Following the decision to produce a commercial helicopter, Fairey undertook the construction of a "Proof of concept" prototype. The Fairey Gyrodyne FB 1.
This aircraft had the functional performance of a conventional helicopter at low speeds and in the hover, but with the rotor being driven at low torque by the engine and reduced pitch of the main rotor at higher speeds, performed in effect as a gyrocopter, allowing significantly higher speeds than those of same era helicopters. So successful was the prototype that it was chosen in preference to the Westland/Sikorsky Dragonfly and Bristol Sycamore by the British Army for deployment to Malaya. Power was derived from an Alvis Leonides radial engine, fed to both the main rotor and a single tractor propeller mounted at the end of a stub wing. During low speed flight and hovering this small propeller provided the anti-torque thrust needed to counter the main rotor, whilst at higher speeds it provided forward thrust. In 1948, Having achieved a Helicopter world speed record of 124 miles per hour (200 Km/H) the first prototype crashed after a main rotor failure, killing the pilot and observer. Due to delays caused by the crash, in locating and resolving the cause of the crash, the order for 6 Gyrodynes by the M. O. D. was cancelled.
The second prototype FB 1 was subsequently, considerably modified into the Jet Gyrodyne. Changes included replacing the three blade main rotor with a two blade rotor with jets burning a Fuel/air mixture mounted at the tips. The single propeller was replaced with two pusher props, mounted on the stub wings. All of these modifications were carried out in anticipation of the development of the Fairey Rotodyne. Specifically to ascertain the most effective control systems for the project and test the performance of the tip jets, particularly in relighting them for transition from autogyro to helicopter flight. This prototype was retired when the Rotodyne main rotor testing began and can still be seen at the Museum of Berkshire Aviation near Reading in the UK.
After extensive testing, a single demonstrator was built, capable of carrying 40 passengers the Rotodyne first flew in 1957, with the first transition to forward flight in April 1958. Powered by two Napier Eland turboprops mounted under short wings. The tip jets for the main rotors were fed from compressors mounted on the engines both engines in opposing pairs. This meant that if the aircraft suffered an engine failure, power was still available to the main rotor. In fact sufficient power was available, that the Rotodyne could maintain it's hover with one engine shut down and the rotor blades fed by that engine feathered. Also the aircraft could auto-rotate if needed to a safe landing if for some reason the tip jets could not be restarted. Being an autogyro, the aircraft benefited from being able to abort an auto-rotation landing and go around if needed, unlike a conventional helicopter. Over the course of four years the prototype achieved a world speed record of 190.9 mph over 100 km course and flew from London to Paris via Brussels in half the time of a conventional helicopter.
After 1962, being government property, the aircraft was scrapped and largely destroyed. In a somewhat fitting epitaph for the independent British Aircraft industry, all that remains is the main rotor support, one of the Napier Eland engines, a test rotor blade a few tip jets and a short section of the fuselage, preserved at the Helicopter museum at Yeovil bearing part of the name of a once great aircraft manufacturer Fairey.