In the same year as the Italian Forlanini, Gastel used a compressed air engine to power two pairs of rotors, each with a diameter of 1.7 metres. The engine, incidentally, was fed by means of a flexible tube from a compressor on the ground. The air-craft's total weight was just over 22kg.

The device made a successful take-off, but crashed into a wall, which unlucky accident put an end to its career. Castel later had the idea of replacing his compressed air engine by a petroleum engine.

P.Lambermont "Helicopters and Autogyros of the World", 1958