Design Features
The unique design of the single-seat F-117A provides exceptional combat capabilities. About the size of an F-15 Eagle, the aircraft has a conventional aluminum, titanium and stainless steel rib and stringer semi-monoque structure. Externally, this unique aircraft is composed of numerous facets to direct radar energy away from the emitter, much like the design of the Hopeless Diamond model Have Blue vehicle. In order to lower its Radar Cross Section (RCS), leading and trailing edges are composed of non-metallic honeycomb structures and the entire aircraft is covered with a thin layer of Radar Absorbent Material (RAM). The “V” shaped twin tails are graphite thermoplastic composite structures. All openings in the aircraft (engine inlets, vents, etc.) are covered with grids or screens to reduce radar reflection.
In order to reduce cost and speed development of the F-117, off-the-shelf hardware was used some cases. Two 13,000 lb. thrust class General Electric F404 non-afterburning turbofan engines derived from the Navy F-18 power the aircraft. The aircraft is also equipped with an F-18 derived Auxiliary Power Unit (APU) to permit self starting of the main engines and provide backup electric and hydraulic power. Its quadruple redundant fly-by-wire flight control system, critical to flight of this inherently unstable aircraft, is derived from the F-16. Three International Business Machines (IBM) mission computers, derived from those used on the Space Shuttle, drive the complete avionics suite.
Modern digital avionics is the heart of this precision bombing platform, increasing mission effectiveness and decreasing pilot workload. The F-117 cockpit is equipped with Heads up display (HUD), twin color multifunction display indicators, and a digital moving map system. Navigation duties are handled by a state-of-the art Ring Laser Gyro (RLG) and Global Positioning System (GPS). To perform its night bombing mission, the Black Jet utilizes an Infra Red Acquisition and Designation System (IRADS) with forward and down looking capability. The laser targeting function of the IRADS guides the array of precision laser guided munitions carried by the F-117 with deadly accuracy. Although this aircraft can employ a variety of tactical and precision munitions, the weapon of choice is the laser guided GBU-27, a 2000 lb. penetrator with a hardened steel case, developed specifically for the F-117. With its ability to penetrate over 6 feet of reinforced concrete, destruction of command and control bunkers and hardened aircraft shelters is standard duty for the Black Jet.