Without doubt, the most exciting combat aircraft of the early twenty-first century is the Lockheed Martin F-22 Raptor. In the late 1970s, the US Air Force identified a requirement for 750 examples of an Advanced Tactical Fighter (ATF) to replace the F-15 Eagle. Flown by a single pilot, it must be able to survive in an environment filled with people, both in the air and on the ground, whose sole purpose is to destroy it. To test the concepts that would eventually be combined in the ATF, the US AF initiated a series of parallel research programs. The first was the YF-16 control-configured vehicle (CCV) which flew in 1976-77 and demonstrated the decoupled control of aircraft flight path and attitude; in other words, the machine could skid sideways, turn without banking, climb or descend without changing its attitude, and point its nose left or right, or up or down, without changing its flight path. Other test vehicles involved in the ATF program included the Grumman X-29, which flew for the first time in December 1984 and which was designed to investigate forward-sweep technology, and an F-111 fitted with a mission adaptive wing (MAW) - in other words, a wing capable of reconfiguring itself automatically to mission requirements.
Flight testing of all these experimental aircraft came under the umbrella of the USAF's Advanced Fighter Technology Integration (AFTI) program. In September 1983, while the AFTI program was well under way, the USAF awarded ATF concept definition study contracts to six American aerospace companies and, of these, two - Lockheed and Northrop - were selected to build demonstrator prototypes of their respective proposals. Each company produced two prototypes, the Lockheed YF-22 and the Northrop YF-23, and all four aircraft flew in 1990. Two different power plants, the Pratt & Whitney YF1-19 and the General Electric YF-120, were evaluated, and in April 1991 it was announced that the F-22 and F119 were the winning combination. The F-119 advanced technology engine, two of which power the F-22, develops 155kN and is fitted with two-dimensional convergent/ divergent exhaust nozzles with thrust vectoring for enhanced performance and maneuverability. The F-22 passed milestone II in 1991. At that time, the Air Force planned to acquire 648 F-22 operational aircraft at a cost of $86.6 billion. After the Bottom Up Review, completed by DOD in September 1993, the planned quantity of F-22s was reduced to 442 at an estimated cost of $71.6 billion.
The first definitive F-22 prototype was rolled out at the Lockheed Martin plant at Marietta, Georgia, on 9 April 1997. There were numerous problems with this aircraft, including software troubles and fuel leaks, and the first flight was delayed to 7 September 1997. The second prototype first flew on 29 June 1998. By late 2001, there were eight F-22s flying. The F-22 combines many stealth features. Its air-to-air weapons, for example, are stored internally; three internal bays house advanced short-range, medium-range and beyond-visual-range air-to-air missiles. Following an assessment of the aircraft's combat role in 1993, it was decided to add a ground-attack capability, and the internal weapons bay is also capable of accommodating 454kg GBU-32 precision guided missiles.
The F-22 is designed for a high sortie rate, with a turnaround time of less than 20 minutes, and its avionics are highly integrated to provide rapid reaction in air combat, much of its survivability depending on the pilot's ability to locate a target very early and take it out with a first shot. The F-22 was designed to meet a specific threat, which at that time was presented by large numbers of highly agile Soviet combat aircraft, its task being to engage them in their own airspace with beyond-visual-range weaponry.