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 programmes. 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 programme 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) programme. In September 1983, while the AFTI programme 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 powerplants, the Pratt & Whitney YF119 and the General Electric YF120, were evaluated, and in April 1991 it was announced that the F-22 and F119 were the winning combination. The F119 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 manoeuvrability.
The Raptor is de-signed and built by Boeing, Lockheed Mar-tin and Pratt & Whitney. Boeing supplies the F-22s 2,000-lb titanium and composite wings and aft fuselage, integrates and tests the advanced avionics and is respon-sible for the training and life-support sys-tems.
Previously the designation for the Raptor was changed to F/A-22 to indicate the possible air-to-ground role of the aircraft. JDAM bombs can be carried in the internal weapon bay, while the optional external pylons offer a more flexible station for air-to-ground armament. However the U.S. Air Force changed the designation back to F-22 in December 2005, although it will still posess the secondary air-to-ground role.
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 the first production aircraft with the ability to super cruise – flying at supersonic speeds without the use of afterburners. 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. It will be a key component in the Global Strike Task Force, formed in 2001 to counter any threat worldwide. The USAF requirement is for 438 aircraft.
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. The first two Raptor fighters, Nos. 4001 and 4002, have only 80% of the required strength, partly the result of an aggressive weight-cutting program, and the No. 4003 airframe has been strengthened to make it 100% capable. The third F-22 was delivered to Edwards AFB in March 2000. The aircraft was about eight months behind schedule. The empty weight is still low enough to beat the operational requirements.
Raptor 4001 has been doing high speed tests such as loads and flutter but could not fully clear the envelope because of the lower strength, although it and ship No. 4002 have both exceeded 7g loads. The Air Force will only say that the required F-22 limit exceeds 7g. Raptor 4003 will provide full high speed clearance for subsequent aircraft, but will first spend several months on the ground at Edwards AFB because the reworked structure requires new ground vibration tests and other evaluations.
The nonstop delivery from Marietta, Ga., was the fourth flight of 4003 and lasted 4 hr. 50 min., including four aerial refuelings. By late 2001, there were eight F-22s flying.
A YF-22 being tested at Edwards reacted unexpectedly when a go round initiated a changed in its fly-by-wire control laws. After a few cycles of PIO, the aircraft belly-flopped onto the runway.
In January 2003, the Air Warfare Center at Nellis Air Force Base near Las Vegas, Nevada, received its first Raptor. It was the twelfth F-22 produced. The 422nd Test & Evaluation Squadron took on seven more F-22s for testing and training of the initial cadre of instructor pilots.
The 43rd Fighter Squadron became the first F-22 squadron when it received its first F-22 (then designated F/A-22) in the end of September in 2003. The unit of the 325th Fighter Wing carries out the training at Tyndall Air Force Base, Florida. In January 2004, the first pilot qualified at Tyndall AFB.
The 27th Fighter Squadron of the 1st Fighter Wing at Langley AFB became the first operational F-22 squadron when it received its first Raptor in Janaury 2005. The squadron was declared operational (initial operational capability) in December 2005 with 12 F-22A Raptors. Also based at Langley AFB, the 94th Fighter Squadron received its first two Raptors in March 2006. On January 19, 2007, the last of 40 F-22A Raptor for the 1st Fighter Wing was delivered to the 94th FS, equipping both fighter squadrons with 20 Raptors each.
N22YF (GE YF120 engines) rolled out at Palmdale 29 August 1990; first flight/ferry to Edwards AFB 29 September 1990; first air refuelling (11th sortie) 26 October 1990; Mach 1.58 supercruise’ (later exceeded) on 3 November 1990; first thrust-vectoring 15 November 1990; anti-spin parachute fitted for high AoA tests with thrust-vectoring; last flight 28 December 1990 — total 43 sorties/52.8hr.
Second prototype: N22YX (P&W F119 engine) first flight Palmdale-Edwards 30 October 1990; launched first AIM-9M Sidewinder on 28 November 1990 and AIM-120 AMRAAM on 20 December 1990; achieved Mach 1.8 26 December 1990; last flight 28 December 1990 — total 31 sorties/38.8 hrs.
Summary demonstrated thrust vectoring, including 100deg/sec roll rate at 120kt (222km/h; 138mph); Mach 2 speed with afterburning. Aircraft in storage at Edwards AFB from January 1991.
Wing span 43ft 0in (13.11m)
Length overall 64ft 2in (19.56m)
Height overall 17ft 8.875in (5.41m)
Engines: two Pratt & Whitney F119-P-100 turbofan, 155.69 kN (35,000 lb st) with afterburning
Length 18.92m (62 ft 1 in)
Height 5.00m (16 ft 5 in)
Wing span 13.56m (44ft 6 in)
Empty weight: 13.608+ kg (30,000+ lb)
Max Take-Off Weight: 26.308 kg (58,000 lb)
Max level speed at optimum altitude: Mach 1.58 in supercruise
Max level speed at 30,000 ft (9145m) Mach 1.7 in afterburning mode
Service ceiling: 15,240+m (50,000+ ft)
G limit: +7.9
Armament: one 20mm M61A2 Vulcan six-barrel gun with 480 rounds; 2 AIM-9X Sidewinder IR-guided missiles in internal side bays. Up to 6 AIM-120C or 4 AIM-120A AMRAAM missiles in internal fuselage weapon bays or 2 AIM-120C AMRAAMs and 2 GBU-32 JDAM bombs or 2 GBU-30 JDAM bombs. Up to four fuel tanks and up to 8 missiles on optional external hardpoints.
Lockheed F-22 Raptor