Turboprop on 20 September 1945. From their experience with the Trent, Rolls-Royce developed the Rolls-Royce Clyde, the first turboprop engine to be fully type certificated for military and civil use, and the Dart, which became one of the most reliable turboprop engines ever built. Dart production continued for more than fifty years. The Dart-powered Vickers Viscount was the first turboprop aircraft of any kind to go into production and sold in large numbers. It was also the first four-engined turboprop. Its first flight was on 16 July 1948. The world's first single engined turboprop aircraft was the Armstrong Siddeley Mamba-powered Boulton
Vickers V-1000 Victor. Armed with nuclear weapons and powered by jet engines, these aircraft would be enter service during the 1950s as the V-bombers. The first of the V-bombers to enter service was the Valiant; observing the favourable performance attributes of the Valiant, both the Ministry of Supply (MoS) and Vickers became interested in a prospective transport derivative as a potential long-range successor to the smaller Comet. The RAF had also noticed a demand for a suitable transport aircraft capable of accompanying the V-bombers on deployments to any part of the world, carrying a mix of personnel and cargo needed for such