One of the first adaptations of the Hart day bomber involved fairly minor changes to satisfy an Army cooperation requirement, with the RAF needing a replacement for Armstrong Whitworth Atlas and Westland Wapiti aircraft. For this role the Hart was provided with a message pick-up hook and other equipment changes.
About 652 Audax biplanes were ordered for the RAF, including those purchased by South Africa and those transferred to Malaya for the Straits Settlement Volunteer Air Force. Others were constructed for Persia (with Bristol Pegasus and Pratt & Whitney Hornet engines), Iraq, Canada, Singapore and Egypt. The Egyptian aircraft with Armstrong Whitworth Panther X engines and supplied to allow Egypt to share with Britain the defence of Egypt, the Sudan and the Canal zone under the terms of the Anglo-Egyptian Treaty.
RAF Audaxes entered service in 1932 and some based overseas were still flying in 1941-42. An Audax squadron was used as fighter cover at the Digboi air station in north east Assam, India in 1942. Most of the remaining Audaxes were operated during the early war years as Hotspur glider tugs and trainers, 18 having previously been converted into Hart Specials.
Engine: 1 x Rolls-Royce "Kestrel IIS", 385kW
Max take-off weight: 1987 kg / 4381 lb
Empty weight: 1336 kg / 2945 lb
Wingspan: 11.4 m / 37 ft 5 in
Length: 9.0 m / 29 ft 6 in
Height: 3.2 m / 10 ft 6 in
Wing area: 32.4 sq.m / 348.75 sq ft
Max. Speed: 274 km/h / 170 mph
Cruise speed: 240 km/h / 149 mph
Ceiling: 6400 m / 21000 ft
Range w/max.fuel: 600 km / 373 miles
Armament: 2-4 .303 MG (7,7mm) machine-guns, 250kg of bombs
Engine: Rolls Royce Kestrel II B, 523 hp
Length: 29.593 ft / 9.02 m
Height: 10.4 ft / 3.17 m
Wingspan: 37.238 ft / 11.35 m
Wing area: 348.000 sqft / 32.33 sqm
Max take off weight: 4385.7 lb / 1989.0 kg
Weight empty: 2939.3 lb / 1333.0 kg
Max. speed: 148 kts / 274 km/h
Service ceiling: 21506 ft / 6555 m
Wing load: 12.71 lb/sq.ft / 62.00 kg/sq.m
Endurance: 4 h
Armament: 2x .303 MG (7,7mm) machine-guns, 4x 9kg Bomb / 2x 51kg Cont.