Beating Gravity - Bell X-22A

The X-22A joint-service research design was sponsored by the US Navy to investigate the feasibility of an arrangement of four tilting duct power plants for VTOL aircraft. It was developed as the D2127 light transport and ordered in November 1964.

The four engines were located in pairs, on each side of the forward fuselage and on the leading edge of the tail-mounted wing. The ducts could tilt through 90° for transition between vertical and horizontal flight. Control was achieved by modulation of each duct's thrust through propellor pitch change, and by an elevon located in the slipstream of each duct.

The X-22A first flew in March 1968, and was an acceptable aircraft, but the first example was lost in an accident that August. The second, improved machine was quite a success when fitted, in spring 1968, with the Cornell Aeronautical Laboratory's variable stability system. When the US services completed their evaluation, the X-22A was handed to Cornell for further research.

Bell X-22A data:
POWERPLANT: Four General Electric YT58-GE-8D ducted turboshafts, of 1,250 shp (932 kW) each. MAX. TAKEOFF WEIGHT: 16,755 lb (7800 kg) PAYLOAD: Passengers or 1,200 lb (544 kg) of freight. SPAN: 23 ft 0 in (7.01 m) across front ducts, 39 ft 3 in (11.96 m) across rear ducts. LENGTH: 39 ft 6 in (12.04 m)	INTERNAL DUCT DIAM.: 7 ft 0 in (2.13 m) MAXIMUM SPEED: 255 mph at optimum altitude OPERATIONAL RANGE: 445 miles SCHEMATIC DIAGRAM:

More X-22 links:

http://avia.russian.ee/vertigo/bell_x-22-r.html