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 1988, it accrued about 200 hours in the air.

A video of the aircraft in flight can be see on the VFS Helicopter History Facebook site.


Data on design, manufacture and status

Design authority: Bell Aerosytems Company

Primary manufacturer: Bell Aerosytems Company

Parent type: No type defined

Aircraft status: No longer flying


Primary flight and mechanical characteristics

VTOL type: Convertiplane

Compound type: N/A

Lift configuration: Multi-rotor (x4)

Dedicated control device: Other

Crew required: TBA

Crew seating: Side-by-side

Landing gear: Wheels (all retractable)

Layout and Dimensions

Data on aircraft size

Overall Dimensions
Overall Height:  
Overall Length:  
Overall Width:  
Airframe Dimensions
Airframe Length:  
Airframe Width:  
Airframe Height:  
Landing Gear Dimensions
Landing Gear Base:  
Landing Gear Track:  
Cabin Dimensions
Cabin Internal Height:  
Cabin Internal Length:  
Cabin Internal Width:  

Weights and Performance

Data on aircraft weight and flight characteristics

Max Gross Weight (ground):  
Max Gross Weight (airborne):  
Max Take-off Weight:  
Empty Weight:  
Useful Load:  
Empty Weight Fraction:  
Climb Performance
Max Rate of Climb:  
Hover Performance
Hover Ceiling IGE:  
Hover Ceiling OGE:  
Max Level Flight Speed:  
Never Exceed Speed:  
Service Ceiling:  
Range and Endurance
Max Range:  
Max Endurance:  

Engine Details

Aircraft powerplant (lift and/or propulsion)

Provided powerplant data is for uninstalled, sea level, static operations.

Number of engines: 4
Normal Ratings
Max continuous:  
Take-off / rated:  
OEI Ratings
OEI contingency:  
OEI continuous:  
OEI 30-second:  
OEI intermediate:  

Primary Lift Device

Data on primary lift devices such as main rotors

Main Rotor Characteristics
Direction of Rotation: Unknown
Hub Type:  
Main Rotor Blade Characteristics
Blade Construction:  
Blade Chord:  
Blade Tip Geometry:  
Blade Twist:  
Number of Blades:  
Main Rotor Derived Characteristics
Disc Area:  
Disc Loading:  
Main Rotor Blade Derived Characteristics
Blade area per blade:  
Tip Speed:  

Primary Control Device

Data on primary control devices such as tail rotors

Tail Rotor Characteristics
Configuration: Unknown
Direction of Rotation: Unknown
Tail Rotor Blade Characteristics
Number of Blades:  
Blade Construction: N/A
Blade Chord:  
Blade Twist:  
Tail Rotor Derived Characteristics
Disc Area:  
Tail Rotor Blade Derived Characteristics
Tip Speed:  
Blade Area (per blade):  

Related VFS Resources

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Related Public Resources

Resources related to the X-22A , provided by public sources across the internet.