The Rotodyne was an experimental vertical take-off and landing transport using the principle
of a powered rotor for VTOL capability, combined with conventional forward propulsion and a
fixed wing to off-load the rotor and make possible higher cruising speed. Fairey Aviation
used for the development of the Rotodyne the experience gained from the Gyrodyne of the
Technically a compound helicopter rather than a true convertiplane the Rotodyne was intended
as a medium-haul "flying bus". With a crew of two and forty passengers it would be capable of
flying economical payload between city centers. The sole prototype Rotodyne Y, powered by two
2,800 hp engines mounted under wings, flew for the first time from White Waltham on November 6, 1957.
For take-off, the engines were coupled to auxiliary air compressors through a clutch,
supplying compressed air to the rotor, where it was ignited with kerosene in Fairey-developed
pressure-jets at the blade-tips. After take-off, transition to forward flight was
accomplished by progressively transferring power from the rotor to the two conventional
propellers. In normal flight the air compressors were "declutched" and all power went into
the propellers, the rotor then "free-wheeling" as on an autogiro.
The first transition from vertical to level flight was made on April 10, 1958, after which the
procedure became routine during tests. On January 5, 1959 the Rotodyne set a rotary-winged
world speed record at 190.9 mph (307 kmh) over a 62 mls (100 km) closed circuit. Also in 1959 the aircraft was
modified to increase the wing angle of incidence and to introduce ailerons. A third vertical
fin centered on the tail had been added for increased performance at higher speeds. Further
changes include rotor head fairings and shortening of jet outflux pipes outboard of engine
A larger version, the Rotodyne Z, was offered carrying up to 70 passengers and powered by
5,250 hp Rolls-Royce Tyne engines by the time Fairey Aviation helicopter interests were
acquired by Westland in 1960. The program was continued but due to lack of government support
it came to a halt in early 1962.