LES  RÉACTEURS  F 100  ET  F 119


Walter Bylciw

Vice-President F 119 Program

Pratt & Whitney Government Engines


            Good afternoon, ladies and gentlemen. It’s a great honor for me to participate in this prestigious event. My name is Walt Bylciw, and I am Vice President of F119 Programs at Pratt & Whitney - the program manager for the F119. There is a definition of the aerospace industry program manager’s job that I believe is appropriate for my remarks today. That definition says that a program manager is like the conductor of an orchestra in which each musician is a member of a different union. I will discuss two of the strategies we have used to work toward bringing all of the musicians into the same union - not to make the program manager’s job easier, it does not accomplish that, - but to make the product better, the music sweeter.


            My mission today is to tell you about Pratt & Whitney’s military engine programs. As our name - Government Engines & Space Propulsion - implies, we are responsible for military gas turbine engines and space propulsion systems. In fact, our facility on the edge of the Florida Everglades is the only place in the world that I am aware of where jet engines and rocket engines are developed and tested side by side. As you may be aware, our alternate high pressure oxidizer turbopump will make its debut, installed in one of the shuttle’s main engines, on the next shuttle mission, which should happen soon. Because this is an aircraft engine symposium, I will focus on military jet engines, which encompass fighter and airlift power plants. Our F117, the engine for the C-17 Globemaster III, is a military version of our commercial PW2000 series. Bob Leduc will cover the PW2000 family later, so I’ll stick to the fighter engines and, to be more specific, the F100 and F119.


            Let me start by telling you how Pratt & Whitney is structured and located. Pratt & Whitney is a division of United Technologies Corporation of Hartford, Connecticut. Pratt & Whitney Canada, headquartered in Longueuil, Quebec, is responsible for design, manufacture and support of small jet and turboprop engines for commuter airliners and private and business aircraft. The Operations unit, with headquarters in East Hartford, manufactures large commercial and military engines and provides overhaul and repair services. Large Commercial Engines and Government Engines & Space Propulsion are responsible for every aspect of their respective engine programs except production.


            This symposium commemorates the one hundredth anniversary of the French aircraft engine industry and Snecma’s 50th. By coincidence, this year also marks Pratt & Whitney’s 70th anniversary. During that time, Pratt & Whitney established a long heritage of military jet engine development and production. The first all-Pratt & Whitney designed turbojet engine, the J57, revolutionized the industry. It was the first twin-spool, axial-flow turbojet and the first to provide 10,000 pounds of thrust. Following its debut in the giant eight-engine B-52, almost every United States airframe
company designed a plane around the J57. It powered the Air Force F-100, F-101 and F 102 fighters ; the Navy F4D, A3D and F8U fighters, the KC-135 tanker ; the original U-2 reconnaissance plane ; the 707 and DC-8 airliners ; and even the Snark intercontinental guided missile. The succession of turbojet and turbofan engines that followed led to the F100 and now to the F119, the principal subjects of my remarks here today. The F100 engine has been in production for twenty years, and the F119 is at the mid point in its development program. You can see on this chart that since the 1950s and 1960s the number of new aircraft and engine introductions has decreased and the time between new introductions has increased. This illustrates the realities of our market today and the challenges we have in managing our work force.


            Now, let’s turn our attention to our activities with the F100 family of fighter engines and its two newest members to enter service, the PW-220 and PW-229. This program is an example of evolutionary development of a mature product to satisfy the needs of our US Air Force customer.


            Powering two-thirds of the world’s F-16s and all F-15s, the F100 family has piled up impressive statistics, flying out of 93 bases worldwide in the service of 17 different nations.


            Following an intense competition in the early 1970s, the F100-PW-100, with an eight-to-one thrust-to-weight ratio, was selected to power the twin-engine F-15. It entered service in 1974 and soon established eight world time-to-climb records. A few years later, the F-16 lightweight fighter entered service, powered by a single F100-PW-200. After more than 10 years operational experience with the 100 and 200 models, Pratt & Whitney, in cooperation with the US Air Force, undertook development of an increased durability version, called the PW-220. That was followed by the PW-229 Increased Performance Engine, which built on the proven durability improvements of the dash 220 while producing increased thrust. Continuing this low risk evolutionary process, the company now has available for development an increased thrust version of the PW-229.


            Our engineers had been accumulating technology since the first F100 went into service. We introduced the latest single crystal technology and advanced cooling concepts into the dash 220 design to increase component life and enhance safety and reliability. We added a digital electronic engine control, which provides precise control over fuel flow for smooth throttle transients and lower fuel consumption. In conjunction with the electronic engine control, we designed an engine diagnostic unit to isolate faults and simplify maintenance. The engineers did their job right, because the PW-220 immediately established new standards for safety, reliability and maintainability, including a major reduction in maintenance work hours per engine flight hour compared to earlier F100s.


            Our next challenge was to provide more thrust without sacrificing the reliability and durability gains made by the PW-220. Greater airflow and compression ratio and a small increase in turbine temperature enable the PW-229 to provide 29,100 pounds of takeoff thrust, 24 percent more than earlier F100s at sea level static and up to 35 percent more thrust in certain areas of the flight envelope. This engine also offers unrestricted throttle movement throughout the flight envelope. As an evolutionary design, the dash 229 incorporates and extends the technologies that give the dash 220 its exceptional safety, reliability and durability. In designing the dash 229, we challenged ourselves to provide the increased thrust in the same size frame. We were successful, and the PW-229 can replace the engine in any F-15 or F-16. The dash 229 entered service in 1990 and is currently meeting or exceeding our expectations.


            For many years now, we have been working on thrust vectoring nozzles to enhance takeoff and landing and inflight maneuvering. You’re looking at our pitch yaw vectoring nozzle, which vectors in any direction around the circle. It draws on earlier Pratt & Whitney nozzle programs, the F-15 Short Takeoff and Landing/Maneuver Technology Demonstrator and the F119 nozzle for the F-22 fighter, about which I will talk next. Both are pitch vectoring nozzles, and each underwent highly successful flight demonstration programs. One of these nozzles, mounted on an engine mock-up and operated by normal cockpit controls, will demonstrate vectoring at our exhibit at the airshow next week. The next step will be a flight test program, scheduled to begin this summer.


            Next we turn to my favorite subject ... the F119 engine and the F-22 Advanced Tactical Fighter. This combination was chosen following an extensive flight demonstration program as the US Air Force’s next generation air superiority fighter. Our introductory slide shows the thrust vectoring nozzle I just mentioned.


            The F119 development process has been an evolutionary one ; an evolution of the requirements and the technologies to meet those requirements. Just six years after the F-15 entered service, plans for its replacement got underway with studies to establish performance requirements and optimum cycle and to examine needed technology. Early verification of key technologies during the demonstrator phase, followed by prototype engine testing and flight demonstration and validation, have assured a relatively mature engine design as we entered the engineering and manufacturing development - EMD - phase. Including manufacturing in the name of the program was an intentional strategy to emphasize the importance of early manufacturing involvement in the development process.


            Pratt & Whitney was selected to develop the F119 engine for the F-22 in April 1991. The very successful critical design review of the engine was completed in mid 1992 and, by the end of 1992, we had our first engine at test. Our first production design nozzle started testing in mid 1993. To continue the low risk approach started with the prototype, the program plan has been carefully laid out in great detail. All of the early test engines are very highly instrumented to verify the design in the initial diagnostic testing. Where test data does not match design goals or predictions, aggressive analysis occurs to determine the root cause for the difference between design expectations and test data. Only after the root cause is identified, do we initiate corrective actions. This approach has served very well in keeping program risk low. Manufacturing has been involved earlier in this program than any other Pratt & Whitney military engine program. Our current test engines are built with over 80 percent of the parts from the source that will produce them in production. All of the 27 flight test engines will be produced by the production source and assembled by the production assembly line. We will deliver the first two flight test engines to Lockheed in late 1996 to support a first flight of the F-22 aircraft in the first half of 1997.


            The US Air Force identified the features necessary to maintain air superiority in the 21st century. The F-22 was designed to provide those features, which placed specific demands on the engine design. Supersonic persistence and maneuverability required higher turbine temperature capability. Extended range is enhanced by a fuel efficient, light weight engine. Supportability and affordability objectives were met with a producible and maintainable design with far fewer parts than current engines. We developed special technologies to help reduce observables.


            In fact, the F119 has 40 percent fewer parts than current engines. This is made possible, in part, by advanced technology which permits fewer stages in the compressor and turbines. In the 35,000 pound thrust class, the F119 employs a fourth generation full authority digital electronic control. It is designed for fuel efficiency and ease of maintenance.


            Supersonic persistence, also called super cruise, is the ability to exceed the speed of sound for extended periods without the use of augmentation or afterburning. As you can see by the chart on the screen, the F119 produces roughly double the non-augmented thrust compared to the F100-PW-229, making supercruise possible. With augmentation, the F119 enhances combat capability by providing approximately 50 percent greater thrust.


            We designed the engine to provide a balance between what it could do in flight and what it would take to keep it flying. As the headline on the screen says, we had both the pilots and the mechanics in mind.


            Our design strategy focused on two key elements in our effort to meet all design goals. First, we commited ourselves to the integrated product development concept. Secondly, we utilized the Air Force’s « Blue Two » program to gain valuable lessons learned, which were incorporated into the engine design. These are the two strategies I mentioned at the beginning to get all the musicians into the same union.


            In the past, the various functional organizations or specialities shown in the box at the top left have operated very independently. Each would do its job and do it in its turn or order. Engineering would always start the work and do the biggest part of the work. Then the others would get involved to try to decide how to build it, support it, and maybe sell it at a price to cover its cost. That is obviously a bit of an exaggeration - but not too much exaggeration in my experience. This program is different in both the unprecedented level of team work between the US Air Force, Lockheed Team, and Pratt & Whitney, as well as, the extensive use of IPD. Integrated Product Development is a process involving multi-discipline teams at all levels from the beginning. These teams ensure that design engineers have the benefit of points of view from all functions involved in manufacturing and supporting the engine. You will note the US Air Force represented at each level with the contractor - which is the Pratt & Whitney, Lockheed and Boeing team. Sub-contractors are now an integral part of our development team. There is one lead team, or integrated product management team, which accomplishes the normal executive functions, defining what must be done, providing the resources to do it, and coaching and helping all along the way. Component teams are responsible for major engine sections, such as the first fan rotor team. Parts teams are empowered to make important decisions relative to achieving the balanced design.


            I left you guessing with my reference to Blue Two visits. Well, US Air Force uniforms are blue, and the mechanics who work on the aircraft and the engines predominantly have a rank designated by two stripes on the sleeve. The US Air Force established a program for contractor personnel to visit air bases and work side by side with these « two stripers ». They call that program « Blue Two », Pratt & Whitney and the Lockheed team have taken full advantage of this program to send many of our people into Air Force engine shops and on the flight lines to work side by side with the two stripers. Our people spent a lot of time on these visits and they learned a lot about what it takes to keep an engine ready to fly. They even performed maintenance tasks in that cumbersome chemical warfare gear. The lessons learned were brought back to the drawing board for incorporation into the F119 design. This is the second element of getting all the musicians into one union - the « F-22 Team ».


            In summary, the F-22 has a very real and important role in our country’s future. The F119, the state-of-the-art, advanced technology engine, will provide the performance to help the F-22 succeed in its mission, the affordability that is so important in today’s economy, and the maintainability to help keep the F-22 ready for combat. The Integrated Product Development process tied together with a total F-22 Team commitment between the US Air Force, Lockheed Team, and Pratt & Whitney is the key to achieving this balance.



            That concludes my presentation. I thank you for your attention.



 Copyright www.stratisc.org - 2005 - Conception - Bertrand Degoy, Alain De Neve, Joseph Henrotin