Bell Model 65 ATV

Bell showed interest in VTOL aeroplanes as early as the early 1940s. In January 1941, a patent was taken for a single-engine VTOL tail-sitting fighter with contra-rotating propellers. These studies were followed in 1944 by the design of a twin-engined jet-propelled tail-sitting VTOL tactical aircraft (known as the Young's Convertiplane) which never left the drawing board because the available jet engines were not considered powerful enough.

Studies were taken further when, in 1950, the Bureau of Aeronautics sponsored a competition for a VTOL fighter. Unlike other aircraft manufacturers which proposed a tail-sitting machine (Lockheed XFV-1 and Convair XFY-1), the Bell design team thought that the future VTOL aircraft should remain in a conventional attitude. The XFV-l/XFY-1 programmes were eventually cancelled. In 1952, the Bell proposal for a jet-propelled VTOL fighter led to a feasibility study contract. But the Bell team decided to go beyond that and, as a private venture, initiated the building of a low-cost test vehicle to confirm the viability of their design. The ATV or Air Test Vehicle as it was known (Bell Model 65) was constructed at the lowest cost possible and had a rather weird appearance. The airframe was made of existing parts: wings from a Cessna 170, fuselage from a Schweizer glider and undercarriage from a Bell Model 47. Power came from two 450kg Fairchild J44 lightweight turbojets externally mounted on either side of the fuselage and from an auxiliary Turbomeca Palouste turbo-generator which was installed on the back of the fuselage between the two J44s. Its purpose was to deliver compressed air to the attitude control system. Compressed air was bled in piping through nozzles disposed at the wingtips and tail. Conversions to and from vertical flight were made by rotating the J44 engines 90 degrees.

The Model 65 was completed in eight months and, by December 1953, was ready for flight. The first hover flight was made in January 1954 with Dawe Howe at the controls. Unfortunately, a month later, a compressor disc in the starboard engine failed and damaged the fuel lines causing a fire. Dawe Howe escaped uninjured but the machine suffered extensive damage. It was repaired and resumed test flights. The flight-test programme was terminated in the spring of 1955 by which time the ATV had logged 4.5 hours. These comprised only hovering and conventional flights as the ATV never completed any transition from vertical to horizontal flight.

The ATV has survived and is held by the National Air and Space Museum.

Alain J Pelletier "Bell Aircraft since 1935", 1992