Editing Lockheed Have Blue (section)

== Operational history ==

=== HB1001 ===
HB1001 made its first flight on 1 December 1977 at the hands of Lockheed test pilot, Bill Park. He would fly the next four sorties, all chased by a T-38 piloted by Major (later Lieutenant Colonel) Ken Dyson.<ref name=Crickmore_p20/> Dyson, an [[F-15 Eagle]] pilot, was previously approached by [[United States Air Force]] personnel about the project in 1976.<ref name=Crickmore_p16/> He made his first flight on HB1001 on 17 January 1978, chased by Park. In fact, the two would be the only test pilots of ''Have Blue'', alternating between the demonstrator and the chase plane.<ref name=Crickmore_p20>Crickmore 2003, p.&nbsp;20.</ref> Flight test results allowed engineers to refine the FBW system. At the same time, they verified predictions made earlier by aerodynamic engineers on the aircraft's behavior.<ref name=Crickmore_p20/>

Flight tests proceeded fairly smoothly until 4 May 1978, when HB1001 was making its 36th flight. The aircraft pitched up just as it made contact with the ground which forced the pilot, Bill Park, to abort the landing and make a second attempt. The impact had however been so hard that the landing gear had become jammed in a semi-retracted position. Efforts to lower the gear were unsuccessful and Bill Park was forced to climb again, and eject when his fuel ran out. The aircraft was destroyed on impact in the vicinity of the Groom Lake facility.<ref name=J&L_p232>Jenkins and Landis 2008, p.&nbsp;232.</ref> Park survived, but suffered a [[concussion]], forcing him to retire from further test flights.<ref name=Crickmore_p21>Crickmore 2003, p.&nbsp;21.</ref> Dyson, who was in the chase plane, recounted: "Just before touchdown the airplane pitched up... It seemed it slammed down on the ground real hard... He [Park] raised the gear on the go around, and when he tried to extend it on approach, only one of the mains and the nose wheel came down. All this time, gas was being consumed... I suggested he climb up to 10,000 feet for ejection... He started climbing, but the engine started [[Flameout|flaming out]], from the lack of fuel, so he ejected."<ref name=Crickmore_p21/>

=== HB1002 ===

At the time of the crash, HB1002 was almost complete, with the lessons learned from the HB1001 incorporated into the aircraft, including the rebuilding of the aft fuselage.<ref name=Crickmore_p19/> HB1002 was distinguished from the prototype in having a gray paint coat. It did not have the flight test instrumentation boom present on HB1001's nose. As the aircraft was used to test RCS returns, the unstealthy spin recovery chute was removed, and the aircraft was covered in radar-absorbent material.<ref name=J&L_p232/> It first flew on 20 July 1978 with Dyson at the controls, who would be the only pilot to fly the aircraft.<ref name=Crickmore_p22>Crickmore 2003, p.&nbsp;22.</ref>

HB1002 was lost on 11 July 1979 during the aircraft's 52nd flight. A [[Hydraulic fluid|hydraulic]] leak caused an engine fire, resulting in the loss of [[hydraulic pressure]], which in turn caused severe [[Flight dynamics (aircraft)|pitch]] [[oscillation]]s. The pilot ejected safely, and the aircraft was destroyed.<ref name=J&L_p233>Jenkins and Landis 2008, p.&nbsp;233.</ref> It was later discovered that an engine exhaust clamp had loosened, allowing the hot exhaust to migrate to the right engine compartment. The heat built up there, causing the hydraulic lines to fail.<ref name=Crickmore_p23>Crickmore 2003, p.&nbsp;23.</ref> The debris from both aircraft was secretly buried somewhere within the [[Nellis Air Force Base Complex]].<ref name=J&L_p233/> Despite the crashes, ''Have Blue'' was considered a success.<ref>Donald 2003, p.&nbsp;72.</ref>

=== ''Senior Trend'' ===
{{main|Lockheed F-117 Nighthawk}}
In October 1977, just prior to Phase 2 of the XST competition, Lockheed was tasked with exploring possible operational aircraft. Just a month later, on the day HB1001 was transported to Groom Lake, the Air Force awarded the company a contract under the code name ''Senior Trend''.{{refn|Quote: "The results of these studies were sufficiently promising that the Air Force issued a development contract on 16 November 1977 under the name ''Senior Trend''."<ref name=J&L_p233/>|group=N}} The Air Force wanted to exploit the revolutionary technologies developed during the ''Have Blue'' program.<ref>Crickmore 2003, p.&nbsp;25.</ref> [[Tactical Air Command]] ordered five full-scale development and twenty production aircraft.<ref name=J&L_p233/>

Based on the ''Have Blue'' demonstrators, ''Senior Trend'' aircraft were different from their predecessors in several aspects. The wings exhibited less sweep to resolve a [[Center of gravity|center-of-gravity]] problem discovered during tests. The front fuselage was shortened to give the pilot a better view, and the vertical stabilizers were canted outwards from the centerline.<ref name=J&L_p233/> Additionally, provisions were made to include two weapons bays, each of which would accommodate a single {{Convert|2000|lb|kg|adj=on}} [[laser-guided bomb]], or the [[B61 nuclear bomb|B61]] [[Tactical nuclear weapon|tactical nuclear bomb]].<ref name=J&L_p233/>

Beset by early construction problems, the first FSD aircraft was transferred to Groom Lake in May 1981 inside a C-5. Further problems, this time with fuel leaks, delayed the first flight.<ref name=J&L_p233/> Under the control of Harold Farley, the aircraft took off on 18 June for its maiden flight, eleven months after the July 1980 first flight originally envisaged.<ref name=J&L_p233/> The first production F-117A was delivered in 1982, and operational capability was achieved in October 1983; the 59th and last F-117A was delivered in 1990.<ref>Goodall 1992, p.&nbsp;29.</ref><ref>{{Cite web|title=F-117A Nighthawk : Overview|work=[[Federation of American Scientists]]|url=http://www.fas.org/programs/ssp/man/uswpns/air/attack/f117a.html|access-date=1 August 2011|archive-date=1 April 2014|archive-url=https://web.archive.org/web/20140401051317/http://www.fas.org/programs/ssp/man/uswpns/air/attack/f117a.html|url-status=dead}}</ref>