The Lockheed/Boeing/General Dynamics YF-22 is an American single-seat, twin-engine, stealth fighter technology demonstrator prototype designed for the United States Air Force (USAF).

The design team, with Lockheed as the prime contractor, was a finalist in the USAF's Advanced Tactical Fighter (ATF) competition, and two prototypes were built for the demonstration/validation phase.

Lockheed, Boeing and General Dynamics proposed and built the YF-22, which, although marginally slower and having a larger radar cross-section, was more agile than the YF-23.

[1] The USAF sent out the ATF request for information (RFI) to the aerospace industry in May 1981 to explore what the future fighter aircraft could look like, and subsequently established a Concept Development Team (CDT) to analyze the results.

[2] Eventually code-named "Senior Sky", the ATF at this time was still in the midst of requirements definition with both air-to-air and air-to-ground missions in consideration, and consequently there was substantial variety in the responses from the industry.

[3][4] In 1983, the ATF Concept Development Team became the System Program Office (SPO) at Wright-Patterson Air Force Base.

[7] In September 1985, the Air Force sent out technical request for proposals (RFP) to a number of aircraft manufacturing teams for demonstration and validation (Dem/Val).

In addition to the ATF's demanding technical requirements, Dem/Val also placed a great deal of importance on systems engineering, technology development plans, and risk mitigation.

Although its analytical tools were initially not able to calculate for such shapes, good empirical results from radar range testing at Helendale, California, gave Lockheed confidence in designing a stealthy aircraft with smooth, curved surfaces, thus greatly improving its aerodynamic characteristics.

As Lockheed gradually became able to analyze curved shapes,[N 2] the final design submitted for Dem/Val, designated Configuration 090P, would have an arrowhead-like forward fuselage shape, swept trapezoidal wings, four empennage tail surfaces, S-shaped inlet ducts obscuring the engine face, and an internal rotary missile launcher.

[3] In addition to the change in aircraft design, Lockheed also shifted much more engineering talent and manpower to its ATF effort, appointing Sherman Mullin as the program manager, and had its draft proposals aggressively red-teamed by a group led by retired Air Force general Alton D.

[11] The ATF RFP would see some alterations after its first release; the SPO drastically increased all-aspect stealth requirements in December 1985 after discussions with Lockheed and Northrop regarding their experiences with the Have Blue/F-117 and ATB/B-2, and the requirement for flying technology demonstrator prototypes was added in May 1986 due to recommendations from the Packard Commission, a federal commission by President Ronald Reagan to study Department of Defense procurement practices.

The two teams, Lockheed/Boeing/General Dynamics and Northrop/McDonnell Douglas, were awarded $691 million contracts in FY 1985 dollars (~$1.66 billion in 2023) and would undertake a 50-month demonstration phase, culminating in the flight test of the two teams' prototypes, the YF-22 and the YF-23; Pratt & Whitney and General Electric had earlier been awarded contracts to develop the competing prototype propulsion systems with the designations YF119 and YF120 respectively.

Boeing's design was large and long with a chin-mounted inlet, trapezoid wings, V-tail empennage surfaces (deemed sufficient due to the high operating speed), and palletized internal weapons.

By early 1987, the design had evolved into Configuration 095, which replaced the rotary launcher with a flatter weapons bay to reduce volume and drag, and the shapes of the forward fuselage and leading-edge root extensions were recontoured to prevent uncontrollable pitch-up moments.

[24] By mid-1987, detailed weight analysis of Configuration 595/1095 revealed that it was overweight by 9,000 lb (4,100 kg) even if it could still nominally meet maneuver parameters.

[N 7][28] Various different layouts were explored and after an intensive three-month effort, the team chose a new design, Configuration 614/1114, as the starting point in late 1987 with shoulder-mounted inlets and diamond-like delta wings similar to General Dynamics' design, and four empennage tail surfaces; notably, the diamond-like delta's aerodynamic characteristics approached the original swept trapezoidal profile's while offering much lower structural weight due to the longer root chord.

[24] Formally designated as the YF-22A, the first aircraft (PAV-1, serial number 87-0700, N22YF), with the GE YF120 engine,[34][35] was rolled out on 29 August 1990[22][36] and first flew on 29 September 1990, taking off from Palmdale piloted by David L.

After an internal competition and extensive wind tunnel testing, the team chose to incorporate variable-sweep wings in August 1989.

[41] The Lockheed team would submit its NATF design along with its ATF full-scale development proposal in December 1990, although the Navy would withdraw from the program shortly afterwards due to cost.

[42] The airframe has large diamond-like delta wings with leading edge swept back 48°, shoulder-mounted inlets, three internal weapons bays, and four empennage surfaces: canted vertical tails with rudders and all moving horizontal stabilizers.

The two-dimensional thrust vectoring nozzles reduce the infrared signature by flattening the exhaust plume and facilitating its mixing with ambient air.

Because the NATF needed lower landing speeds than the F-22 for aircraft carrier operations while still attaining Mach 2-class speeds, the design would have incorporated variable-sweep wings; furthermore, the Navy placed greater emphasis on loiter time for fleet air defense rather than supercruise, so the variable-sweep wings also improved endurance.

Lockheed and Boeing would leverage aspects of the design, such as the variable-sweep wings, for several concepts for the Navy's Advanced-Attack (A-X) program, which later became the Advanced Attack/Fighter (A/F-X) program with added fighter capability, the successor to the canceled A-12 Avenger II; however, A/F-X would also be canceled as a result of the 1993 Bottom-Up Review due to post-Cold War budget pressure.

[55][56] Flight testing also demonstrated that the YF-22 with its thrust vectoring nozzles achieved pitch rates more than double that of the F-16 at low-speed maneuvering as well as having excellent high angle-of-attack characteristics, with trimmed alpha of over 60° flown.

[60] On 23 April 1991, the Lockheed team was announced by Secretary of the Air Force Donald Rice as the winner of the ATF competition.

Contrary to the F-117 Nighthawk, which was initially difficult to control because of small vertical stabilizers, the YF-22 had its fin area over-specified by Lockheed.

[72] Data from Miller,[75] Pace,[76] Baker,[77] Sweetman,[78] and Aronstein & Hirschberg[79] (note, some specifications are estimated)General characteristics Performance Armament Provisions made for: Related development Aircraft of comparable role, configuration, and era