Lockheed AH-56A Cheyenne
In March 1966 Lockheed began development of an advanced armed helicopter, designated as the AH-56A Cheyenne. Known as a compound helicopter, being provided with small low-set cantilever wings to off-load the main rotor in high-speed flight, it was designed to have a maximum level speed 244 mph (393 km/h). Army support came to an end in 1969, and economic considerations eventually caused Lockheed to end its development programme.
Engines: 1 x General Electric T64-GE-16, 3925 shp.
Rotor dia: 51 ft 3 in (15.62 m).
Length: 60 ft 1 in (18.31 m).
Height: 13 ft 8.5 in (4.18 m).
Max TO wt: 18,300 lb (8300 kg).
Max level speed: 244 mph (393 kph).
Range: 1,225 miles.
Ceiling: 20,000 ft.