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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.
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 turbo machinery
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 air lifters in combat
zone deployments. The F119 will require 75 percent fewer shop
visits for routine maintenance than its predecessors.
Pratt
& Whitney F119-PW-100 Turbofan Engine (photograph)
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Integrally bladed rotors: In most
stages, disks and blades are made from a single piece of metal
for better performance and less air leakage.
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Long chord, shroud less 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 shroud less design contribute to engine efficiency.
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Low-aspect, high-stage-load compressor
blades: Once again, wider blades offer greater strength and
efficiency.
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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.
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Alloy C in augmentor and nozzle: The
same heat-resistant titanium alloy protects aft components,
permitting greater thrust and durability.
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Floatwall combustor: Thermally
isolated panels of oxidation-resistant high cobalt material
make the combustion chamber more durable, which helps reduce
scheduled maintenance.
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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.
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No visible smoke: Reduces the
possibility of an enemy visually detecting the F-22.
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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.
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.
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Engine
Assembly and Test Facilities
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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.
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North Haven, Conn.: The 1,600
employees in this 800,000-square-foot facility make turbine
and compressor blades and vanes.
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North Berwick, Me.: Here, 1,500
employees in an 880,000 square-foot facility manufacture
blades, vanes, bearing compartments, and stators.
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Columbus, Ga.: The 250 employees at
Pratt & Whitney's newest manufacturing plant forge disks
and other engine components.
In the current Engineering and Manufacturing Development (EMD)
phase of the program, Pratt & Whitney will design, develop,
and qualify three products: 26 flight test engines, the F119
support system, and the F119 training system.
The current 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.
above info
taken directly from Boeing
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