The Gloster Aircraft Company AS31 was a large, twin-engine, two bay biplane of all-metal construction with relatively high-power to secure good performance in tropical conditions. As a result, it could maintain flight on one engine if needed, at maximum weight and at 9,000 ft altitude.
The company advertised it stating ‘The Gloster Aircraft Co. Ltd are specialising in civil aircraft - Survey, Passenger Carrying, Freight Carrying and Postal Machines’.
The design of the Gloster AS31 had its origins within the De Havilland Aircraft Co Ltd as the DH67, the intended customer being the Aircraft Operating Co. Ltd (a sister firm of De Havilland), as a replacement for their aging DH9's.
The DH67 in turn, was in effect a scaled down all-metal, twin-engine version of their DH66 Hercules.
The huge success of the DH Moth and production of the DH66 had resulted in a management decision, taken in November 1928, to transfer responsibility for the design to the Gloster Aircraft Co Ltd.
Gloster initially modified the DH67 aircraft, to make it more suitable for a greater multi-role use, rather than as a dedicated survey machine. The also gave it the designation AS.31 (Aerial Survey 31) and in its final form, it bore only a superficial resemblance to the original DH design.
Two airframes were built, the first aircraft (G-AADO) flying for the first time in June 1929. It was eventually handed over to the Aircraft Operating Company on 25th January 1930, whereafter it was occasionally chartered by the Secretary for Air for various overseas visits.
The second machine (K2602) was delivered to the RAF and was allocated to Royal Aircraft Establishment (RAE) Farnborough for trials. Being delivered on 16th November 1931, it was mainly used for radio telegraphy trials.
In March 1930, the prototype (G-AADO) was subsequently flown by De Havilland Chairman Alan S Butler from Heston to Cape Town between 20th March and 11th April 1930, achieving an average of 128 mph.
It was later used for survey work in Bulawayo during 1931, completing a survey of 63,000 square miles of Northern Rhodesia. In these operations, the aircraft demonstrated outstanding reliability before it was transferred to the South African Air Force in 1935, It remained in service until it was scrapped in December 1942.
Gloster Aircraft received interest from Egypt, who explored its potential for a bomber / reconnaissance role, although this was later abandoned.
|Powerplant||Two 525 hp Bristol Jupiter XI radial engines|
|Span||61 ft 0 in|
|Maximum Weight||8,570 lb|
|Capacity||Two or three seat – pilot, navigator and camera operator|
|Maximum Speed||131 mph|
|Cruising Speed||110 mph|
|Range / Endurance||495 miles, 4.5 hr at 1,000 ft; 6.5 hr at 20,000 ft|
Two aircraft ony, G-AADO and K2602, neither of which survive.