Fairey Rotodyne was a British compound gyroplane that was designed in the '50s by Fairey Aviation. The aircraft was planned to be used in commercial and military acts. An experimental aircraft of the project achieved to fly with the highest speed of any other helicopter till then. Rotodyne featured a rotor that worked with the fuel and compressed air from two Napier Eland turboprops, in its two wings. The rotor was used in vertical landing and take-off, in hovering and at low-speed flights. In normal flights, the whole energy was going to the two propellers.
Only a prototype was built of the project. Even if Rotody were promising and had successfully passed tests, the program was canceled. Its cancelation happened as Rotodyne couldn't achieve any commercial sales. The reason? Most companies thought that rotors would cause an irritating sound to the passengers inside the aircraft! However, there were also political reasons behind its cancelation. We just need to mention that it was a government-funded project...