Designated the Avro type 685, development began in 1941. The design paired a new "squared-off" fuselage with the wings, tail and undercarriage of the Lancaster bomber. Production was undertaken by Avro with the hopes of sales to both the RAF and in the postwar civil airliner market.
The prototype, LV626, was assembled by Avro's experimental flight department at Manchester's Ringway Airport and first flew there on 5 July 1942. It had initially been fitted with the twin fins and rudders of the Lancaster, but the increased fuselage side area forward of the wing compared to the Lancaster necessitated fitting a third central fin to retain adequate control and directional stability. Initial assembly and testing of production Yorks was at Ringway, later Yeadon (Leeds) and Woodford (Cheshire).
One pattern aircraft was built at Victory Aircraft in Canada, but no further orders were received. Victory tooled up for 30 of those aircraft and built parts for five with one ultimately being completed about the time the war came to an end.
The first civilian York (G-AGJA) was delivered to British Overseas Airways Corporation (BOAC) in 1944. One of the prototypes, named Ascalon, became a flying conference room for Winston Churchill; other Yorks were provided for the use of Lord Mountbatten when Viceroy of India, the Duke of Gloucester when Governor-General of Australia, and South African leader Jan Smuts. In RAF Transport Command service, the York was used on the England-India route.
Production orders included 50 civilian Yorks and 208 military versions to the RAF - many of which subsequently passed into civilian hands. During the Berlin Airlift, Yorks flew over 58,000 sorties - close to half of the British contribution, alongside the Douglas Dakota and Handley Page Hastings.
In the postwar years, BOAC used Yorks on their Cairo to Durban service, which had previously been worked by Shorts flying-boats. They were also used by British South American Airways and many private passenger and freight airlines.
When the Distant Early Warning Line (Dew Line) was being constructed in Canada in the late 1950s, the Avro York was introduced as a freighter by Associated Airways. At least one of the Yorks, CF-HAS, was retained, and was in service with Transair as late as 1961.
The Avro York was, like its stablemates, the Lancaster and Lincoln, a very versatile aircraft; one York, LV633 "Ascalon", was custom-built as the personal transport of Prime Minister Winston Churchill. Ascalon was to be fitted with a special pressurised "egg" so that VIP passengers could be carried without their having to use an oxygen mask. Made of aluminium alloy it had eight perspex windows to reduce claustrophobia. It also had a telephone, instrument panel, drinking facilities and an ashtray with room for cigars, thermos flask, newspapers, books. Testing at RAE Farnborough found the "egg" to work satisfactorily. However, Avro said it was too busy with the new Lancaster IV (Avro Lincoln) work so it was never actually installed in the Ascalon. It was considered for installation in the successor aircraft, a Douglas C-54B but the contractor Armstrong Whitworth decided it was impractical and the project was shelved. The whereabouts of "Churchill's Egg" are presently unknown.
MW104 "Endeavour" flew to Australia in 1945 to become the personal aircraft of HRH The Duke of Gloucester, Australia's then Governor-General. It was operated by the Governor-General's Flight and was the Royal Australian Air Force's only York.
Another aeroplane was fitted out as a "flying office" for Lord Mountbatten, then C-in-C South East Asia Command. During its first major overhaul at Manchester (Ringway) in 1945, the aeroplane was re-painted a light duck egg green, a shade intended to cool down the aeroplane, instead of its former normal camouflage colour scheme.
Crew: 5 (two pilots, navigator, wireless operator, cabin steward)
Capacity: 56 passengers
Length: 78 ft 6 in (23.9 m)
Wingspan: 102 ft 0 in (31.1 m)
Height: 16 ft 6 in (5 m)
Wing area: 1,297 ft² (120.5 m²)
Empty weight: 40,000 lb (18,150 kg)
Loaded weight: 65,000 lb (29,480 kg)
Powerplant: 4× Rolls-Royce Merlin 24 liquid-cooled V12 engines, 1,280 hp (950 kW) each
Maximum speed: 298 mph (258 knots, 479 km/h) at 21,000 ft (6,400 m)
Range: 3,000 mi (2,600 nm, 4,800 km)
Service ceiling: 23,000 ft (7,010 m)
Rate of climb: 820 ft/min (4.2 m/s)
Wing loading: 54 lb/ft² (260 kg/m²)
Power/mass: 0.079 hp/lb (130 W/kg)