Bristol Sycamore
The Bristol Sycamore, the Bristol Aeroplane Company's Type 171, was the first British-designed helicopter to fly and the first British helicopter to receive a certificate of airworthiness. Designed under Raoul Hafner by the company's new Helicopter Department, the single-engined type first flew in July 1947 and entered RAF service in 1953, equipping nine squadrons mainly on search and rescue, casualty evacuation and training work, including operations in the Malayan Emergency. About 180 were built by 1959 and sold to Australia, Belgium and Germany as well as to civil operators; the RAF retired its last in 1972, and survivors are preserved in museums in Britain and Australia, with one still flying in Austria.
Why It Mattered
The RAF Museum calls the Sycamore the first British-designed helicopter to fly. In April 1949 it became the first British helicopter to receive a certificate of airworthiness. Museums Victoria judges it the first commercially successful British helicopter design. During the 1950s its crews helped pioneer the air-sea rescue and troop transport techniques that helicopter forces still use today. Together with the Westland Dragonfly, it proved the importance of helicopters for carrying troops and supplies into terrain that fixed-wing aircraft and road vehicles could not reach.
Design Notes
The Sycamore grew out of wartime rotorcraft work at the Airborne Forces Experimental Establishment, whose helicopter designers were released to the Bristol Aeroplane Company, which set up a Helicopter Department around them. The department's head was Raoul Hafner, the helicopter pioneer whose own company Bristol had acquired. Its first prototype, VL958, flew in July 1947 with a 450-horsepower Pratt & Whitney Wasp Junior, because Bristol's own range had no suitable engine. Production aircraft standardised on a single Alvis Leonides piston engine of 550 hp, driving a three-bladed main rotor whose blades were made of wood. The cabin seated four or five occupants, and each airframe was fitted for quick conversion between six major roles, among them search and rescue, air ambulance and dual instruction. The air ambulance version was unusual for its time in carrying up to two patients inside the cabin on stretchers stacked one above the other, rather than in the external pods then usual. On the main production Mk.4 the pilot's seat moved to the right, following American practice, an arrangement the Dumfries museum notes later became standard for helicopters.
Operational History
The Sycamore entered RAF service in April 1953, when the HR.14 joined No. 275 Squadron. In 1953 No. 275 Squadron took up a new role as the RAF's first dedicated helicopter search and rescue unit in Great Britain. Nine RAF squadrons flew the type in all, in marks specialised by task: the HC.10 as an air ambulance, the HC.11 on Army communications work, and the HR.12, HR.13 and HR.14 on search and rescue. The RAF's Central Flying School also used the type to train pilots. In the Malayan Emergency it carried Army patrols into the jungle and evacuated casualties from small clearings, work the RAF Museum calls invaluable and a great morale booster. RAF Sycamores also served in the Cyprus and Aden emergencies, on rescue work, deploying small army patrols and spotting. Fifty Sycamores were delivered to the German Federal Government, and three were built for Belgium for use in the Belgian Congo. Australia's navy operated its HR50/51 Sycamores on training, communications and search and rescue work, among them flood rescue operations in New South Wales in 1955. The Royal Australian Air Force flew two Sycamores in support of the Woomera Rocket Range between 1951 and 1965. Civil machines were sold simply as the Bristol Type 171, and examples were used for joint evaluation by British European Airways alongside the RAF and the Army Air Corps. In Australian civil hands, Australian National Airways' 'Yarrana' was the first helicopter to cross Bass Strait and, in 1957, made what Museums Victoria records as the world's longest helicopter flight to that time, from Sydney to Western Australia.
Afterlife
Production ended in 1959, after approximately 180 Sycamores had been built in four main versions. The RAF officially retired the type in 1971, although the last two remained in service until August 1972. Survivors remain on display in several museums: the RAF Museum's collection includes the HR.14 XJ918. At Dumfries, the museum's Mark 3, WA576, a former trials aircraft delivered new to the Joint Experimental Helicopter Unit, is undergoing restoration; it arrived at the museum in 1987. In Australia, one of the two Woomera machines, A91-1, survives at the Moorabbin Air Museum in Melbourne. One Sycamore still flies: HR.52 OE-XSY in Austria, which the Flying Bulls reinstated in 2013.