Avro Tudor
The Avro Tudor was a British four-engined airliner developed from Avro's Lincoln bomber, and Britain's first pressurised airliner. Designed under the Brabazon Committee's postwar programme for the North Atlantic route, it needed two years of stability work before BOAC rejected it in 1947. British South American Airways flew the lengthened Tudor IV, but Star Tiger and Star Ariel disappeared over the Atlantic in 1948 and 1949 and were never found. Tudor 5s served as fuel tankers in the Berlin Airlift, and converted freighters worked on into the 1950s. Only thirty-eight were completed, split across seven marks, and the type was retired in 1959.
Why It Mattered
The Avro Tudor was Britain's first pressurised airliner. It was designed to Specification 29/43, which called for a commercial adaptation of the Lincoln bomber, under the Brabazon Committee's recommendations for postwar British civil aircraft. The Tudor I was intended for the North Atlantic route, where American rivals already carried more passengers and weighed less. After two years of design changes, BOAC rejected the aircraft in April 1947 as incapable of North Atlantic operations. Production was small and split across marks: twelve Tudor 1s, five Tudor 2s, two Tudor 3s, twelve Tudor 4s, six Tudor 5s and one Tudor 7, thirty-eight aircraft in all. Two of the Tudor IVs flown by British South American Airways disappeared over the Atlantic, in January 1948 and January 1949, and were never found.
Design Notes
Roy Chadwick designed the Tudor under wartime restrictions that barred a completely new aircraft, so he kept the Lincoln's wing and matched it to a new pressurised fuselage of circular cross-section. The design retained the Lincoln's four Rolls-Royce Merlin engines, and the Tudor I carried a crew of five with provision for up to twenty-four passengers. Its main wheels retracted into the inboard engine nacelles, but the gear ended in a fixed tailwheel, a layout already judged obsolete. Testing exposed longitudinal and directional instability, and the Royal Aircraft Establishment's programme of work produced a larger tailplane and larger vertical surfaces in place of the original fin and rudder. The Tudor 2 was a larger aircraft, twenty-five feet longer and a foot wider in the fuselage, meant to carry up to sixty passengers on the Empire air routes. Avro also flew one Tudor 7 with Bristol Hercules radial engines, and rebuilt the second Tudor I prototype as the Tudor 8 with four Rolls-Royce Nene turbojets in paired underwing nacelles.
Operational History
The prototype Tudor, G-AGPF, first flew at Ringway in Manchester on 14 June 1945. Testing it and the following prototypes revealed aerodynamic problems that took some two years of major design changes to address. After tropical trials, and having asked for some 340 changes, BOAC announced in April 1947 that it considered the aircraft incapable of North Atlantic operations. In August 1947 the Tudor 2 prototype crashed on takeoff from Woodford, killing Avro's designer Roy Chadwick; investigators later found that the aileron control circuit had been incorrectly assembled. Of the Tudor 1s in production when BOAC withdrew, two were converted into VIP Mk 3s for ministerial use and the remainder were lengthened to become the Mk 4 and Mk 4B. British South American Airways took delivery of its first Tudor 4 in September 1947 and flew it out to South America the next day. On the night of 29–30 January 1948, the Tudor IV Star Tiger disappeared without trace between Santa Maria in the Azores and Bermuda, with thirty-one people on board; the cause was never determined. On 17 January 1949 Star Ariel also disappeared, between Bermuda and Kingston, Jamaica, with the loss of twenty people, and the Tudor IVs were grounded once more. The fleet shortage that followed led to BSAA being taken over by BOAC, and the remaining Tudor IVs flew on as unpressurised freighters. The Tudor 5s, which never entered passenger service, were stripped of their fittings and used as fuel tankers on the Berlin Airlift, completing 2,562 supply sorties and carrying 22,125 tons of fuel into Berlin. One Tudor 5, returned to passenger service with Airflight on a charter from Ireland, crashed on approach at Llandow in South Wales on 12 March 1950, killing eighty of those on board.
Afterlife
Freight work kept the type employed through the 1950s: Air Charter's Tudor IVs, fitted with large cargo doors by Aviation Traders and designated Super Traders, flew long-distance freight as far as Christmas Island. From 1954 Air Charter also operated a fleet of six Tudor 4B Super Traders from Stansted, flying stores and equipment to Adelaide for the Woomera rocket range. Two of those aircraft were lost on return flights in 1959: G-AGRG was burnt out at Brindisi in January, and G-AGRH crashed on Mount Suphan in Turkey in April. The type was retired from service in 1959. The jet-powered Tudor 8 had already been broken up in 1951 after its high-altitude tests, and the British Aircraft Directory records no Tudor preserved in a British museum.