The Armstrong Whitworth AW.15 Atalanta was a four-engine airliner designed and produced by the British aircraft manufacturer Sir W.G. Armstrong Whitworth Aircraft Limited at Coventry.
The Atalanta was specifically developed to fulfill the needs of the British airline Imperial Airways, who sought a new four-engined airliner to serve its African routes.
A monoplane configuration was adopted largely due to its low drag qualities, which led to a substantially different configuration to that of the preceding Armstrong Whitworth Argosy airliner.
Upon its review of Armstrong Whitworth’s proposal, Imperial Airways opted to order it into production before a prototype had even been assembled, much less flown.
On 6 June 1932, the prototype, G-ABPI, performed its maiden flight; it was named Atalanta, which was later applied to the whole class as well.
Flying testing revealed only minor difficulties, many of which were rapidly resolved, enabling the aircraft to receive a certificate of airworthiness only three months later.
On 26 September 1932, Imperial Airways operated the type’s first commercial service from Croydon to Brussels and Cologne.
The Atalanta primarily served the airline’s Eastern routes as intended for five years before being displaced; in its later year, various other civil and military operators flew the type up until its withdrawal amid the Second World War.
Shortly after the conflict’s start, the remaining five Atalantas were initially taken over by British Overseas Airways Corporation (BOAC).
During March 1941, they were impressed into use by the Royal Air Force (RAF) in India, where they were used to ferry reinforcements to Iraq in response to the Rashid Ali uprising.
During December 1941, shortly following Japan’s entry into the war, the fleet was handed over to the Indian Air Force for use on coastal reconnaissance duties, armed with a single .303 in (7.7 mm) machine gun operated by the navigator.
The final patrol by the type was flown on 30 August 1942, while the two survivors were transferred to transport duties where they continued in use until June 1944.
Capacity: 9–17 passengers
Length: 71 ft 6 in (21.79 m)
Wingspan: 90 ft 0 in (27.43 m)
Height: 14 ft 0 in (4.27 m)
Wing area: 1,285 sq ft (119.4 m2)
Empty weight: 14,832 lb (6,728 kg)
Max take off weight: 21,000 lb (9,525 kg)
Power plant: 4 × Armstrong Siddeley Serval III ten-cylinder two-row air-cooled radial engine, 340 hp (250 kW) each
Maximum speed: 156 mph (251 km/h, 136 kn) at 3,000 ft (910 m)
Cruise speed: 118 mph (190 km/h, 103 kn) at 9,000 ft (2,700 m)
Stall speed: 51 mph (82 km/h, 44 kn)
Range: 640 mi (1,030 km, 560 nmi)
Service ceiling: 14,200 ft (4,300 m)
Rate of climb: 700 ft/min (3.6 m/s)
Time to altitude: 21.5 min to 9,000 ft (2,700 m)
Armstrong Whitworth Aircraft since 1913-Oliver Tapper.
Jane’s Encyclopedia of Aviation-Michael J. H Taylor.