Warplanes of the USA: Bell X-22A
Bell X-22A
(US Army Photo)
Bell X-22A V/STOL Research Airplane (Serial No. 151521), currently in the Niagara Aerospace Museum, Niagara Falls, New York, on loan from the National Museum of Naval Aviation.
The Bell X-22 is an American V/STOL X-plane with four tilting ducted fans. Takeoff was to selectively occur either with the propellers tilted vertically upwards, or on a short runway with the nacelles tilted forward at approximately 45°. Additionally, the X-22 was to provide more insight into the tactical application of vertical takeoff troop transporters such as the preceding Hiller X-18 and the X-22's successor, the Bell XV-15. Another program requirement was a true airspeed in level flight of at least 525 km/h (326 mph; 283 knots). (Wikipedia)
(US Army Photo)
Bell X-22A V/STOL Research Airplane (Serial No. 151521).
(US Army Photo)
Bell X-22A V/STOL Research Airplane (Serial No. 151521).
(US Army Photo)
Bell X-22A V/STOL Research Airplane (Serial No. 151521).
(US Army Photo)
Bell X-22A V/STOL Research Airplane (Serial No. 151521).
(US Army Photo)
Bell X-22A V/STOL Research Airplane (Serial No. 151520).
(US Army Photo)
Bell X-22A (Serial No. 151521).
The X-22A was the Navy contracted and managed portion of the Tri-Service Assault Transport Program. The Bell X-22A was 39 ft long, featured side-by-side pilot seats, and had a gross weight of 17,000, including six passengers or a 1,200 lb payload. It was powered by four 1,250 shp GE YT58-GE-8D turboshaft engines that were cross-linked and had 35% excess power in case one of the engines failed in hover. Span over the canard (including the 7 ft diameter three-bladed ducted propellers) was 23 ft; across the rear wingtip ducts it was 39 ft. The ducts rotated non-differentially from 0° to 95° and had spanwise elevons across the center of the duct. Differential propeller pitch and the elevons were used to control the X-22A in hover. In forward flight, the ducts provided a significant amount of the aerodynamic lift. The first aircraft was rolled out on 25 May 1965. It made its first hovering flight in March 1966, and was tested to transition angles of up to 30° at speeds of up to 100 kt. That August, the first prototype was lost in a hard landing after only three hours of flying time due to a hydraulic failure. The second prototype made its first flight in January 1967 and performed hundreds of complete transitions. It reached a maximum speed in forward flight of 315 mph, and had a range of 450 miles. In early 1968, the X-22A's variable stability and control system was demonstrated, which allowed for research into hover and transition flight characteristics of other possible V/STOL aircraft. On 30 July 1968, it set a record by hovering at an altitude of over 8,000 ft. Flying until 1980, it accrued about 200 hours in the air.
(US Army Photo)
Bell X-22A (Serial No. 151521).
(Bell Photo)
Bell X-22A.
(Bell Photo)
Bell X-22A.
(Bell Photo)
Bell X-22A.
The X-22 was an unorthodox but tidy design, made primarily of aircraft aluminum alloy, with a boxy fuselage and four tiltducts, two forward and two aft. The front tiltducts were mounted on "shoulders" extending from the fuselage, with the rear tiltducts mounted on the ends of short wings. All the ducts had a fixed horizontal airfoil attached to the rear, with the rear ducts also having fixed wingtip airfoil extensions. There was a tall tailfin, with powerplants consisting of two General Electric YT58-GE-8D turboshafts, with 930 kW (1,250 SHP) apiece, mounted inboard and in front of each wing, for a total of four engines. The fans were driven using an array of driveshafts that permitted the aircraft to keep on flying if one engine were lost. There was also a very little prop mounted on top of the tailfin, one might guess for pitch trimming. The X-22 had tricycle landing gear, the nose gear having twin wheels and retracting backward, the main gear having single wheels and tucking inward into sponsons. Along with two flight crew, with side-by-side seating, the X-22 could carry six passengers. (Tiltducts, Tiltrotors, and Tiltwings)
(Bell Photo)
Bell X-22A.
