Avro 691 Lancastrian Jet
|JET ENGINE TESTBED, RESEARCH TRANSPORT||Virtual Aircraft Museum / United Kingdom / Avro|
The Lancastrian, a high-speed transport derived from the Lancaster bomber, was an ideal vehicle for testing the new jet and turboprop engines that were becoming ready for flight testing from the end of World War II. Some of these engines were for combat aircraft, but even so needed endurance flying to enable them to mature quickly and become reliable and well developed before being fitted to new civil machines.
First to fly was Lancastrian VH742, delivered to the Rolls-Royce flight development airfield at Hucknall in October 1945. Its outer Merlin engines were removed and the nacelles were also taken away, while the fuel system was completely rebuilt to carry both gasoline for the inner engines and kerosine for the new jets. In the outer positions were added completely new nacelles housing Nene turbojets, then the most powerful jet engines in the world. It flew again on August 14, 1946 with two Merlins and two Nenes.
On September 19, 1946 this aircraft acted as the world's first jet airliner by making three passenger flights carrying representatives of the Press as well as Ministry officials and other passengers (who were all most impressed and suggested that an airline that could offer jet travel would be the talk of the world). Rolls-Royce also flew a second Nene-Lancastrian, VH737, and two Avon-Lancastrians, VM732 and VL970. The latter was used for almost six years, its later flying being concentrated on the Avon 502 civil turbojet for the Comet 2 airliner.
The original engine for the first jet airliner to enter service, the Comet 1, was the de Havilland Ghost 50. This was tested in the outer positions of Lancastrian VM703, first flown with the jets on July 24, 1947. As the original intention with the Comet was to use rockets to boost thrust on takeoff, VM703 was also used to test the only rocket then available, the captured German Walter 109-500, two of which were fixed under the fuselage. A second Ghost-Lancastrian, VM729, handled the final development and certification flying of the Ghost 50 for the Comet 1 so that Comet development from July 1949 began with a reliable and mature engine.
Among other jet Lancastrians were VM733 with Armstrong Siddeley Sapphires, and various test-beds with the Canadian Orenda, Swedish Dovern and the British ASX, Adder and Viper. Turbo-props included the Dart, Mamba and Python.
Bill Gunston "The Illustrated Encyclopedia of Commercial Aircraft", 1980