Royal Air Force, Hellenic Air Force, Hellenic Navy, Chinese Nationalist Air Force, Kwangsi Air Force, Royal Canadian Air Force.
The Armstrong Whitworth Atlas was a British single-engine biplane designed and built by Armstrong Whitworth Aircraft.
It served as an army co-operation aircraft for the Royal Air Force in the 1920s and 1930s.
It was the first purpose-designed aircraft of the army co-operation type to serve with the RAF.
The Armstrong Whitworth Atlas was designed by a team led by John Lloyd, chief designer of Armstrong Whitworth Aircraft, as a replacement for the DH.9A and Bristol Fighter as an army co-operation aircraft for the RAF, in parallel with the related aircraft, the Ajax and Aries.
The Atlas was intended to meet the requirements of Specification 20/25.
The prototype Atlas (G-EBLK) was built as a private venture, first flying on 10 May 1925.
It was delivered to the Aeroplane and Armament Experimental Establishment, Martlesham Heath, where it was evaluated against the Bristol Boarhound, de Havilland Hyena, Vickers Vespa, and Short Chamois.
It proved superior in performance and handling and was recommended for production.
While the performance was generally good, the prototype could not be side slipped steeply, and this resulted in a redesign where sweptback metal wings, with differing wing section, were fitted.
When tested again, the Atlas was found to have lost its good handling, having dangerous stall characteristics.
The Atlas had already been ordered for service, however, and suffered a number of accidents during take off and landing in the first few months of operation until modified with automatic slats and increased sweepback.
This cured the poor handling.
The production Atlas had a steel tube fuselage with fabric covering with single-bay swept metal wings.
It could be fitted with a hook under the fuselage to pick up messages and could carry a 460 lb (210 kg) bomb load under the wings.
Length: 28 ft 6 1⁄2 in (8.700 m)
Wingspan: 39 ft 6 1⁄2 in (12.052 m)
Height: 10 ft 6 in (3.20 m)
Wing area: 391 sq ft (36.3 m2)
Airfoil: RAF 28
Empty weight: 2,550 lb (1,157 kg)
Max take off weight: 4,020 lb (1,823 kg)
Power plant: 1 × Armstrong Siddeley Jaguar IVC 14-cylinder two-row air-cooled radial engine, 450 hp (340 kW)
Maximum speed: 142 mph (229 km/h, 123 kn) at sea level, 134 mph (216 km/h; 116 kn) at 10,000 ft (3,000 m)
Range: 400 mi (640 km, 350 nmi)
Endurance: 3 hr 25 min
Service ceiling: 16,800 ft (5,100 m)
Time to altitude: 5 min 30 to 5,000 ft (1,500 m)
Guns: 1 × forward firing .303 in (7.7 mm) Vickers machine gun and 1 × .303 in (7.7 mm) Lewis Gun on Scarff ring in rear cockpit
Bombs: Up to 4 × 112 lb (51 kg) bombs under wings
Armstrong Whitworth Aircraft since 1913-Oliver Tapper.
Jane’s Encyclopedia of Aviation-Michael J. H Taylor.