SEPTEMBER 06, 1996

SECTION:

AIRCRAFT - FIXED-WING - MILITARY

UNITED STATES OF AMERICA

LOCKHEED MARTIN AERONAUTICS SECTOR (LMAS)

TITLE:

LOCKHEED MARTIN (LOCKHEED) F-117A NIGHTHAWK

Precision attack fighter with stealth elements, optimised for radar energy dispersion and low IR emission.

Development began with USAF Flight Dynamics Laboratory contract to Lockheed Advanced Development Projects (Skunk Works), funded by DARPA under Have Blue programme; two XST (Experimental Stealth Technology) demonstrators produced, each powered by two 11.12 to 12.46 kN (2,500 to 2,800 lb st) GE J85-4As; first flight December 1977 by William C. Park; first prototype crashed 4 May 1978; second XST crashed at Tonopah Test Range 11 July 1979; similar to F-117 apart from inward-canted ruddervators. Span 6.71 m (22 ft 6 in), length 11.58 m (47 ft 3 in), maximum T-O weight 5,443 kg (12,000 lb), leading-edge sweep 72ø 30', four-transparency canopy.

Development and manufacture of operational F-117A started November 1978 under Senior Trend programme. First of five preseries aircraft (Article numbers 780 to 784) flew 18 June 1981. Planned production of 100 reduced to 59 (Article numbers 785-843); aircraft 785 crashed on first flight 20 April 1982; first hand-over to USAF (Article 786) 23 August 1982; funding 13 in FY80 and 11, 10, 11 and 14 in FY82-85; first picture and designation released 10 November 1988; first operational deployment in Operation Just Cause over Panama, 20 December 1989, when two F-117As each dropped a 907 kg (2,000 lb) laser-guided bomb on barracks area at Rio Hato; all 42 in-service F-117As participated in 1991 Gulf War against Iraq, flying some 1,270 missions.

VARIANTS:

A/F-117X: Proposed private venture long-range strike/attack aircraft adaptation of F-117A. Originally under designation F-117N Seahawk.

F-117A: As described.

F-117A +: Proposed modification of existing F-117A aircraft, utilising latest technology; Lockheed Martin quoting programme development cost of $79 million, covering operational prototype and including detail design, tooling, modification of test aircraft, manufacture of full-size pole model, ground and flight trials plus full-scale development of 18 advanced low-observable technologies. Company claims result to be vastly enhanced stealth fighter with greatly improved survivability prospects in high-threat environment.

F-117B: Skunk Works proposal for new-build programme taking advantage of commonality with A/F-117X naval version. Features redesigned wing and horizontal tail surfaces of A/F-117X and GE F414 afterburning turbofan engines; plus all-weather sensors, advanced signature reduction and improved aerodynamic qualities. Maximum gross take-off weight 33,203 kg (73,200 lb); internal payload 4,536 kg (10,000 lb); combat radius 980 n miles (1,815 km; 1,127 miles). Current Lockheed Martin sales effort envisages joint Air Force/Navy programme to capitalise on modular production methods and economies of scale.

F-117N: Original designation for proposed A/F-117X long-range strike/attack aircraft.

MODERNISATION:

Lockheed: The first phase of weapon system improvement began with Weapon System Computational Subsystem (WSCS) on 1 April 1984. First flight of aircraft modified under WSCS occurred on 2 October 1986 and fleet modification was completed on 21 January 1992. The modification involved replacement of Delco M362F computers by IBM AP-102. The next major weapon system improvement was the Offensive Capability Improvement Program (OCIP) which began on 1 December 1988; first `production' redelivery (805) 21 November 1990; programme completed 8 March 1995; improvements installed include a `four-dimensional' flight management system (time on waypoint +-1 second), new cockpit instrumentation with full colour Honeywell MFDs, digital moving map, digital situation displays, auto throttle and pilot-activated recovery system. Third phase first flight tested on 14 August 1992, involved new turret-mounted Infra-Red Acquisition and Designation Sensor (IRADS) by TI. First flight of Ring Laser Gyro Navigation Improvement Program (RNIP) occurred on 12 December 1994 and consists of a Honeywell ring laser gyro INS and Collins GPS. Achieved 50,000 flying hours in January 1991 and 100,000 hours in December 1994.

Lockheed Martin: Commenced conducting a USAF funded Mid-Life Improvement Study (MIPS) in early 1995 to analyse weapons, signature reduction and other upgrades. Work could begin in early 1996 with existing funding. Possible improvements include the installation of a MIL-STD-1760 databus which would allow the F-117A to launch GPS-guided weapons such as Joint Direct Attack Munition (JDAM) and Joint Stand-Off Weapon (JSOW) which are both under development. Other possibilities include a bubble canopy.

Loral: Awarded contract by Lockheed Martin to upgrade the Loral AP-102A computers in the Lockheed Martin F-117A aircraft. Upgrade could be worth US$10 million. Purpose of upgrade is to enhance computer memory and performance, reduce weight and power as well as improve reliability and maintainability.

OPERATORS:

Versions of the F-117 are in service with the US armed forces (58).

CUSTOMERS:

USAF; five preseries plus 59 production; deliveries seven, eight, eight, eight, eight, seven, five, four and three in the calendar years 1982 to 1990 (final delivery, of 88-0843, 12 July 1990).

First F-117A unit, 4450th Tactical Group at Tonopah (122 n miles; 225 km; 140 miles north-west of Las Vegas), Nevada, formed 15 October 1979 and equipped with 18 A-7D Corsair IIs until first F-117A arrived; P-Unit (later 4451st Test Squadron) formed June 1981; Q-Unit (later 4452nd TS) began operations 15 October 1982, flying first 4450th TG training operation (00786); Group transferred from direct control of Tactical Air Command to Tactical Fighter Weapons Center at Nellis AFB 1985; Z-Unit (later 4453rd Test and Evaluation Squadron) formed 1 October 1985; first of several public air display appearances made April 1990; unit renamed 37th Tactical Fighter Wing of 12th Air Force 5 October 1989; strength 40 F-117As divided between 415th and 416th TFS; A-7Ds replaced in training and chase duty by eight T/AT-38 Talons of 417th TFTS, also with balance of 16 remaining F-117As; first assignment away from Tonopah was covert deployment to UK AFB 18 June 1990; wing and squadrons deleted `Tactical' prefix 1 November 1991; transfer to Holloman AFB, New Mexico, began with delivery of 00791 for maintenance familiarisation, 7 January 1992; movement of remaining aircraft began 9 May 1992, when unit became 49th Fighter Wing (7th, 8th and 9th Fighter Squadrons).

US$6,560 million programme (1990), including US$2,000 million R&D, US$4,270 million for procurement and US$295.4 million for infrastructure. Average unit cost US$42.6 million (then-year dollars).

Multifaceted airframe designed to reflect radar energy away from originating transmitter, particularly downward-looking AEW aircraft; vortexes from many sharp edges, including leading-edge of wing, designed to form co-ordinated lifting air flow pattern; wings have 67ø 30' sweepback, much greater than needed for subsonic performances, with aerofoil formed by two flat planes underneath and three on upper surface; forward underwing surface blends with forward fuselage; most door and access panels have serrated edges to suppress radar reflection; internal weapon bay 4.7 m (15 ft 3 in) long and 1.75 m (5 ft 9 in) wide divided longitudinally by two lengthwise doors hinged on centreline; boom refuelling receptacle on port side of top plate, aft of cockpit. Frontal radar cross-section estimated as 0.01 m{2} (0.1 sq ft).

Four omnidirectional air probes at nose indicate GEC Astronics quadruplex fly-by-wire control system, similar to that of F-16, using two-section elevons and all-moving ruddervators together for control and stability; ruddervators swept about 65ø and set at 80øto each other.

Material principally aluminium; two-spar wings; fuselage has flat facets mounted on skeletal subframe, jointed without contour blending; surfaces coated with various radar-absorbent materials. Ruddervators being replaced by new units of thermoplastic graphite composites construction, removing previous speed restriction due to flutter. Fleet modification was completed 11 August 1994.

Tricycle type by Menasco, with single wheels all retracting forward. Loral brakes and wheels; Goodyear tyres. All doors have serrated edges to suppress radar reflections. Emergency arrestor hook with explosively jettisoned cover.

Two 48.0 kN (10,800 lb st) class General Electric F404-GE-F1D2 non-augmented turbofans. Rectangular overwing air intakes with 2.5 x 1.5 cm (1 x {5/8} in) for anti-icing and low observability. Auxiliary air intake doors in horizontal surface immediately to the rear. Part of cold air ingested bypasses engine and is mixed with exhaust gases for cooling. Narrow-slot `platypus' exhausts in rear fuselage, 1.65 m (5 ft 5 in) long and 0.10 m (4 in) high, with extended lower lip, surrounded by heat tiles of type used on Space Shuttle and with 11 vertical, internal guide vanes. Sundstrand air turbine starter. In-flight refuelling receptacle in decking aft of cockpit, illuminated for night refuelling by lamp at apex of cockpit.

Pilot only; McDonnell Douglas ACES II zero/zero ejection seat. Five individually framed flat-plate windows, including single-piece windscreen. Transparencies, gold-coated for radar dissipation, produced by Serracin/Sylmar Corporation. Canopy hinged to open upward and backward.

AlliedSignal environmental control, auxiliary power and emergency power systems.

AVIONICS:

Forward-Looking Infra-Red (FLIR) sensor, with dual fields of view, in recessed emplacement, covered by fine mesh screen, below windscreen. Downward-looking DLIR and laser designator beneath forward fuselage to starboard of nosewheel bay; FLIR and DLIR by Texas Instruments (to be replaced by improved equipment during third-phase retrofit in 1994). HUD based on Kaiser AN/AVQ-28; large head-down display for FLIR imagery flanked by two multifunction CRTs. Retractable radio antennae beneath fuselage, ahead of port main landing gear, and on spine. Honeywell radar altimeter, Honeywell SPN-GEANS INS (replaced by Honeywell H-423/E ring laser gyro from August 1991; Rockwell Collins GPS to be added); IBM AP-102 mission computer (replacing original three Delco M362F computers); GEC-Marconi flight control computer/Navigation Interface and Autopilot Computer (NIAC) system; SLI Avionic Systems Corporation expanded data transfer system and AHRS. Harris Corporation digital moving map added as retrofit with full-colour MFDS.

`Full range of USAF tactical fighter ordnance', principally two 907 kg (2,000 lb) bombs: BLU-109B low-level laser-guided or GBU-10/GBU-27 laser-guided glide weapons; alternatively, AGM-65 Maverick or AGM-88 HARM ASMs. Internal carriage on two extendible beams in weapon bay. (Only missiles with seeker heads extended below aircraft prior to launch; bombs released from within weapon bay.)

EXTERNAL:

Wing span 13.20 m (43 ft 4 in)

Length overall 20.08 m (65 ft 11 in)

Height overall 3.78 m (12 ft 5 in)

(estimated):

Wing area 105.9 m{2} (1,140 sq ft)

WEIGHTS:

AND LOADINGS:

Weight empty (estimated) 13,608 kg (30,000 lb)

Max T-O weight 23,814 kg (52,500 lb)

Max level speed Mach 1+*

Normal max operating speed Mach 0.9

T-O speed at normal combat weight 165 kts (306 km/h; 190 mph)*

Landing speed 150 kts (227 km/h; 172 mph)*

g limit +6

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