Vickers V-1000 the world's first jet-powered commercial transport aircraft, the Vickers Viscount, the world's first turboprop-powered commercial airliner, and the Bristol Britannia, a turboprop-powered aircraft capable of conducting routine transatlantic flights; all of these designs had their origins in the specifications laid out by the wartime Brabazon Committee. With these aircraft, Britain appeared to be on track to capturing a large slice of the global demand for civil aircraft for the foreseeable future. Meanwhile, the Royal Air Force (RAF) had been pursuing development of a new generation of strategic bombers, these being the Vickers Valiant, the Avro Vulcan, and the Handley Page
Turboprop jet cruising speeds for most missions. The Bear would serve as their most successful long-range combat and surveillance aircraft and symbol of Soviet power projection throughout the end of the 20th century. The USA would incorporate contra-rotating turboprop engines, such as the ill-fated twin-turbine Allison T40 — essentially a twinned up pair of Allison T38 turboprop engines driving contra-rotating propellers — into a series of experimental aircraft during the 1950s, with aircraft powered with the T40, like the Convair R3Y Tradewind flying boat never entering U.S. Navy service. The first American turboprop engine was the General Electric XT31, first used