The Transcendental Aircraft Corporation , a small company formed by former Piasecki workers in 1945 to investigate tilting rotor technology put the final touches to an aircraft designed and built by Mario A. Guerierri . This prototype, known as the Model 1G , was a single-seater convertible helicopter with two contra-rotating rotors located at the end of its wings. These three-bladed rotors act as normal helicopter rotors, but they can also be swivelled forward to become the traction airscrews of a typical aircraft, lift then being provided by the fixed wings.

Thanks to contacts signed with US Air Force in 1952 and 1953, the Transcendental Aircraft Corporation was able to solve a number of problems, and more particularly that of instability phenomena occuring when the rotors are swivelled forward.

Since a helicopter rotor behaves differently from a conventional airscrew, a compromise had to be worked out. The negine reduction has been replaced by a two-gear reduction box, at the exit of which a gearing system has been attached which enables the rotors to be put into auto-rotation. At the engine's maximum output of 3000 RPM the rotors rotate at 633 RPM as airscrew, and at 240 RPM as helicopter rotors.

Three concentric tubes start from the swivelling device, the first of which moves the rotor, the second controls cyclic variation and the third variation of collective pitch. The time needed to move from the helicopter to the aircraft position is roughly three minutes. In this change-over, the rotors swivel through an angle of 82 degrees.

The Model 1G flew for the first time as a helicpter in June 15, 1954 and as convertible in December 1954.
The unit flew over 100 flights and 20 hours before being lost in an accident on July 20, 1955 due to a rotor control mechanical failure

Engine: Lycoming O-290-A, 160 HP
Length: 7.93m
Width: 11.58m (rotor tip to rotor tip)
Height: 2.13m
Rotor diameter: 5.18m
Weight empty: 658 kg
Weight fully loaded: 794 kg
Max speed: 196 kph (as helicopter), 256 kph (as airplane)
Absolute ceiling: 1525 m (as airplane)
Range: 90 minutes
Number of seats: 1

Transcendental helicopter

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