The
Bullfinch was designed by
Frank Barnwell, chief designer of the
Bristol Aeroplane Company, as a parasol-wing monoplane single-seat
fighter, which was convertible to a two-seat
biplane, thus meeting the requirements of the
Royal Air Force for both a single-seat
interceptor fighter and a two-seat
reconnaissance-fighter. The potential cost savings associated with this concept, which was planned to be powered by the
Jupiter engine, the rights to which Bristol had just acquired from the bankrupt
Cosmos Engineering, interested the
Air Ministry, who wrote a specification (
Specification 2/21) around Barnwell's proposed design, and ordered three prototypes in June 1921. The wing was wooden on the
prototypes, but was planned to be of metal construction for any subsequent production aircraft. To produce the two-seat fighter-reconnaissance version, the
Type 53 Bullfinch Mk II, an extra fuselage
bay was added aft of the pilot containing a
cockpit for the observer, and a cantilever bottom wing attached which compensated for the shift in
centre of gravity resulting from the weight of the observer and the lengthened fuselage. The first prototype, a Type 52 monoplane, flew on 6 November 1922, with the second prototype, also a monoplane, flying in May 1923. After first flying as a monoplane, the third prototype was converted to the biplane configuration, flying in that configuration on 17 March 1924. While the single-seater demonstrated reasonable performance, the two-seater was overweight, and proved incapable of carrying the required military load. No further production occurred. ==Variants==