The Miles M.77 Sparrowjet was a twin-engined jet-powered racing aircraft built by the British aircraft manufacturer F.G. Miles Limited. It was a one-off conversion, involving the fitting of Turbomeca Palas turbojet engines to the prototype Miles Sparrowhawk, enabling the aircraft to achieve higher performance than could be achieved with its conventional piston engine arrangement.

The Sparrowhawk had been a racing aircraft developed and produced in small numbers by Miles Aircraft during the 1930s. During the late 1950s, the owner of one such aircraft, Fred Dunkerley, requested that Miles look into converting the type to use jet propulsion for greater performance. During December 1959, the company received the aircraft to perform the extensive modification programme; in addition to the installation of French Palas turbojets, the original piston engine was eliminated while the forward fuselage was entirely replaced and rebuilt with the cockpit in a more forward position. The conversion took almost three years to perform.

On 14 December 1953, the completed Sparrowjet conducted its maiden flight. While the aircraft proved to be capable of speeds in excess of 200 mph, it was noted to accelerate somewhat slowly. Its owner quickly put it to use as a somewhat unique racing aircraft for the era, a factor which likely aided the Sparrowjet in multiple victories, including the SBAC Challenge Cup on 21 May 1956, and the King's Cup Race on 13 July 1957, the latter in which the aircraft had reported attained a maximum speed of 228 mph (367 km/h). However, the Sparrowjet was heavily damaged by a hangar fire while being stored at RAF Upton during July 1964, ending its racing career.

Design and development

During the 1930s, the British aviation company Miles Aircraft produced half a dozen Miles Sparrowhawks, a piston-powered racing aircraft.

Extensive modifications were made to the airframe, including the replacement of the forward fuselage and tail.

The French Turbomeca Palas, a centrifugal flow turbojet engine, was selected, and in order to accommodate a pair of these within the wing root, the wing received additional modifications.

In December 1950, the Sparrowhawk arrived at Miles' Redhill facility to commence conversion but mid-way through the conversion in 1952, Miles relocated to Shoreham, with the Sparrowhawk relocated by road. The completed Sparrowjet made its first flight on 14 December 1953, when George Miles also made his first flight in a jet-powered aircraft. It was found that the aircraft's maximum speed was in excess of , although a poor rate of acceleration was also observed, a factor that has been attributed to the power output of the Palas engine being a somewhat modest per engine at sea level. Prior to the discovery of the fault, the occasion had been intended to be the Sparrowjet's racing debut; this would occur roughly two months later at the Southern Aero Club Invitation Race, which was also held at Shoreham.

For a time, the Sparrowjet was based at British European Airways's (BEA) main engineering base. During the early 1960s, it was transferred to RAF Upton in Wiltshire, England. The Sparrowjet was in storage at RAF Upton when it was severely damaged by a hangar fire in July 1964; at the time, it was only partially assembled, with items such as its engines having been removed.

Specifications

References

Citations

Bibliography

  • Amos, Peter. and Don Lambert Brown. Miles Aircraft Since 1925, Volume 1. London: Putnam Aeronautical, 2000. .
  • Berliner, Don. History's Most Important Racing Aircraft. Pen & Sword Books Limited, 2014. .
  • Brown, Don Lambert. Miles Aircraft Since 1925. London: Putnam & Company Ltd., 1970. .
  • Jackson, A.J. British Civil Aircraft 1919–1972: Volume III. London: Putnam, 1988. .
  • Temple, Julian C. Wings Over Woodley - The Story of Miles Aircraft and the Adwest Group. Bourne End, Bucks, UK: Aston Publications, 1987. .
  • Miles Aircraft