Editing Lockheed YF-22 (section)

== Operational history ==

=== Evaluation ===
[[File:YF-22 and YF-23.jpg|thumb|The YF-22 (foreground) and YF-23 (background)|alt=Two different jet aircraft in flight towards right of screen.]]
Testing began with the first flight of PAV-1 on 29 September 1990. During the 18-minute flight, PAV-1 reached a maximum speed of {{Convert|250|kn}} and a height of {{Convert|12500|ft}}, before landing at [[Edwards AFB]].<ref name="YF-22 first flight"/> Following the flight, test pilot Dave Ferguson said that the remainder of the YF-22 test program would be concentrated on "the manoeuvrability of the aeroplane, both supersonic and subsonic".<ref name="YF-22 first flight"/>

During the flight test program, unlike the YF-23, weapon firings and high (60°) angle of attack (AoA, or high-alpha) flights were carried out on the YF-22.<ref name="Will p. 6"/> Although not a program requirement, the aircraft fired [[AIM-9 Sidewinder]] and [[AIM-120 AMRAAM]] missiles from internal weapon bays.<ref name="Will p. 6"/><ref>[https://go.gale.com/ps/i.do?p=AONE&sw=w&issn=08890404&v=2.1&it=r&id=GALE%7CA9371744&sid=googleScholar&linkaccess=abs "YF-23 would undergo subtle changes if it wins competition".] ''Defense Daily'', pp. 62–63, 14 January 1991.</ref> 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. The first prototype, PAV-1 with the General Electric engines, achieved Mach&nbsp;1.58 in supercruise on 3 November 1990, while PAV-2 with the Pratt & Whitney engines reached a maximum supercruise speed of Mach&nbsp;1.43 on 27 December 1990; maximum speed was in excess of Mach 2.0.<ref>Jenkins and Landis 2008, p.&nbsp;236.</ref><ref name="Goodall_p102-3">Goodall 1992, pp.&nbsp;102–103.</ref> Flight testing continued until 28&nbsp;December&nbsp;1990, by which time 74 flights were completed and 91.6 airborne hours were accumulated.<ref name="Williams 2002, pp. 5–6"/><ref>{{cite AV media |url=https://www.youtube.com/watch?v=nY0j3dmlHec |title=YF-22 – Road to the Raptor with Tom Morgenfeld, Test Pilot |date=17 April 2022 |publisher=Western Museum of Flight |location=Torrance, California |access-date=30 June 2023 |people=Morgenfeld, Thomas A.}}</ref> Following flight testing, the contractor teams submitted proposals for ATF full-scale development, with the Lockheed team's PSC F-22 design being significantly refined and evolving to Configuration 638 for its submission.<ref name=Miller_p38-9>Miller 2005, pp.&nbsp;38–39.</ref>

On 23&nbsp;April&nbsp;1991, the Lockheed team was announced by [[United States Secretary of the Air Force|Secretary of the Air Force]] [[Donald Rice]] as the winner of the ATF competition. The Lockheed team was rated higher on technical aspects, was considered lower risk (the YF-22 flew considerably more hours and sorties than its counterpart), and was considered to have more effective program management.<ref>Jenkins and Landis 2008, p.&nbsp;234.</ref><ref>Miller 2005, p. 38.</ref> Both designs met or exceeded all performance requirements; the YF-23 was stealthier and faster, but the YF-22 was more agile.<ref name="Goodall_p110">Goodall 1992, p.&nbsp;110.</ref> It was speculated in the aviation press that the Lockheed design was also seen as more adaptable to the Navy's NATF, but the Navy abandoned NATF by FY 1992.<ref name="Will p. 6">Williams 2002, p.&nbsp;6.</ref><ref name=Miller_p76>Miller 2005, p.&nbsp;76.</ref> Instead of being retired, as with the case of PAV-1, PAV-2 subsequently flew sorties following the competition – it amassed another 61.6 flying hours during 39 flights.<ref name="Will p. 6"/> On 25&nbsp;April&nbsp;1992, the aircraft sustained serious damage during a [[go-around]] attempt as a result of [[pilot-induced oscillation]]s. It was repaired but never flew again, and instead served as a static test vehicle thereafter.<ref name="Will pp. 6–7">Williams 2002, pp.&nbsp;6–7.</ref><ref>{{Cite journal|last=Warwick|first=Graham|title=Software suspected in YF-22 ATF accident|journal=[[Flight International]]|location=London|publisher=Reed Business Information|issue=4317|volume=141|page=12|date=6–12 May 1992|url=http://www.flightglobal.com/pdfarchive/view/1992/1992%20-%201156.html|access-date=24 June 2011|archive-url=https://web.archive.org/web/20110925145110/http://www.flightglobal.com/pdfarchive/view/1992/1992%20-%201156.html|archive-date=25 September 2011|issn=0015-3710 |ref=none}}</ref> In 1991, it was anticipated that 650 production F-22s would be procured.<ref>{{Cite news |last1=Pearlstein |first1=Steven |author-link=Steven Pearlstein |last2=Gellman |first2=Barton |author-link2=Barton Gellman |date=24 April 1991 |title=Lockheed Wins Huge Jet Contract; Air Force Plans to Buy 650 Stealth Planes At $100&nbsp;million Each |url=https://www.washingtonpost.com/archive/politics/1991/04/24/lockheed-wins-huge-jet-contract/89170285-d2c6-4c36-bb23-74dfae672626/ |newspaper=The Washington Post}}</ref>

=== F-22 production ===
{{Main|Lockheed Martin F-22 Raptor}}
[[File:F-22 Raptor resumes flight testing - 030328-F-0000C-001.jpg|thumb|F/A-22 Raptor test and training flight operations resumed here March 22 after a brief delay following a nose-gear-retraction incident in 2003.]]

As the Lockheed team won the ATF competition, it was awarded the full-scale development, or [[Manufacturing readiness level#Definitions|Engineering & Manufacturing Development]] (EMD) contract in August 1991 initially worth about $11&nbsp;billion (~${{Format price|{{Inflation|index=US-GDP|value=11000000000|start_year=1991}}}} in {{Inflation/year|US-GDP}}), which would ultimately allow it to proceed with production of operational aircraft. The EMD/production design would be further refined and evolve into Configuration 645.<ref name="Hehs1998P2"/> The EMD initially called for seven single-seat F-22A and two twin-seat F-22Bs, although the latter was eventually canceled to save on development costs and the orders were converted to single-seaters. On 9&nbsp;April&nbsp;1997, the first of these, ''Spirit of America'', was rolled out. During the ceremony, the F-22 was officially named "Raptor". Due to limited funding, the first flight, which had previously been scheduled for mid-1996, occurred on 7&nbsp;September 1997.<ref name="Will pp. 6–7"/> Flight testing for the F-22 continued until 2005, and on 15&nbsp;December&nbsp;2005 the USAF announced that the Raptor had reached its [[initial operational capability]] (IOC); with the collapse of the Soviet Union and the Department of Defense focused on counterinsurgency at that time, F-22 production only reached 195 aircraft — 187 of them operational models — and ended in 2011.<ref>{{Cite web|url=https://www.af.mil/News/story/storyID/123013572/ |title=F-22A Raptor goes operational |work=U.S. Air Force |date=15 December 2005 |access-date=24 June 2011 |archive-url=https://archive.today/20120723113239/http://www.af.mil/news/story.asp?storyID=123013572 |archive-date=23 July 2012 |url-status=live }}</ref><ref name="combataircraft">Parsons, Gary. [http://www.combataircraft.net/view_article.asp?ID=4994 "Final F-22 Delivered"]. {{Webarchive|url=https://web.archive.org/web/20160313044134/http://www.combataircraft.net/view_article.asp?id=4994|date=13 March 2016}}. ''Combat Aircraft Monthly'', 3 May 2012. Retrieved 10 April 2014.</ref>

In many respects, the YF-22s were different from EMD/production F-22s as the design progressed from relatively immature Configuration 632/1132 to the final Configuration 645. Contrary to the [[Lockheed F-117 Nighthawk|F-117 Nighthawk]], which was initially difficult to control because of small [[vertical stabilizer]]s, the YF-22 had its fin area over-specified by Lockheed. Therefore, the company reduced the size of those on F-22s by 20–30 percent. Lockheed and its partners recontoured the shape of the wing and [[stabilator]] trailing edges to improve aerodynamics, strength, and stealth characteristics; the wing and stabilitor sweep was reduced by 6° from 48°. The shapes of the [[radome]] and fuselage were changed to improve radar performance and aerodynamics. The dedicated airbrake was eliminated in favor of feathering control surfaces using the control laws. The systems arrangement and structural design were refined. Finally, to improve pilot visibility, the canopy was moved forward {{convert|178|mm|in|0|order=flip}}, and the engine inlets were moved rearward {{convert|356|mm|in|0|order=flip}}.<ref>Williams 2002, p. 5.</ref><ref>Pace 1999, pp.&nbsp;12–13.</ref><ref name="Hehs1998P2"/>