Rockwell became responsible in 1972 for development of the US Navy's XFV-12A V/STOL Fighter/Attack Technology Prototype programme.
Basically a single-seat all-weather V/STOL fighter/ attack aircraft, the XFV-12A made use of an augmentor wing concept in which the efflux of its single Pratt & Whitney F401-PW-400 afterburning turbofan engine could be diverted to nozzles in the wings and foreplanes for V/STOL operations.
An ejector-flap system was incorporated in the design of each wing and foreplane, in which ambient air was mixed with turbine efflux in a ratio of 7:1 to provide the essential jet-lift for vertical operations and, when the flaps are raised or lowered progressively, for transition from vertical to horizontal flight and vice versa.
The main landing gear, canopy and other cockpit parts came from an A-4 Skyhawk. The main wing box and parts of the inlets were from an F-4 Phantom.
The XFV-12 did get off the ground - and was tested in a tethered mode, but the programme proved a disappointment and failed to provide an alternative to the Harrier.
Engine: 1 x 133.4kN Pratt & Whitney F401-PW-400 turbofan
Max take-off weight: 11000 kg / 24251 lb
Wingspan: 8.69 m / 29 ft 6 in
Length: 13.35 m / 44 ft 10 in
Height: 3.15 m / 10 ft 4 in