The AW.15 Atalanta was designed to meet a 1930 Imperial Airways requirement for an airliner for its African lines, in particular for the service between Kisumu in Kenya and Cape Town, South Africa. The specification called for an airliner that could carry nine passengers, three crew and a load of freight for 400 miles (640 km), cruising at 115 mph (185 km/h) at 9,000 ft (2,740 metres). As Imperial Airways had decided to standardise on four-engined aircraft to prevent the failure of a single engine causing forced landings, the specification required four engines. The prototype, G-ABPI, was named Atalanta and first flew on 6 June 1932, flown by Alan Campbell-Orde.
The Atalanta was a high-wing monoplane with four 340 hp (250 kW) Armstrong Siddeley Serval III ten-cylinder radial engines. Its composite construction included steel, plywood and fabric; the undercarriage was fixed but was streamlined to minimize drag. The overall design of the aircraft was rather modern for the time, and somewhat closed the performance gap between British and American airliners.