F-22 Raptor F119-PW-100 Engine
The F-22 incorporates a pair of new, higher thrust-to-weight engines, the Pratt & Whitney F119-PW-100, which is designed for efficient supersonic operation without afterburner (called supercruise), and with increased durability over current engines. Advanced technologies incorporated in the F119 include integrated flight-propulsion controls and two-dimensional, thrust-vectoring engine nozzles, which will give the F-22 unprecedented aircraft maneuverability. Development of the F119 was conducted at Pratt & Whitney's West Palm Beach, FL, facility, while production takes place at the company's factories in Middletown, CT. Pratt & Whitney built 27 flightworthy engines during
Designed for efficient supersonic operation without afterburner use and with increased durability over today's engines, the F119 is a very high thrust-to-weight ratio engine. Advanced technologies in the F119 include integrated flight-propulsion controls and two-dimensional, thrust-vectoring engine nozzles. The F119 incorporates technology advances developed and verified in joint U.S. Air Force/Pratt &Whitney research programs and for other advanced fighter engines. It was designed using the "integrated product development" approach to ensure a balance between performance, safety and reliability, maintainability and low life-cycle cost. In addition, it has significantly fewer and more durable components than previous fighter engines.
The F119-PW-100 is a revolutionary advance in fighter aircraft propulsion. The F119 engine develops more than twice the thrust of current engines under supersonic conditions, and more thrust without afterburner than conventional engines with afterburner.
Each F-22 will be powered by two of these 35,000-pound-thrust-class engines. By comparison, the engines powering the Air Force's current F-15 and F-16 fighters have thrust ratings ranging from 23,000 to 29,000 pounds.
Jet engines achieve additional thrust by directly injecting fuel at the engine exhaust. The process, called afterburner, gives the aircraft a rocket-like boost as the fuel ignites in the exhaust chamber. The tradeoff is higher fuel consumption, a greater amount of heat, and consequently, greater visibility to the enemy.
The F119 can push the F-22 to supersonic speeds above Mach 1.4 even without the use of afterburner, which gives the fighter a greater operating range and allows for stealthier flight operation. The product of more than 40 years' research into high-speed propulsion systems, the F119 is proof that high-technology doesn't have to be complicated.
Performance of the F119 engine has generally been excellent in testing. Full-scale airframe static testing and the first of three (originally four) planned fatigue lifetimes of testing have been completed and the second fatigue life testing is nearly complete. The program now plans to complete three fatigue lifetimes prior to the completion of the ongoing engineering and manufacturing development phase in November 2005. Expansion of flight test into the high-speed, high-G load regions of the performance envelope is ongoing.
A balanced approach to the design process, using a team approach called Integrated Product Development (IPD), led to an engine as innovative in its reliability and support as in its performance. Assemblers and flight line mechanics participated in the F119's design from its inception. The result is that ease of assembly, maintenance and repair are designed into the engine.
The F119 has 40 percent fewer major parts than current fighter engines, and each part is more durable and does its job more efficiently. Computational fluid dynamics (CFD), the study of airflow using advanced computers, led to the design of engine turbomachinery of unprecedented efficiency, giving the F119 more thrust with fewer turbine stages.
The F119 cuts requirements for support equipment and labor by one-half, which also saves precious space in airlifters in combat zone deployments. The F119 will require 75 percent fewer shop visits for routine maintenance than its predecessors.
- Integrally bladed rotors: In most stages, disks and blades are made from a single piece of metal for better performance and less air leakage.
- Long chord, shroudless fan blades: Wider, stronger fan blades eliminate the need for the shroud, a ring of metal around most jet engine fans. Both the wider blades and shroudless design contribute to engine efficiency.
- Low-aspect, high-stage-load compressor blades: Once again, wider blades offer greater strength and efficiency.
- Alloy C high-strength burn-resistant titanium compressor stators: Pratt & Whitney's innovative titanium alloy increases stator durability, allowing the engine to run hotter and faster for greater thrust and efficiency.
- Alloy C in augmentor and nozzle: The same heat-resistant titanium alloy protects aft components, permitting greater thrust and durability.
- Floatwall combustor: Thermally isolated panels of oxidation-resistant high cobalt material make the combustion chamber more durable, which helps reduce scheduled maintenance.
- Fourth-generation full-authority digital electronic engine control (FADEC): Dual-redundant digital engine controls - two units per engine, two computers per unit - ensure unmatched reliability in engine control systems. The same experience that introduced full-authority digital control to fighter engines works with the aircraft system to make engine and aircraft function as a single flight unit.
- No visible smoke: Reduces the possibility of an enemy visually detecting the F-22.
- Improved Supportability: All components, harnesses, and plumbing are located on the bottom of the engine for easy access, all line replaceable units (LRUs) are located one deep (units are not located on top of one another), and each LRU can be removed with just one of the six standard tools required for engine maintenance.
F119/F-22 Engine Nozzle
The F119 engine nozzle for the F-22 is the world's first full production vectoring nozzle, fully integrated into the aircraft/engine combination as original equipment.
The two-dimensional nozzle vectors thrust 20 degrees up and down for improved aircraft agility. This vectoring increases the roll rate of the aircraft by 50 percent and has features that contribute to the aircraft stealth requirements.
Heat-resistant components give the nozzles the durability needed to vector thrust, even in afterburner conditions.
With precision digital controls, the nozzles work like another aircraft flight control surface. Thrust vectoring is an integrated part of the F-22's flight control system, which allows for seamless integration of all components working in response to pilot commands.
The nozzle is manufactured at Pratt & Whitney's West Palm Beach facility, home to the company's military engine design and prototype construction.
Engine Assembly and Test Facilities
Pratt & Whitney's West Palm Beach, Fla., facility is the focal point for its military engine development activities. But given the Integrated Product Development process, which gives manufacture, assembly, and maintenance personnel a larger role in engine design, F119 development activities have also incorporated its eventual producers at company facilities in Middletown, East Hartford, and New Haven, Conn.; North Berwick, Me.; and Columbus, Ga.
Sea-level testing was conducted at the West Palm Beach facility. Extensive altitude testing was done at the Air Force's Arnold Engineering Development Center, Arnold AFB, Tullahoma, Tenn.
Most F119 assembly work will be conducted in Middletown, Conn., where Pratt & Whitney employs 3,000 people in the manufacture of combustors, engine cases, and major rotating parts. Middletown is a two-million square foot facility on 1,100 acres.
Components for the 26 F119 engines to be built during the current Engineering and
Manufacturing Development (EMD) phase are being produced in Middletown. At the conclusion of the proof-of-concept program, the facility and its people will have gained engine production experience and will be ready to gear up for full F119 production in support of the F-22 and Joint Strike Fighter (JSF) programs.
Components will be made by suppliers in states across the nation and at these Pratt & Whitney facilities: East Hartford, Conn.: Pratt & Whitney employs 7,800 employees in this 5.2-million square foot facility, which houses Large Commercial Engines headquarters, commercial engineering, marketing, and product support, overhaul and repair operations and manufacturing facilities. The facility specializes in single-crystal turbine blades, fans, and compressor blades, as well as commercial engine production.
- North Haven, Conn.: The 1,600 employees in this 800,000-square-foot facility make turbine and compressor blades and vanes.
- North Berwick, Me.: Here, 1,500 employees in an 880,000 square-foot facility manufacture blades, vanes, bearing compartments, and stators.
- Columbus, Ga.: The 250 employees at Pratt & Whitney's newest manufacturing plant forge disks and other engine components.
In the Engineering and Manufacturing Development (EMD) phase of the program, Pratt & Whitney designed, developed, and qualified three products: 26 flight test engines, the F119 support system, and the F119 training system.
Plans call for the production of 1,000 F119 engines. This number will provide engines for the 438 planned aircraft (two per aircraft) plus sufficient spares.
F-22 Airframe Mounted Accessory Drive (AMAD)
Built by Boeing, the F-22 Airframe-Mounted Accessory Drive (AMAD) transfers shaft power from the Air Turbine Starter System (ATSS) to the F119 engines for engine starts, and from the engines to a generator and hydraulic pumps for the electrical and hydraulic systems.
The AMAD transmits power required by the high-performance F-22 throughout the flight envelope and incorporates a high-reliability lubrication system that services the AMAD-mounted generator and ATSS as well as gearbox components.
The Boeing-developed F-22 engine trailer (designated A/M32M-34) is a piece of ground support equipment that is required for installation and removal of the Pratt & Whitney F119 engines. The trailer also supports the engine for on-base towing, air, and truck shipment. For air and truck shipment a shipping adapter (a support frame that fits over the top of the engine and attaches to the trailer to secure the engine) is also required.
During engine installation, the trailer provides a six-axis (vertical, lateral, pitch, roll, and yaw) adjustment capability to precisely align the engine to the aircraft. Fine adjustments in the vertical and lateral directions are also provided for load transfer of the engine to/from the aircraft.
Once aligned, the engine slides from the trailer's rails directly to a similar set of extension rails placed in the aircraft's engine bay. From there, the engine is pushed on to the engine mounts The lower segments of two of the aircraft's engine bay frames (numbers 5 and 6) drop down to allow for engine fitting.
There are only eight connections that have to be made between the engine and the aircraft, and with the drop out links, maintainers will be able to remove and replace an engine in approximately 75 minutes.
The engine trailer is approximately 14 feet in length and 6 feet wide. When fully lowered by means of its mechanically actuated scissors lift assembly, the trailer's height is only 38 inches. Maximum height is 5 feet. The empty weight of the trailer is 3,400 pounds. The trailer's maximum payload capacity is 7,500 pounds.