The Bristol Type 171 Sycamore holds the distinction of being the first British helicopter to receive a certificate of airworthiness, as well as the first British-designed helicopter to be introduced by and serve with the Royal Air Force. The project grew from the work of Austrian designer Raoul Hafner, whose innovations — including the use of cyclic pitch via a compact rotor head — were quite revolutionary and continue in use on modern helicopters today. On 25 July 1947, the first prototype, VL958, performed the type's maiden flight, powered by a 450-horsepower Pratt & Whitney Wasp Junior engine; the Alvis Leonides engine was later adopted as the standard powerplant for all subsequent production aircraft. In RAF service, the Sycamore proved the value of rotorcraft in traversing inhospitable terrain, making valuable contributions during the Malayan Emergency, the Cyprus Emergency, and the Aden Emergency. During the 1950s, Sycamore crews helped pioneer many of the helicopter techniques commonly used today in air-sea rescue and troop transport work. One visible feature of all modern helicopters was also developed on the Sycamore: the first few aircraft were built with the pilot in the left-hand seat, but this was subsequently moved to the right, which became the standard for all helicopters that followed. In every sense, the Sycamore was the seed from which British rotary aviation grew.