Design of the Rolls-Royce Dart turboprop engine began in April 1945 and completed by June 1946. The engine first ran in July 1946, and first flew in the nose of a Lancaster testbed aircraft in October 1947. A major contribution to the initial success of the Dart was its selection for the Vickers Viscount, the first turboprop-powered airliner. Powered by four 932 KW (1,250 shp) Dart Mk. 504 engines, the prototype Viscount 630 first flew in July 1948. Ultimately, the Dart was upgraded to develop more than 2,237 KW (3,000 shp). Production ended in 1987, with 7,100 engines delivered.Other commercial aircraft using the Dart were the Fokker F.27 Friendship, Fairchild Hiller 227, Hawker Siddeley 748, Grumman Gulfstream I, and NAMC YS-11. Military versions powered such aircraft as the Breguet Alize, Handley Page Herald, Armstrong Whitworth Argosy, Avro 748, and Andover CC Mk. 2. This artifact powered the Vickers Viscount 806.