Even though the Valiant was produced as an interim type, the British felt it essential to develop an alternative in case the Valiant proved a failure in its initial trials. Designed to Specification B.14/46, the Short SA.4 Sperrin was intended as an insurance, which conformed to a less demanding specification in terms of speed and altitude over the target.
The aeroplane was thoroughly conventional by the structural and aerodynamic concepts of the day, with straight flying surfaces whose wings were set in the shoulder position on a comparatively deep fuselage whose lower portions accommodated the large nay/attack radar (chin position) and internal bomb bay (central position). One unusual feature was the powerplant, whose four Rolls-Royce Avon turbojets were located in under-and-over pairs on the wings about two-fifths of the way between the fuselage and the wingtips.
Two prototypes were built, the first flying on 10 August 1951 and used to test new high-altitude radar navigation and bombing equipment that was to be incorporated in the V-bombers. The second aircraft, which flew in August 1952, was used to test aerodynamic bomb shapes in connection with the development of Britain’s first atomic bomb, the MC.Mk 1 ‘Blue Danube’.
Engines: 4 x 2944kg Rolls-Royce Avon RA.3 turbojet
Max take-off weight: 52200 kg / 115082 lb
Wingspan: 33.20 m / 109 ft 11 in
Length: 31.42 m / 103 ft 1 in
Height: 8.69 m / 29 ft 6 in
Max. speed: 913 km/h / 567 mph
Ceiling: 13725 m / 45050 ft
Range: 6050 km / 3759 miles
Crew: 5
All Aero 