The F-22 Raptor is a fifth generation stealth fighter aircraft. It was originally envisioned as an air superiority fighter for use against the Soviet Air Force, but is equipped for ground attack, electronic warfare and signals intelligence roles as well. Faced with a protracted development period, the prototype aircraft was designated YF-22 and, as F/A-22 during the three years before formally entering United States Air Force service in December 2005 as the F-22A. Lockheed Martin Aeronautics is the prime contractor and is responsible for the majority of the airframe, weapon systems and final assembly of the F-22. Along with Lockheed Martin, partner Boeing Integrated Defense Systems provides the wings, aft fuselage, avionics integration, and all of the pilot and maintenance training systems.he Advanced Tactical Fighter (ATF) contract was a demonstration and validation program undertaken by the United States Air Force to develop a next-generation air superiority fighter to counter emerging worldwide threats, including development and proliferation of Soviet-era Su-27 'Flanker'-class fighter aircraft.In 1981, USAF developed a requirement for a new air superiority fighter intended to replace the capability of the F-15 Eagle. It was envisaged that the ATF would incorporate emerging technologies including advanced alloys and composite material, advanced fly-by-wire flight control systems, higher power propulsion systems, and low-observable/stealth technology.A request for proposal (RFP) was issued in July 1986, and two contractor teams, Lockheed/Boeing/General Dynamics and Northrop/McDonnell Douglas were selected in October 1986 to undertake a 50 month demonstration/validation phase, culminating in the flight test of two prototypes, the YF-22 and the YF-23.The original Boeing Advanced Tactical Fighter concept, 1986.The original Boeing Advanced Tactical Fighter concept, 1986.Following a hard-fought fly-off competition, in August 1991 the YF-22 was declared the winner and Lockheed was awarded the contract to develop and build the Advanced Tactical Fighter.Intended to be the leading American advanced tactical fighter in the early part of the 21st century, the Raptor is the world's most expensive fighter to date with a cost of about US$120 million per unit, or US$361 million per unit when development costs are added.As of April 2005 the total development and production cost of the program is at least US$70 billion, and the number of planes to be built has dropped to 438, then 381, and now to 180, down from the initial requirement of 750.Part of the reason for the decrease in the requirement is that the F-35 Lightning II uses much of the technology used on the F-22, but at a much more affordable price. To a large extent the cost of these technologies is only lower for the F-35 because they have already been developed for the F-22.The production model was formally named F-22 "Raptor" when the first production-representative plane was unveiled on 9 April 1997 at Lockheed-Georgia Co., Marietta, Georgia. First flight occurred on 7 September 1997.
The dual afterburning Pratt & Whitney F119-PW-100 turbofans incorporate thrust vectoring. Thrust vectoring is in the pitch axis only, with a range of ±20 degrees. The maximum thrust is classified, though most sources place it at about 35,000 lbf (156 kN) per engine. Maximum speed is estimated to be Mach 1.72 in supercruise mode and without external weapons; with afterburners, it is "greater than Mach 2.0" (2,120 km/h), according to Lockheed Martin. The Raptor can easily exceed its design speed limits, particularly at low altitudes; max-speed alerts help prevent the pilot from exceeding the limits. General John P. Jumper, former U.S. Air Force Chief of Staff, flew the Raptor faster than Mach 1.7 without afterburners on January 13, 2005. The absence of variable intake ramps may make speeds greater than Mach 2.0 unreachable, but there is no evidence to prove this. Such ramps would be used to prevent engine surge, but the intake itself may be designed to prevent this. Former Lockheed Raptor chief test pilot Paul Metz stated that the Raptor has a fixed inlet. Metz has also stated that the F-22 has a top speed greater than 1600 mph (Mach 2.42) and its climb rate is faster than the F-15 Eagle due to advances in engine technology, despite the F-15's thrust-to-weight ratio of about 1.2:1, with the F-22 having a ratio closer to 1:1.The F-22 is highly maneuverable, at both supersonic and subsonic speeds. The usage of the F-22's thrust vectoring nozzles allows the aircraft to turn tightly, and perform extremely high alpha (angle of attack) maneuvers such as the J-Turn (or Herbst maneuver), Pugachev's Cobra and the Kulbit, though the J-Turn is more useful in combat.The F-22 is also capable of maintaining a constant angle of attack of over 60°, yet still having some control of roll.Cruise altitude is a huge factor in performance.
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