0% 0% 0% 0x 30K m- -. 10% 10% 10% 10% 10% 10% 10% 10% Ste 6 24K T 0% 0% 0% 0% N% 0% 0% Ov 17K 0% o% 0% 0%0% 0% 0% 0 Fill fk 1 x0/ ox 0%0% 0% 0/
Stl24K S. g.R 0 & S W iK e Figure 22: Market Share per Year by Site
An example of the calculation for the monthly demand for Repair Site 1 for January 2017 is shown below with equations. These equations were repeated for each thrust class and month at each facility to show the total shop visit demand per site per thrust class. Once the required number of shop visits per workscope level, thrust level, and site were determined based on the demand forecast, the required minutes to complete these repairs were calculated.
Heavy WS Monthly Demand3 0K,Site1,JAN 17 (# shop visits) = Total Monthly KJAN Demand3 17 * WS %Heavy ws * Market Sharesitel,20 1 7
Light WS Monthly Demand3 K,Site1,JAN 17 (# shop visits) = Total Monthly Demand30K,JAN 17 * WS %Light WS * Market Sharesite1,2017
Heavy WS Capacity Required30K,Site1jAN 17 (min) = Heavy WS Monthly Demand30K,Site1,JAN 17 * Cycle Timeite,30K,JAN 17,Heavy WS
Light WS Capacity Require d3K,Sitel,JAN 17 (min) = Light WS Monthly Demand30K,Site1,JAN 17 * Cycle Timeite,30K,JAN 17,Light WS
Lastly, to create the desired capacity analysis charts, the utilized capacity (capacity required to meet the estimated demand) was converted to a percentage of the total capacity available per test facility.
% Capacity Utilized30K,Sitel,JAN 17,Heavy WS Heavy WS Capacity Required30K,Site1jAN 1 7 (min) Tavail,site 100%
Page | 38 % Capacity Utilized30K,Sitel,JAN 17,Light WS Light WS Capacity Required30,Site,JAN (min) 17 * 100% Tavail,site
These estimates of capacity required per workscope level were aggregated into a total percent of capacity utilized for each site for the given month and thrust class of engine.
% Capacity Utilized3 oK,Site1,JAN 17 = % Capacity Utilized3oK,Site,JAN 17,Heavy WS
+ % Capacity Utilized3 0K,Site,JAN 17,Light WS
The percent capacity utilized for each site was shown as a bar chart (as shown below in Section 4.4.2) and analyzed for trends over time to assess when the estimated demand outpaced the available capacity at each facility based on currently planned expansions and equipment procurements. If the demand was found to exceed the available capacity, a new test cell could be constructed, additional ducts sets could be procured, or work could be shifted within the network if other facilities have available capacity. To assess capacity at a network level, each facility's capacity utilized bar was shown as a combined, stacked bar chart and compared to the maximum capacity available network-wide. If the total capacity of the network was insufficient to meet the predicted demand, PW would need to build new facilities, procure additional equipment, or onboard new partners to share in the work load. Additionally, the estimates for shop visit demand could be verified and assumptions validated to ensure the most accurate forecast available was being utilized.
For this case study analysis, the capacity tool was initially developed and refined using the 2018-2020 timeframe for the 30K thrust class only and was then expanded to show the predicted capacity through 2026 for 30K engines. This analysis tool could also be modified to show capacity for certain engine models or for the entire network covering all engine models. This iteration of the tool will be useful as additional engine models come online and begin to absorb some of the available network capacity.
Page | 39 4. Gate 3 Engine Testing Capacity and Gap Analysis The case study analysis focused on characterizing both the current and planned capacity of the GTF MRO network to perform post-repair engine testing. Once the subject engine is reassembled following the repair process, it must be tested in accordance with PW-approved procedures to ensure the engine's performance, once re-installed, will meet industry standards. To be approved to perform testing, a site must first construct an engine test cell and procure the needed test fixtures, instrumentation, and duct sets. Following completion of test cell construction, the cell must be correlated for each individual engine type the facility intends to test. Correlation is completed by first testing a specific serial number engine in a previously- correlated and approved cell. This same engine is then tested in the new test cell and the data from the new test cell is compared to the data from the approved cell. Differences in data points are analyzed, changes are made to the new test cell to more closely align the data, and correction factors are developed to ensure the same performance is observed in each test cell. This correlation process provides any needed correction factors to yield accurate performance data and to ensure the new test cell measures test parameters accurately.
Due to the long lead times for building and correlating a new test cell and procuring the required support equipment, Gate 3 Testing was one of the most critical areas of the engine repair process needing capacity analysis. Inadequate capacity in this Gate would significantly impact the return to service of a newly repaired engine and would leave customers with grounded airplanes or reduced operations.
The total time required for engine testing depended on the level of repair or overhaul workscope that was performed while in the shop - heavier workscopes with a deeper level of repair (more parts exposed, repaired, or replaced) required a longer, more comprehensive test procedure while a lighter workscope (for example, a hospital visit or surgical strike) might not have driven the same in-depth test procedure. The lighter workscope engine repairs typically required less than a single shift in the test cell, while heavier workscope repairs can require multiple shifts of test time in the test cell. Gaining an accurate characterization of the expected distribution of workscopes was a critical component in modeling and predicting the amount of time needed each month or quarter in each test cell.
A second driver of expanded time in the test cell was a turn-back. This situation occurred when an aspect of the engine's build or performance did not meet the required standard and the
Page |40 engine failed the test. Usually, the engine returned to the shop for the abnormality to be resolved; then the engine was transported back to the test cell for re-testing. These scenarios placed additional strain on shop personnel and caused significant downstream delays of current work in process. However, at PW on the GTF program, turn-back rate is low, with a very high percentage of engines successfully completing the test procedures on the first pass.
4.1. Current Facilities / Test Cells and Facilities In-Work
In the GTF MRO network, several facilities were found to have the capability to perform engine testing and several more were working toward operational readiness. Below in Figure 23 and Figure 24 are several images of a completed, in-service engine test cell.
2 P
Figure 23: PW Test Facility in Middletown, CT 32,33
Figure 24: MTU Test Cell in Hannover, Germany4,35
Table 2 below shows the current sites which are currently approved and performing engine testing.
32 Minter, Steve, "Pratt & Whitney Builds for the Future" 33 Eckel, "Jet Engine Test Cells and Gas Turbine Silencers" 34 Pratt & Whitney, "MTU Capacity Analysis, REV A" 35 MTUAeroEngines, "Ready for the heavyweight: GE90 test runs at the test cell at MTU Maintenance in Hannover"
Page | 41 Table 2: GTF Test Cells Available Facility Models Number Comments of Cells Repair Site 1 PWI 1 OG 4 * No longer performing MRO PW1 500 GTF test after Jan 2018 Repair Site 2 PW11 OOG 2 * 2 cells total but other customer work performed Not solely dedicated to GTF testing Repair Site 3 PW11OOG 1
As new engine production ramps so too will the number of shop visits required each year and the number of engine tests required. Several sites were building facilities and finalizing approval and certification to be able to support GTF engine testing following overhaul or repair. These are listed in Table 3.
Table 3: GTF Test Cells In-Work Facility Model(s) Number Date Operational of Cells Repair Site 4 PW1100G 2 * January 2018 PW1 500 9 (1) cell for GTF and (1) for others Repair Site 5 PW110OG 1 2018 PW1500 Repair Site 6 PW1100G 1 2019
4.2. Tooling - Duct Sets, Instrumentation
In addition to the test cell, several pieces of support equipment were also required to perform engine testing: the duct set (inlet, fan cowling, and exhaust - kept as a serial number matched set) and the instrumentation hardware and wiring (also called test cell slave equipment) required to collect test data points during the test procedure. Photos of the major duct set components required for the engine testing process are shown below in Figure 25.
Page 1 42 INC
4r
it S Figure 25: Duct Set Installed 36
Support equipment availability was an important factor to consider when analyzing capacity for Gate 3 Engine Testing - many of the elements cannot be shared between test cells or facilities and must be stored, used, and maintained as a matched set. Additionally, lead time to procure new equipment was often one year or more, driving the need to plan for and fund these procurements in advance. Lack of availability of test tooling can result in testing delays, longer repair TAT, and delay in returning the engine to the customer.
The current availability of these main test equipment pieces was reflected in Table 4 below. Also presented are the findings for projected duct set procurements to support future engine test requirements.
Table 4: GTF Duct Sets Available and On Order Facility Model(s) Current On Order I Duct Sets Available Date Repair Site 1 PW1 10OG 4 N/A Repair Site 2 PW11OOG 1 1 (2018) Repair Site 3 PW1 10OG 1 1 (2019) Repair Site 4 PW1 1OOG 0 2 (2018) PW1500 Repair Site 5 PW11 OG 0 1 (2019) PW1500 Repair Site 6 PW11 OOG 0 2 (2019)
4.3. Manpower / Labor
To perform the engine testing procedures, several individuals were required to be present. A test cell operator was responsible for performing the test procedure using the Test Instruction Specifications (a listing of PW-approved steps, performance tests, sequence, and test
36 Pratt & Whitney, "LHT Capacity Analysis, REV A"
Page | 43 parameters and outcomes) and for following the user interface instructions on the test cell software. These instructions in the test cell software were used to communicate with the engine through the Electronic Engine Control (EEC). The operator was also responsible for entering the test cell to make any required changes during the test cell run, such as adding more engine oil, raising or lowering the stand platform, or investigating abnormal readings.
A test engineer was also usually present, although this individual could be supporting multiple simultaneous engine tests. He/she may not be present in each test cell for the entire duration of the test run. The engineer's purpose was to be available to help resolve any engineering issues or questions that may arise during the test process.
A records quality person was required for the test run and was responsible for collecting the data print-outs of the test results as they became available, reviewing them for any abnormalities or inconsistencies, and ensuring they were included in the final binder of complete test support data.
During the analysis, manpower/labor was determined to not be a constraining resource in the process and was therefore not studied in depth. The bottleneck was identified as availability of tooling - the availability of the engine test cell and duct set - and the analysis focused on these aspects of Gate 3 Engine Testing.
4.4. Capacity per Shop and Conclusions
Shop test cell capacity was determined using a combination of personnel interviews, test cell tours, and process flowchart and cycle time data collection. An initial assumption was made that all shop test run times would be similar to the Middletown, CT test facility and this site would be used as the benchmark until a more substantial data set was available from each of the other approved facilities. This data set will be updated as more GTF engines complete the repair and testing processes and each shop's process times are recorded and validated by the PW ECMPS group or Industrial Engineering organization.
4.4.1. Assumptions
Several assumptions were built into this model and are discussed here. First, there were several internal sources for demand data, and one source was required to be chosen and used consistently throughout the analysis. The demand data used here was provided by PW's
Page 144 ECMPS group. Second, a baseline for available test sites and timing was presented and discussed with PW GTF leadership to ensure agreement before proceeding. The data used is shown in Table 5 below.
Table 5: GTF Test Sites and Timing Te-st Site Test CelS) OPErdtionad DUCI 7et(S) OperatiMROl 4-om0 017s site 1 (4) (4) B~ift20KMeRO4Q2017 SIte 2 (1) (1) (2)-Q1 2019 Site 3 (1) -012018 (1)- Q1 2018 Site 4 (2) (1) 2 cels spUt among multiple (1)- Q2 2018 customers site 5 (2) -Q1 2018 (2)- 012018 2 cells- (1) for 30K and (1) for all others Site 6 (1)--Q1 2019 (2)- Q12019 Site 7 TWD TOD optioni work TBD Optionbiwoik Third, a common understanding of baseline work schedules was also required for the analysis. Below in Table 6 is the current work schedule for each site (as of late 2017) as used in the capacity analysis.
Table 6: GTF Test Site Work Schedules
Site 1 (2) (1) Extng 30K MAO 4Q201 % Site 2 (1) (0) Ste 3 (1)- Q12018 (0) Entering into service Q1 2018 Site 4 (2) (0) Site 5 (2)- 012018 (1)- Q1 2018 Entering into servIce Q1 201$ Site 6 (1) - Q12019 (0) Ste?7 TB1 Tan Option in work
Fourth, since different repair workscopes require different tests to be conducted, an assumption on workscope mix was also made. A higher number of lighter workscopes, which require a shorter test time and fewer test procedures, would increase the facility's capacity; whereas a higher number of heavier workscopes, which require a longer test time and more test procedures, would reduce the facility's overall capacity. For 2018-2020, the workscope mix was assumed for all facilities to be 50% light workscopes (#3 Bearing and Combustor workscopes) and 50% heavy workscopes (MTS or overhaul).
Page | 45 Fifth, the model was designed to account for time during the work day spent on tasks other than engine test processes, such as lunch breaks, meetings, learning curves, and unscheduled cell downtime. This labor and process efficiency was estimated at 80% based on feedback from shop personnel and GTF leadership. This efficiency was expected to increase as operators become more familiar with the test processes and as cell improvements reduce downtime.
Sixth, several planned cycle time reductions were built into the model to represent the change in estimated process time to perform the heavy workscope engine test as improvements to the process were implemented. These are listed below. The capacity model was designed to easily accept additional cycle time reductions as improvements are implemented in the future. * 9 hours of reduction in October 2017 due to changes to the test software. * 9 hours of reduction in June 2018 due to the elimination of bowed rotor requirements. * 8.5 hours of reduction in June 2019 due to reduction of leaks, vibrations, and component removal and replacement during test and due to test cell improvements.
An additional source of cycle time reduction incorporated into the model was the procurement of an additional duct set. With one test cell and two duct sets, the facility can prepare and test the first engine (using the first duct set) and simultaneously prepare the second engine for test (using the second duct set). When the first engine completes the test procedures, the second engine can immediately be moved into the cell for test, removing approximately 6 hours of duct set installation time since the work was performed concurrently. The model accounted for this as a reduction in cycle time.
Lastly, for the 2018-2020 timeframe, market share for each shop was approximated to allocate repair work among the operational GTF repair facilities. The two charts in Figure 26 show how market share was assigned.
Page | 46 Market Share in 2018 Market Share in 2019-2020
15%1 ste5 %Ste 5 a S~ea Ste 43
2%Ste 2 2a Site 6
Figure 26: Market Share through 2020
4.4.2. Capacity Model Results
Once the above assumptions, demand data, and process time data were built into the capacity model, the network's ability to meet customer demand was analyzed and the timeframe by which additional test capacity should be online to meet future estimated demand was identified. A useful assessment of the validity of the tool's results would be to compare actual 2017 or 2018 repair delivery data (once available) to the model's prediction. In the future, this comparison would provide useful insight into assumptions that need to be adjusted or efficiency estimates that may have been too optimistic. Additionally, network-wide capacity should also increase over time as the program moves down the technical learning curve - identifying technical issues and implementing design changes to prevent future removals thus decreasing the anticipated future shop visit demand.
The period from 2018-2020 was used as a starting point since that timeframe represents the most accurate process time data and demand estimates. The tool was then utilized to analyze later timeframes, including 2021 through 2024 and 2025 through 2026. Figure 27 below from the capacity management tool shows the current utilized capacity of each shop for the years 2018-2020 compared to the network or individual facility's maximum available capacity for the Gate 3 Engine Testing processes.
Page 147 Network Capacity of PW1100G Test
lSite 1 30K i Site 2 30K Site 3 30K ie430K m ke 30K m $Ie630K - Capacity
Site3 &Site5 -- ~rs- - Online 18QI - --- IOnk*.19421 S42&I fe
-- ~-- nd Duct Set S t 2 S t6St 5n I DuctSat ios n -, S2te49nd Fur 2: Uour 8.A 4nt-o-nt I Reducton. I
9 Hour I 1300%
200%
100%
MIS M92020 Figure 27: Aggregate Utilized Capacity of GTF Test Network through 2020
On the horizontal axis, each year is broken down by month. On the vertical axis, the overall network capacity is shown as the percentage of currently available capacity that is predicted to be required to satisfy the expected shop visit demand. The different colors in the stacked bar represent the anticipated capacity utilized for each test facility in the network. For example, in December 2018, Site 2 (shown by the red bar on the bottom of the stack) is predicted to utilize 90% of its available capacity to satisfy the shop visit demand anticipated for that month. Likewise, Site 3 (in green) will utilize 76%, Site 4 (in purple) will utilize 57%, and Site 5 (in blue) will utilize 74% for a total network utilization of 312% out of total available capacity of 400%. The red line shows the maximum capacity available at the overall network level (assuming maximum capacity available at each site is 100%). With four sites operational, the network has 400% available. There is a capacity increase in January 2019 when Site 6 comes online. The above chart shows that, if work was spread appropriately throughout the network for the PW11 OOG-JM engine model, the overall network would have enough capacity to meet shop visit demand through 2020 with some remaining capacity available to support unexpected removals or surge events. This analysis included both the current approved shops performing work and the facilities preparing to come online in 2018 or 2019.
In addition to analyzing the GTF capacity at a network level to ensure overall capacity is available to meet forecasted repair demand, it was also beneficial to analyze each facility's
Page | 48 capacity utilization at the individual shop level to ensure no single shop is overutilized while others are underutilized. See Figure 28 below. The test facilities at Site 2 and Site 3 were both being almost fully utilized for the entire timeframe between 2018 and 2020. This finding was likely the result of the allocated demand being fulfilled with only one test cell and one duct set. Conversely, at Site 4, overall utilization dropped starting in mid-2018 due to the addition of a second duct set. This finding indicated that Site 4 would have additional available capacity and could be used for surge testing capacity if unexpected repair demand materialized. Site 5 also had a moderate level of capacity not utilized between 2018 and 2020, likely due to the second duct set to be procured. Lastly, Site 6 was shown to have substantial capacity unutilized over this time period; however, this may not be a negative finding. Since Site 6 will be coming online in 2019, the test facility and duct sets may still have periodic troubleshooting required to see all test processes lay flat and test personnel will still be learning test procedures. Therefore, capacity available may not be as high as estimated since efficiency will likely be lower during these first few years in operation.
Included in each facility's individual capacity analysis is a notional measure of uncertainty, shown with error bars in the charts to follow. Uncertainty in the test run data can be translated into uncertainty in the site's capacity prediction. At the completion of this test capacity case study, only one of the below facilities had substantial test run data for the PW1 1OOG-JM engine model and the remaining facilities were either initializing test operations or were completing test cell construction and correlation. However, identifying uncertainty in test time data and facility testing capacity is of benefit in representing relative expertise and consistency with approved test processes among shops over time. Variability in this data is expected to be higher for test facilities in the early stages of engine testing, as test cell personnel are learning a new process and test cell shakedown and troubleshooting will be more prevalent during the first group of test runs. Additionally, variability and uncertainty are expected to decrease over time as each site's test run time for a given workscope converges to the population mean.
Page | 49 PW110 Sfte 2 Tea C"pct 2018- 202 PWI1006 Site 3 Tat Cqft =91 -2020
Sim - -I-
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ills ~ 0 't1111:1 i
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_ 11JIWI 111Gi~ 111134ithaa1lIhifI1fil~i~mil~ sisalNfI1 I lIi 115151I111 11 3l11S i!II11 ll f1iil !5!2i1fill. J i111 PWIIOOG Site 6 TM Cpdy MO - 202
I
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-Ily 1l14411 21115 411111111lisIS11fiuIi I ~Ifsi 110 T1!llh418111hA IM an I I I Figure 28: Utilized Capacity at each Shop through 2020
Using the same process as above, test capacity was determined for 2021-2026, with the results shown in Figure 29 through Figure 32 and discussed below. The overall upward trend of required shop visit demand approaches the network's available capacity beginning in 2022 and periodically surpasses the overall network capacity in 2024. At this point, it is important to consider what level of capacity "margin" or "buffer" is sufficient to ensure operations continue to run smoothly to meet current demand while still allowing for enough capacity to accept unexpected spikes in repairs needed or additional, unplanned demand. Planning to operate at 100% capacity would be unwise since demand forecasts are only best guesses based on data
Page 150 available at the time and demand can change unexpectedly, especially with a newer engine model. If buffer capacity is not available and customers experience higher than expected removals, the PW GTF network would not be able to accommodate these repairs, resulting in longer wait times for customers to receive a serviceable engine and potentially disrupted customer operations. However, too much additional capacity is also a problem - capacity sitting idle is money that could have been spent elsewhere. This is where the 80% capacity limit becomes relevant: enough capacity exists to consistently meet predicted customer demand and additional buffer capacity is available for unexpected demand surging without spending funds on unnecessary excess capacity. See Section 2 above for further discussion.
Sensitivity analysis is also an important consideration in this case study. Building one additional test cell at a given site will not increase capacity since the process will then be constrained by the limited number of duct sets. Ideally, one test cell and one duct set would be added simultaneously to analyze capacity changes in the network. For example, adding one new test cell and one new duct set at Site 2 in Q4 2018 yielded a 50% increase in capacity at Site 2 and a 12-15% increase in capacity network wide. Since these are large, expensive assets with only a few in operation, increasing available resources by just one makes a large impact on site capacity and on network capacity.
With all facilities operating above 80% capacity starting in 2022, unexpected fluctuations in shop visit demand could put the network over capacity prior to 2024, resulting in repair delays and longer TAT to return the engine to the customer. Additionally, these charts only represent the demand for the 30K thrust class (PW1 1 QOG and PW1 400G engine models). The PW1 50OG engine model has just begun to see shop visits, and as additional engine models come online and begin flying, the MRO network will be further taxed. Some of the currently available capacity will likely be shared across these additional engine models as shop visit needs dictate and will place more strain on the already constrained network.
Page 151 Network Capacity of PW1100G Test
in Slte I 30K Site 3 30K Site 4 30K Site 5 30K Site b 30K - -L apaity 600% 1
500%
400%
300%
200%
100%
0% B II-% >1I. 1a4g o
2021 2022 2023 2024 Figure 29: Aggregate Utilized Capacity of GTF Test Network for 2021-2024
Page 152 PW1IAOG SIte 3 Test Capacity 2021-2024 PW1IOOGPW11WGSse Site 2 Test [email protected] Capacity 2021 -2024 2024 F WMG Re stnCa.a 221-2024 ii I i A-VA. I i~Iaidiii IIii ill IIhun 'I'llihtni: I [3%M
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1 I I UII 3)31 3) I 3, 11 PW1I0O Site Tesm Capsct Zi -2024
I IM 5 1 81 , ljllt ~ij8lSS P
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Figure 30: Utilized Capacity at each Shop, 2021-2024
The individual facility charts above show that two MRO sites, while operating at a relatively high capacity utilized, did not surpass the maximum capacity line (100%) during this timeframe. Ideally, this indicates that these facilities could continue to perform without substantial delays, assuming that demand is input as expected and is steady state, with no surges. However, in the period 2021-2024, three of the five network facilities were shown to expect demand exceeding their maximum capacity, with the shop at Site 3 out of capacity for nearly half of the timeframe. This finding is likely due to the increased market share percentage for Site 3 combined with the
Page 1 53 facility's available resources (1 test cell and 1 duct set). These over-capacity situations for Site 3 may be resolved with the procurement of an additional duct set; however, additional network- wide actions will be required to meet the demands of 2025 and 2026.
Network Capacity of PW1100G Test
Site 2 30K Site 3 30K Site 4 30K Site 5 30K Site 6 30K Site 7 30K - Capacity 900%
800%
700%
600%
500%
400% -
300%
200%
100%
Jan T Feb IMarTAprIMay Jn Jul Aug Sep Oct INov Dec Jan Feb Marf Apr TMayT Jun JUl AUg Sep oct Nov Tec 2025 2026 Figure 31: Aggregate Utilized Capacity of GTF Test Network for 2025-2026
Page 1 54 PWI100 Ske 2 Tedt OCaat 2025-2026 PWilOG SRO 3 TMt Capacty 2025 - 2026
It i I I '4 I I Im f~ ii iiii iiii i ii iiii ! iii iii I 1A - r--- r --
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I Figure 32: Utilized Capacity at each Shop, 2025-2026
As the above network-wide and individual facility charts for 2025-2026 show, shop visit demand outpaced available capacity for each month of the period between 2025 and 2026. Additionally, on an individual facility level, each site was shown to exceed capacity for at least 90% of the timeframe, indicating a network-wide lack of capacity to address customer shop visit demand. This larger system-wide issue could be resolved through the construction of additional test cells and corresponding procurement of additional duct sets and support equipment, through the
Page | 55 construction of a new PW-owned test facility, or through a new partnership with an airline customer facility or industry partner.
This same framework and analysis was utilized on the Gate 1 Disassembly and Gate 3 Assembly processes as an additional case study; however, only one facility was modeled for these procedures. Discussion and initial results are presented in Appendix A.
Page | 56 5. Conclusions, Recommendations, and Future Work 5.1. Conclusions
Based on the initial capacity study conducted in early 2017 and this detailed capacity analysis performed for the Gate 3 Engine Test processes, the current GTF MRO network was found to have sufficient capacity available to meet anticipated customer demand through 2021. Here, adequate capacity indicates that forecasted shop visit demand was met and some buffer capacity was available to accommodate emergent, unscheduled customer removals. Even though capacity for predicted demand exists through 2023 for the PW1 1 OOG-JM engine model, many of the GTF facilities were operating at or above 80% utilization in 2022 and 2023 and only very limited surge capability would be available in case of unexpected customer repair requirements. Beginning in 2024, the expected engine repair demand ramp was found to result in the capacity of the network falling short of forecasted repair visit demand. The shortage in 2024 was not crippling and could potentially be resolved through strategic movement of work among facilities and procurement of an additional duct set at the Site 3 facility. These strategic decisions, however, would only provide limited relief as the network was found to widely be operating near 100% utilization and almost no surge capacity would be available. In 2025-2026, the model showed that a larger, network-wide solution will be needed to address systemic lack of capacity. This shortage of capacity results in increased TAT and increased airplane downtime for the customer, which could negatively impact the reputation of PW, the GTF engine model, and the airline customer and could prove costly in future engine competition. Since test cells and duct sets are not off-the-shelf items and need to be built or specially manufactured, planning and funding efforts need to start several years in advance. The planning, contracting, construction, and correlation of a test cell typically requires -2 years before the test cell has completed troubleshooting and is operational. However, gathering approvals for required funding will add more time to this process.
The findings above are in alignment with PW's previous capacity analysis results and provide additional evidence of the need for future capital planning to meet the forecasted capacity demand. PW has developed contingency plans for this potential capacity shortfall and expects to begin implementation as the appropriate lead time approaches.
Several items of interest were noted throughout the analysis that may impact estimates of demand in the timeframe analyzed and the capacity utilized at each facility. First, the demand
Page 157 forecast utilized for the capacity analysis was known to be the best available forecast at the time and was based on past engine sales (indicating the number of engines currently in service and their relative time on-wing) and anticipated future sales (indicating the potential number of future engines in service needing shop visits). However, these demand values are difficult to estimate in the 2024-2026 timeframe since conditions are likely to change when looking far forward. The estimates of demand required and capacity utilized are more accurate in the timeframe of 2018- 2020 and much more closely resemble the current state of the network. As demand estimates are updated in the future, this analysis may also be updated to provide a refreshed view of network capacity.
Second, the use of learning curves, lessons learned, and Achieving Competitive Excellence (ACE) initiatives were found to play a large role in continuous improvement and TAT reduction in the GTF MRO shop environment. Learning curves were a useful tool for tracking actual efficiency gains versus expected efficiency gains from completion of personnel training, process learning and refinement, and increase in proficiency of process task execution. As the team progresses down the learning curve and processes and work requirements become more familiar, TAT should decrease, variability in TAT should decrease, and overall facility and network capacity should increase. These improvements are the result of employees removing waste from the process, teammates becoming faster and more efficient in performing work steps as tasks evolve, and more effectively laying out facilities to improve workflow from one work cell to the next. As the GTF MRO network continues to gain experience with this new engine model, the team will keep moving further down the learning curve toward the overall TAT goal of 90 days.
5.2. Recommendations
Operations: As shown in Section 4.4.2, based on the assumptions detailed and the demand forecast provided, the current engine testing network was predicted to exceed the 80% capacity threshold in 2022 and exceed the 100% capacity maximum in 2024 for the 30K thrust class. The below PRDCs in Figures 33 and 34 identify this trend and provide an estimate of funding and construction, procurement, or partnership milestones required to bring additional capacity online prior to this timeframe. Each of the two major options has benefits and disadvantages. First, the construction of new test cells and procurement of new duct sets at existing PW sites likely requires a higher level of funding, more time to create detailed construction plans and schedule
Page | 58 work with building contractors, and additional time and funding required to hire and train the new workforce at these sites. However, these test cells would be PW-owned assets and would not be subject to asset-sharing often seen with partner companies. Alternatively, contracting with an industry partner to utilize existing facilities would also bring benefits, such as lower capital investment required upfront and development of a stronger customer relationship. However, PW would lose some control over scheduling and inductions since the asset would be owned by another organization and other customer engine models would also be utilizing the same capacity, reducing available capacity for GTF engine testing.
Network Capacity of PW1100G Test 030% - __-- -~Begincell I - - - construction, I
70A prouremnA I f~unds IIcapacity required I eonn f Begin capactyt 60D% -1 study to locate ------
fuurcels Down-select sies , I IHirin and for new cel(s) I J trairin if
10%3%
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21208 00 2021 2022. 2023 2024 2025 | 2026
inslte 2 30K Site 3 30K S8e5 4 30K inShe 5 30K 6 l Site 6 30K -Capacity Figure 33: PRDC for New Test Cell(s) and Duct Set(s) The PRDC above shows the estimated milestones to be met to have additional capacity operational by the first quarter of 2024 by constructing new test cells or expanding test facilities at existing sites and by procuring additional duct set equipment to support the increased test requirements. Allowing for hiring and training, test cell construction and correlation, funding requests, and test cell location studies and down-select decisions, the process should begin in the mid-2020 timeframe.
Page 159 Network Capacity of PW1100G Test
802%.r -m Begin contracting I
700% - - -- - partner/customer organiationAdditional capacity required 6()n% I_ to be online I Begin capacity study I II Correlation, hiring, I and discussions with I I and training, if 500% 7------A potential partners L -- - required
400% -
302%
0%
r- -,C 2018 2019 2020 2021 2022 2023 2024 2025 2026
M Site 2 30K M $ite 3 30K Site 4 30K MlSite 5 30K Site 6 30K -C apacity Figure 34: PRDC for New Partnership(s)
For the partnership option, discussions would also likely need to begin in the 2020 timeframe, either with prospective new partners or to expand capacity at existing partners. One potential customer partner to consider for the PW1 1 QOG engine model is Delta Airlines, who recently announced their intent to purchase 200 Airbus A320neo aircraft equipped with PW's GTF engine model 37. This announcement provides PW with an opportunity to partner with Delta to maintain and service these new GTF engines after delivery and to strengthen their relationship with this airline customer, potentially leading to additional engine procurements in the future. Other options for expanding capacity include contracting for additional test capability at existing GTF partners.
Other opportunities for improvement include identifying successful aspects of operations at one facility to drive similar improvements at other DAT shops and centralizing operations data to use one authorized source to reduce the potential for differing data sets. Active discussion and transfer of shop best practices from one facility in the network to others would benefit customers by reducing the shop's TAT and overall network TAT, encourage additional inter-shop relationship-building and communication of best practices and lessons learned, and standardize processes across facilities. By identifying one common configuration (for example, the flow line
3 Russell, Edward, "Delta Picks A321neo for Narrowbody Replacement"
Page | 60 concept) which has performed consistently and met or exceeded expectations, applicable elements of that setup can be implemented in other facilities, helping to improve overall shop operations, reduce rework, and decrease TAT.
Ensuring all teams are utilizing the same base data set, whether it is program demand forecasts or actuals for shop visit deliveries, will provide one common starting point for analysis and will reduce confusion concerning which data set is up-to-date, most accurate, or officially authorized. Likewise, follow-on communication would be necessary to ensure all teams are cognizant of the authorized data to be used and the group responsible for maintaining and updating it.
Management: From the operations and management viewpoint, the GTF Aftermarket Operations organization was found to be well-run with involved, vision-oriented leadership and skilled, empowered team members. Teamwork and cooperation were prevalent in ensuring success in daily tasks and in long-term process improvement initiatives. Two areas stood out as opportunities to further improve GTF work processes: communication of lessons learned and Value Stream Mapping (VSM) of office-based support organizations.
While GTF program lessons learned seem to have mostly been communicated during VSM efforts and during semi-annual or quarterly All Shops meetings, an opportunity exists to expand this knowledge sharing to a more frequent basis. A great weekly VSM update meeting was held for several months to track implementation of VSM initiatives and their impact on shop TAT. This VSM initiative tracking information would have also been useful to review with the other GTF MRO facilities. Regular communication on a weekly basis or as issues with multi-facility impact arise would improve inter-shop relationships and would speed the implementation of both technical and operations-related solutions. For example, one GTF DAT facility discovered difficulty with a specific piece of tooling and implemented several modifications to ensure proper functionality. This information would have been useful to immediately share with the remaining facilities to prevent a similar struggle with the same tooling. With international shops involved, this change would likely require regular involvement of PW's International Trade Compliance group to ensure compliance with all applicable export-related requirements. Even though additional controls may be required, increased knowledge sharing across all GTF MRO
Page | 61 facilities, especially of EagleNet cases and approvals, would yield improvements in TAT and would further strengthen relationships for long-term GTF success.
A VSM exercise can be an important tool for identifying waste in a given process and streamlining operations on the shop floor. However, the VSM process can also be applied to the office environment, and areas for improvement through VSM exercises were identified in the GTF aftermarket organization. It was discovered that multiple groups in the organization were performing essentially the same function and job tasks and these groups had been duplicating work efforts. For example, several groups were performing engine scheduling tasks (tasks related to scheduling an engine for repair) without communication among groups. Additionally, several teams were found to be performing independent capacity analyses, likely with different inputs, methodologies, and results. A VSM exercise performed to analyze and simplify processes for GTF support functions would provide the organization with more clearly defined job roles and responsibilities, reduced duplication of work and unnecessary meetings, clear reporting structures, and key contacts for interfaces with related teams.
5.3. Future Work
The framework developed for this thesis and implemented in the case study presented above lays a strong foundation for future capacity analysis projects. With respect to PW's GTF engine family capacity analysis, the case study undertaken focused on Gate 3 Engine Testing. However, other areas in the process could also benefit from this analysis. In partnership with the PW ECMPS group, the Gate 3 Test model should be updated as new facilities come online, new support equipment is procured, and as process times decrease. Likewise, the initial model for Gate 1 Disassembly and Gate 3 Assembly (shown in Appendix A for Site 2) requires additional work to apply the framework to the remaining DAT sites. Once all sites have been analyzed, a single network-wide analysis should be completed using data from all facilities to give a clear image of the capacity of the network.
Another area of possible implementation of this framework is on the Gate 2 Repair processes. These processes present a considerable challenge since the workscope for these piece-parts may be unknown until after incoming inspection is complete. Additionally, depending on the level of wear identified and repair required, the piece-part may be routed to an internal back- shop or to an external supplier, further complicating the analysis. However, assumptions can be made based on historical findings and workscopes, average cycle times can be used, and
Page | 62 increased flexibility can be built into the model to allow for a high-level view of the capacity of the Gate 2 Repair network. The completion of the Gate 2 Repair model will also allow for a combined model representing the capacity of the entire GTF aftermarket operations network for repair and overhaul of this engine family.
As the capacity model framework continues to transform and further develop, verification and validation of process times would be quite useful. An Industrial Engineering group could perform time studies on the shop floor across several sites, over several time periods, and following different mechanics, inspectors, and test operators to obtain a more complete distribution of cycle times for any given process. A test process simulation using test data available and the capacity model provided in this thesis could also serve well to verify that the model performs as expected and accurately represents the process being studied. This increased robustness as additional DAT data becomes available will serve to increase accuracy of the model and provide PW leadership with a clearer image of when additional resources will be needed and where they should be located for the most impact.
Page | 63 6. Appendix A - Initial Gate 1 Disassembly and Gate 3 Assembly Framework 6.1. Proposed Capacity Model The process for analyzing capacity for the Disassembly and Assembly procedures was similar to that of analyzing capacity for the Engine Testing procedures. In-shop investigations and personnel interviews were critical in gathering cycle time data, process flow information, and resource availability and utilization data. In this phase of the case study, one facility was visited and analyzed.
First, after viewing the shop floor and process layout, a process map was created showing the flow of engine parts through the Gate 1 Disassembly and Gate 3 Assembly repair processes. Two process maps were created; one for the light workscope (#3 Bearing/Combustor) and one for the heavy workscope (MTS). One area of insight taken from these maps is the sequential nature of the shop flow. Overall cycle time could be reduced by working some tasks in parallel instead. This could be accomplished by incorporating a method for moving parts immediately or in smaller batches from the disassembly area to the inspection area instead of waiting for all parts to be disassembled and moved at one time. By creating smaller batches, the inspection group can work a steady stream of parts over time instead of being overwhelmed by one large group of parts needing inspection.
Next, each process step was documented and assigned to the appropriate work cell. Facility process engineers and site operations managers assisted in identifying the resources (here, number of mechanics) required for each task and the typical time required to complete the task. These were converted into man hours and cycle time hours using the below equations.
Man hourstask = (# of mechanics) * shift length (-) * (# days to complete) (hr Cycle time hourstask = shift length (-) * (# days to complete)
The cycle times required for the tasks performed in each cell were summed and charted to aid in the identification of the tasks with the longest cycle time and requiring the most labor resources.
Page | 64 The collected manpower data confirmed topics of discussion during personnel interviews with shop floor employees and operations managers - the bottleneck tasks, those requiring the most process time and manpower, are inspection during Gate 1 and engine reassembly in the engine bay during Gate 3. This cycle time data helps to understand where most resources are dedicated and, if cross-training allows, where resources can be transferred from to assist in level-loading work across tasks. If cross-training programs are in place, mechanics from lower- utilization areas, such as the core cell, can be moved to higher-utilization areas, such as disassembly in the engine bay, as demand materializes.
Capacity available, based on manpower, can be evaluated at either of two levels: a higher-level, less detailed viewpoint or a lower-level, more detailed viewpoint. This involves looking at the process at the major task level or analyzing capacity for each subtask. The below discussion applies to both scenarios - the difference is in leaving the analysis at the top level (for example, "engine bay") or analyzing each major process at a lower level (for example, "remove the fan case"). Additionally, if the facility added a second shift or increased the length of the first shift, updates could easily be made. Likewise, as additional resources are added to the DAT facility and as first pass yield and efficiency increase, the tool can be updated to reflect the current environment. These inputs can also be altered to be used in scenario planning to investigate the impact of adding another cell or shift before committing the needed finances or resources.
Available Process Hours per Quarter
hr ( r p er S h if t ( ( (a iis jts T im e weeks * (Current Resources + Additional Resources) * First Pass Yield * 13 )
(days\ * 5 dwee * Ef ficiency (week))/
Page 1 65 Available Process Hours per Month
per Shift -h (a Z Time iweeks~ * (Current Resources + Additional Resources) * First Pass Yield * 4 (month)
* 5 week)* Efficiency
Using the available process time and the provided cycle time for each process, the facility's capacity by quarter and by month were determined. Capacity relative to the identified shop bottleneck(s) can also be determined for additional analysis.
Available Process Hours per Quarter Capacity by Quarter = CceTm Cycle T ime
Available Process Hours per Month Capacity by Month = CceTm Cycle T ime
The above framework for analyzing capacity for Gates 1 and 3 can be replicated for operations at different facilities, different demand planning scenarios, and for different workscopes. Several improvements can also be made to yield a more robust capacity analysis tool. For Gates 1 and 3, the overall shop capacity can be found (similar to the results in the Engine Test process) by differentiating between the multiple workscopes and process times encountered by the facility. Using a workscope mix percentage and workscope-unique cycle times, a more accurate Disassembly/Assembly capacity would result. Additionally, another tool to create benefit for the facility in managing capacity and resources was a Resource Matrix, shown in Figure 35.
1xIltpihg* *$tUKS2 -- I yE
Page 66 This matrix could be utilized to track manpower staffing levels for both mechanics and inspectors, training program progress for new hire employees, cross-training progress across tasks, and availability of shared resources. This matrix can also be useful in tracking tooling or equipment to ensure on-time re-certification or re-calibration and in establishing and maintaining engine bays for use.
6.2. Preliminary Results for Single Facility The second phase of the case study analysis focused on characterizing both the current and planned capacity of the GTF MRO network to perform the activities contained in Gate 1 Disassembly & Inspection and in Gate 3 Assembly. The tasks required in each gate depended on the workscope for each specific engine - lighter workscopes did not disassemble all modules of an engine and may only disassemble selected modules to either assembly-level or to piece- part-level. Heavier workscopes required disassembly of major modules and typically required disassembly of these modules to a lower level.
Gate 1 Disassembly consisted generally of disassembly of the engine into major modules, disassembly of selected modules to the assembly level or piece-part level, inspection, cleaning (if required), and routing to the serviceable storage area or to internal or external repair. Gate 3 Assembly consisted of reassembly of all serviceable parts to the module level, stacking and balancing of major rotating groups, assembly of major modules into the complete engine, and installation of any removed external pieces such as cooling air ducts, fuel nozzles, and oil lines.
One difficulty often experienced during Gate 1, particularly with engines planned for light workscopes, is the potential for workscope creep. Creep occurs when an engine returns to the shop for certain work to be performed but, after the initial borescope inspection or disassembly and inspection steps, additional work becomes required due to damage or wear that was not previously known. This requirement creep situation is essential to consider during capacity planning and sizing of new facilities to ensure adequate floor space relative to estimated future demand.
6.2.1. Available Facilities
With the relatively recent entry into service of the GTF (both the PW1 1 OG installed on the Airbus A320neo family and the PW1500 installed on the Bombardier CSeries), many MRO facilities are still developing their workspaces, creating flow lines, hiring and training mechanics
Page 167 and inspectors, and constructing facility expansions. The current network of shops performing repair work on the GTF consists of the below facilities listed in Table 7.
Table 7: GTF MRO Repair Facilities Available or In-Work Facility Models Available Comments Date Repair Site 1 PW11 OOG Operational 9 Expansion in work PW1 500 Operational * Due to complete mid-2018 Repair Site 2 PW1 1 QOG Operational e Uses flow line concept Repair Site 3 PW1 1 QOG Operational e Expansion in work e Due to complete late-2018 Repair Site 4 PW1 1 OG Operational PW1500 2018 Repair Site 5 PW11OOG 2019
Additionally, several other facilities are under consideration for capacity expansion if required. These agreements and expansions, if pursued and approved, are expected to be in place by 2021 to meet the expected ramp of shop visits required. One additional source for GTF work is also desired to meet this coming surge of work, and several PW facilities are being analyzed for the best fit in the MRO network.
6.2.2. Available Tooling per Process
Based on each shop's currently approved capabilities and expected repair workscope distribution, different support equipment and tooling is needed. For example, a facility performing workscopes where the LPC does not require tear-down, would most likely have not yet procured the tooling needed to disassemble, repair, and store components of the LPC. As each facility expands its capabilities list and as workscopes gravitate toward scheduled, heavy maintenance shop visits, each MRO shop will source the required support equipment and tooling for work on all engine modules. This tooling includes both standard and unique tools required to perform disassembly, repair, and assembly processes, such as balancing machines, inspection booths, vertical assembly stands, and tooling for the unique FDGS. Each facility will also procure or manufacture GTF-specific support equipment for storage and movement of assemblies or modules.
Page 168 6.2.3. Manpower / Labor
In addition to having adequate floor space and tooling for the engine repair process, the MRO network requires an efficient, trained workforce to perform the required repair tasks. Several differences exist between the PW-owned facilities and the GTF partner facilities, including available work schedules, expectations for overtime work, unionization of the workforce, and days off each year for local or national holidays. Table 8 below summarizes the current work schedules in operation at each facility.
Table 8: Available Work Schedules per Site Facility Work Schedule Comments Repair Site 1 Standard: M-TH (10 * 2 standard and 1 alternate hours/day) * Adding 2nd alternate in Alternate: F-SU (12 2018 hours/day) Repair Site 2 2 shifts and -5.5 days/wk Repair Site 3 1 shift and 5 days/wk Ramp-up ongoing Repair Site 4 1 shift and 5 days/wk Ramp-up ongoing Repair Site 5 TBD Start 2019
Two areas of interest arose during the in-shop interviews. First, there was an initiative at some facilities to cross-train mechanics to be proficient with both the disassembly and the assembly processes. By having personnel who can perform both sets of tasks, the facility can level-load manpower on a more fine-grained basis as demand needs materialize day-to-day or week-to- week. Mechanics can be moved from one area of the shop to another or from one process to another due to a number of factors, including coworker absenteeism, material or process delays in one shop area, and re-prioritization of specific engines, workscopes, or customers. This cross-training, or pooling of labor skills, provides an added level of flexibility and allows the facility to be more responsive to rapid changes in demand or to changing requirements in the shop floor environment. Additionally, level-loading work across selected facility processes enables a smoother flow of parts through the shop and less stress on employees.
Second, at the GTF partner sites, not all work being performed in the shop is PW or GTF program work. There are other engine manufacturers and other customers who send work to these partner sites to be accomplished. This finding was incorporated into the capacity analysis by estimating (when data was not available) the percentage of PW or GTF work being performed compared to the total. Likewise, PW facilities do not work solely on the GTF engine family. For these PW-owned facilities, data was available and was utilized in determining the
Page I69 total capacity of the facility and the capacity available for GTF work. The next section discusses the capacity findings for Site 2.
6.2.4. Initial Assessment for Site 2 for Gates I and 3
For the heavier MTS workscope, the capacity analysis identified the inspection process in Gate 1 Disassembly as the process bottleneck. See Figure 36 through Figure 38 below. This finding is likely due to the limited number of resources available (two fully-trained inspectors and two inspectors in training) and the sharing of these inspection resources among programs. The fully- trained inspectors are also required for the induction processes, further reducing their availability. To reduce strain on the inspection section of the process, additional inspectors can be hired, trained, and added to the workforce or the currently approved inspectors can be dedicated to the GTF program with additional hiring likely required to support other legacy programs.
W Wdft a" Wft NdSIIR *Of AWnymUk rror~ma rMe liW 7b". Ceerem det W EPYK fo" O - v~b AvaIMabe AMMA NaSW~s &OUMa % MlWn~lr MlWn/lr rG.- Nm ------pao -rm e ud per Month NaOe hiduction 8 0 0 1 100% 75% 390 120 -a Ba 8 0 0 3 100% 75% 1170 360 -Core C. 8 0 0 1 100% 75% 390 120 ModuLe Cd 8 0 0 1 100% 75% 390 120 HPC Cel 8 0 0 1 100% 75% 390 120 a C k f 8 0 0 1 100% 75% 390 120 hei 8 0 0 1 100% 75% 390 120 8 0 0 1 100% 75% 390 120 8 0 0 1 100% 75% 390 120 a 0 0 1 100% 75% U 120 8 0 0 1 100% 75% 390 120 _ a_ 0 0 1 jQO 76% 390 120 _ _ _ _ _ HPC CeI a 0 0 1 100% 75% 390 120 Module CeN 8 0 0 1 100% 75% 390 120 core Cel 8 0 0 1 100% 75% 390 120 EcO l 8 0 0 3 100% 75% 1170 360 Test CeI 8 0 0 1 100% 75% 390 120 Sh-- 8 0 0 1 1 100% 75% 390 120 Figure 36: Site 2 Gate I and Gate 3 Available Hours
Page I 70 Available Available Capacity By Capacity By Target Target Process Process Quarter Month Quarterly Monthly Min/Hours MiniHours Cycle Capacity By Capacity by Defined by Defined by Requirements Requirements Gate Oprtlon Process per Quarter per Month Time Quarter Month Bottleneck Bottleneck Basic Process Basic Process _nduction 390 120 20 19 6 5 1 Enain Ba 1170 360 60 19 _ 6 - Core Cell 390 120 20 1 _ 6 Mode Cel 390 120 40 _ 3 OW HPC Cel 390 120 20 19 6 i5 Ceai 390 120 8 48 16 390 120 72 5 1 0 390 120 0 -4 0 390 120 0_ C- 0 390 120 0 0 390 120 a 0 390 1 0 HPC Cel 390 120 52 7 2 Module Cel 390 120 52 2 Core Cel 390 120 20 19 6 C EngineBay 1170 360 80 14 4 Test Cel 390 120 16 24 7 Se1irig_390 120 24 18 __ Figure 37: Site 2 Capacity and Bottlenecks
90
'0 __ __ _
10
0~ d
Nora Egi
oal 0M2 m
Figure 38: Loading by Process - Heavy Workscope
The capacity analysis for the MTS workscope indicated that substantial loading was occurring in Gate 3 in the HPC Cell build, Module Cell build, and Engine Bay final assembly. These results made intuitive sense as it likely required more manpower to pull parts, check for proper documentation, and re-assemble, within limits, each module than the time required to disassemble the engine and route the parts to cleaning and inspection. At Site 2, these are also shared resources - the personnel disassembling the engine are the same ones reassembling it. The personnel disassembling the HPC in the HPC Cell are the same ones performing reassembly. Additionally, Site 2 indicated that for each work bay area, there was one fully trained mechanic and several mechanics in training. The high number of trainees is likely driving up process cycle times since the fully-trained mechanic is also teaching, not dedicating 100% of
Page 171 his effort to completing the work process. Figure 39 below shows the findings for the lighter workscope.
so
50 --.----
2050 ------
0 -
GF rLresW G9 s Figure 39: Loading by Process - Light Workscope
Analysis of the lighter workscope repair processes yielded similar results as the analysis of the heavier workscope. Inspection and Engine Bay work again were found to be the most time- intensive operations in Gate 1 (Disassembly). In Gate 3 (Assembly), Engine Bay was the most heavily loaded process. These results also made intuitive sense for the same reasons as discussed above. For the light workscope in particular, a large portion of the work involved disassembling the engine to the appropriate level to gain access to the appropriate area and reassembling the engine once the repair was complete. Inspection would also take considerable resources since all exposed areas of the engine and each module must be inspected to ensure maintained serviceability before being moved to the storage area to await reassembly.
Page 172 7. References
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Page | 73 Pratt & Whitney. MTU Capacity Analysis, REV A. PPT.
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7.2. Glossary of Acronyms Acronym Definition Description ACE Achieving Competitive United Technologies Corporation's lean Excellence manufacturing program AOG Aircraft on Ground An aircraft is experiencing serious technical issues preventing the aircraft from continuing operations BPR Bypass Ratio Ratio of mass of inlet air which bypasses the engine core to the mass of inlet air entering the core CEC Columbus Engine Center Pratt & Whitney overhaul facility in Columbus, GA CSN Cycles Since New Total accumulated engine cycles in operation since production CSO Cycles Since Overhaul Accumulated engine cycles in operation since the engine's previous overhaul shop visit DAT Disassembly, Assembly, and Designation for a repair center which performs Test engine disassembly, reassembly, and testing EASA European Aviation Safety European Regulatory body responsible for Agency managing civil aviation EBU Engine Build-Up Final installation of external hardware and accessories following test prior to delivery to the customer ECMPS Enterprise Capacity and PW group responsible for OEM and Aftermarket Materials Planning Strategy capacity analysis EEC Electronic Engine Control Control box on the engine used to communicate with the test operator and make changes to engine parameters (such as thrust settings) during engine test EIS Entry into Service The date of a new aircraft or engine model's first commercial flight with an operator ESA Eagle Services Asia Pratt & Whitney overhaul facility in Singapore ESN Engine Serial Number Unique engine identifier, assigned at time of production FAA Federal Aviation Administration United States Regulatory body responsible for managing civil aviation, including repairs to aircraft engines
Page 1 75 FDGS Fan Drive Gear System Integrated gear system separating the fan from the low speed rotor, allowing each to turn at its optimum speed FOD Foreign Object Debris Any object that does not belong to the engine/system and could cause damage upon ingestion GE General Electric One of three main competitors in the aircraft engine design, manufacture, and support market GTF Geared Turbofan@ Next generation engine produced by Pratt & Whitney providing substantial improvements in engine noise, emissions, maintenance costs, and fuel efficiency HPC High Pressure Compressor Module located between the LPC and Combustor; responsible for compression of the air before mixing with fuel for combustion; driven by the HPT HPT High Pressure Turbine Module located between the Combustor and LPT; responsible for extracting energy from the air fuel mixture; drives the HPC IAE International Aero Engines Global partnership of PW, JAEC, and MTU on the V2500 engine program ICA Instructions for Continued FAA-driven requirements to ensure airworthiness Airworthiness is maintained throughout the operational life of the product IHI Ishikawajima-Harima Heavy GTF partner overhaul facility located in Mizuho, Industries Japan JAEC Japanese Aero Engine Partner in IAE on the V2500 program Corporation LHT Lufthansa Technik GTF partner overhaul facility located in Hamburg, Germany LLP Life Limited Part A part whose life in the engine is controlled and limited to a certain number of engine cycles by type design, ICAs, or engine manufacturer; part must be removed before reaching the cycle limit LPC Low Pressure Compressor Module located between the fan and HPC; provides initial compression of the inlet air; driven by the LPT LPT Low Pressure Turbine Module located between the HPT and the engine exhaust section; provides additional extraction of energy from hot gases and drives the LPC MRJ Mitsubishi Regional Jet The first aircraft announced offering the GTF as the engine of choice
Page 1 76 MRO Maintenance, Repair, and Facility which provides maintenance services for Overhaul airlines after an engine is removed from the aircraft MTS Motor to Start Heavy workscope during shop visit OEM Original Equipment Organization responsible for the initial production Manufacturer of a product or system PRDC Production Readiness Decision Timeline chart identifying timing of activities such Chart as procurements, production increases, or manpower additions required to meet increasing demand PW Pratt & Whitney Division of United Technologies Corporation which designs, produces, and services aircraft engines and auxiliary power units for both military and commercial applications RQL Rich Quick Quench Lean New technology employed in the TALON X combustor to reduce engine emissions RR Rolls-Royce One of three main competitors in the aircraft engine design, manufacture, and support market TAT Turn-Around Time Number of calendar days from engine induction to engine delivery back to the customer TSN Time Since New Total accumulated engine hours in operation since production TSO Time Since Overhaul Accumulated engine hours in operation since the engine's previous overhaul shop visit UTC United Technologies Pratt & Whitney's parent organization - a Corporation conglomeration of organizations also including UTC Aerospace Systems, Otis, and UTC Climate, Controls & Security
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