Roy Chadwick the chief designer at Avro, used the redesign of the Avro Manchester as the inspiration to design a new, easily produced military transport aircraft. Designated the Type 685 York, the new aircraft would have good range and payload capability, achieved by matching a generously sized fuselage to the wings, tail, power plants and undercarriage developed for the Lancaster. Due to the need to concentrate on Lancaster production, work on the York prototype was delayed for two years, by which time Specification C.1/42 had been drafted around the design. This had been developed for the carriage of troops and freight, with a secondary assault capability. As this would involve the aircraft making a wheels up landing on the battlefield without damaging the engines and propellers, thus allowing the immediate delivery of troops and weapons, the aircraft would need a shoulder mounted wing and a strengthened lower fuselage. [N 2]
Four prototypes were built for initial testing; LV626, LV629, LV633 and LV639. After it's first flight, LV629 was fitted with Bristol Hercules radial engines, serving as the prototype of a radial engined variant which was ultimately not proceeded with. LV633 was assigned to 24 Squadron and given the name Ascalon.
York C.I aircraft TS789 to TS813 were among thirty examples passed to BOAC. Seven of these were later transferred to British South American Airways, to supplement the twelve they already owned. Another eight were operated by Surrey Flight Services, and several were built for Skyways Ltd.
- Green, William - Bombers. 1975. Page 207
- World Aircraft Information Files Aviation Partwork. Midsummer Books Ltd. File 21 Sheet 14 (World Military Aircraft:Avro Lancaster - York and Lancastrian)
- Robertson, Bruce. British Military Aircraft Serials 1912-1966. Ian Allen Ltd. 1967 Page 254
- Robertson, Bruce. Page 288