As proposed, the aircraft was an all-metal, twin-engine high-wing monoplane based on the pre-war Bristol Bombay, having wings of the same section and taper but with a swept leading edge and straight trailing edge with two spars in place of the seven used in the Bombay. The square-section fuselage was clear of internal obstructions; in the original design this was to be loaded via a trapdoor in the nose, but the Air Ministry requirements necessitated a change to clamshell doors in the nose. Considerable effort was made to maximise the usable internal volume of the aircraft in order to readily accommodate the carriage of bulky cargoes. The flight deck was elevated above the load space on the nose as to not obstruct access; the crew would enter the flight deck via a fixed vertical ladder on the side of the cargo bay. Power was to have been provided by a pair of a development of the Bristol Perseus using nine Bristol Centaurus cylinders, each engine rated at .