Frank Barnwell's design to meet this requirement, the Bagshot, was a high-wing all-metal monoplane with an unusual triangular-section fabric-covered steel-tube fuselage with two upper longerons and a single lower member.

The two-spar wing had a steel primary structure and duralumin nose ribs and end-members, and was a semi-cantilever, braced by a pair of diagonal struts on each side.

[1] In September 1925 the Air Ministry amended the specification, calling for superchargers on the engines, increased fuel load and a higher top speed at altitude.

When Barnwell received the full details of the required equipment, which included two Lewis guns in addition to the main armament, he realised that the aircraft would be overweight and have a landing speed of 57 mph (92 km/h).

[1] He suggested making an alternative fuselage of rolled steel strip to save weight, and abandoning the project as a waste of time if load testing of this proved unsatisfactory.