The full-size wooden mockup at Willesden during the winter of 1936-37.

Simplicity of Construction No. 1 THE BRITISH BURNELLI FUSELAGE IS A STRAIGHTFORWARD STRUCTURE AND COMPRISES:- Two flat side panels - large sheets forming upper and lower surfaces - four simple rectangular bulkheads. These four bulkheads, in addition to forming the fuselage structure, are employed as supporting structure for engines, wings, and landing gear. Such a combination into one simple structure of several functions is exclusive to the Burnelli and accounts for the speed of construction and consequent low production costs.
The full-size wooden mockup at Willesden during the winter of 1936-37. Note the painted Rolls-Royce Kestrels.

The OA-1 shortly after roll-out, in bare metal finish before painting. It made its first flight, from Eastleigh, on January 12, 1939.

Cunliffe-Owen O.A.1 (UK) Improved version of the Burnelli UB-14 airliner, built during 1937-38 and powered by two Bristol Perseus XIV engines. One operated by the French in Africa.

The nacelles of the Bristol Perseus XIVC sleeve-valve engines are located at the front corners of the central wing portion or fuselage.

The camouflaged OA-1, still in its civil marks, landing in French Equatorial Africa in June 1941.