Successfully kept secret for nearly 15 years, the Lockheed F-117A was the
winning submission for the 'black' XST (Experimental Stealth Technology) competition of 1975-76 sponsored by the US Defense Advanced Research Projects Agency. Both Northrop and Lockheed were contenders for the programme, but in 1976 Lockheed was awarded the contract and built two technology demonstrator prototypes under a programme codenamed 'Have Blue'. Powered by General Electric CJ610 turbojet engines, the first XST made its initial flight in December 1977 from Groom Lake, Nevada, piloted by William C. Park, but both prototypes ultimately crashed, one in May 1978 and the other in 1980.
Promising test results led to the development of two scaled-up YF-117A-LO prototypes which were followed by 57
production F-117As ordered in batches during the fiscal years 1980 to 1986 plus 1988. The first pre-production aircraft flew for the first time on 18 June 1981, and the first F-117A was handed over to the USAF in August 1982. Despite much worldwide speculation, the air force resisted confirming the existence of the programme until November 1988 when they released a rudimentary and misleading photograph of the aircraft, and confirmed the designation. The next logical 'F number' should have been the F-19, and many agencies used this for some time when identifying the spectral aircraft. The USAF had allocated F-112 to F-116 to Soviet fighters acquired clandestinely for evaluation, and the designation F-117 was thought to be in use for the same purposes and consequently attracted less attention. The F-117A was declared operational
in 1983, but the aircraft flew only at night from its secret base at Tonopah, 225km north-west of Las Vegas, Nevada, to preserve programme secrecy, until late in 1989 when daytime flying began. Two aircraft were lost in accidents in July 1986 and October 1987 and these were attributed to pilot disorientation associated with fatigue.
F-117As, reportedly nicknamed 'Wobblin Goblin', but more usually referred to by its pilot as the 'Black Jet' and officially named Night Hawk, first went into action in December 1989 as part of Operation Just Cause mounted by the US to remove from office General Manuel Noriega of Panama. The aircraft's performance in placing ordnance onto specific targets with absolute precision was considered a vindication of the whole programme. Further action came in January 1991 with the Gulf conflict and a major proportion of the USAF fleet (42 out of the surviving 54) were eventually based in Saudi Arabia with 415th Tactical
Fighter Squadron 'Nightstalkers', the 416th TFS 'Ghostriders' and the 417th Tactical Fighter Training Squadron 'Bandits', all comprising the 37th Tactical Fighter Wing, one of whose aircraft dropped the very first bomb of Operation Desert Storm on 17 January 1991.
The result of a radical design philosophy which seeks to minimise the radar signature of an aircraft, the F-117A features angular multi-faceted air frame panels designed to deflect and in some cases absorb radar energy. The heavily-swept wing of just over 67° illustrates highly-complex aerodynamics and the intakes, doors and access panel shapes are all optimised to reflect radar signals. Wing and fuselage are aerodynamically blended and made of conventional aluminium but specially coated with radar absorbent materials. Tail surfaces, or 'ruddervators', are made of composites, and the whole aircraft is controlled by a quadruplex fly-by-wire system. The comprehensive avionics fit includes forward- and downward-looking infra-red
systems; head-up and head-down dis
plays; a retractable laser designator;
multi-function CRTs; a mission compu
ter and flight control comouter/naviga-
tion system interface, plus a global posi
tioning system. Powerplants are
non-afterburning variants of the General
Electric F404 engine used in the F-18
Hornet.
