The Vickers Vanncock was designed to meet the Air Ministry Specification B.19/27 calling for a long-range night bomber.
Only one prototype was built, J9131, but it was twice modified and given new type numbers.
The Vanncock Mk.I, Type 150, was powered by two Rolls-Royce Kestrels and fitted with single-bay outer wings.
The Vanncock Mk.II, Type 195, was re-engined with two Bristol Pegasus I,M.3s and had a three-bay wing. The four-seat Mk.II had an AUW of 16,000 lb, span of 76 ft 6 in, and length of 60 ft 4 in.
The final Type 255 reverted to two-bay wings of increased area, retaining the Pegasus engines.
All Aero 