Hawker Siddeley Trident 1978, 117 Tridents had been produced. BEA's successor British Airways withdrew its Tridents by the mid-1980s. Trident services ended in China in the early 1990s. In 1953, as British European Airways (BEA) introduced the world's first turboprop-powered civil airliner – the Vickers Viscount – into passenger service, the operator was already considering what would be required of a potential successor. Following the entry into service of jet airliners in 1952, many airline managers and economists remained sceptical and advocated turboprop airliners as replacements of piston-engined airliners. In 1953, while several manufacturers across the world were investing in pure jet-powered aircraft,
Turboprop in the experimental Consolidated Vultee XP-81. The XP-81 first flew in December 1945, the first aircraft to use a combination of turboprop and turbojet power. The technology of the Allison's earlier T38 design evolved into the Allison T56, with quartets of the T56s being used to power the Lockheed Electra airliner, its military maritime patrol derivative the P-3 Orion, and the widely produced C-130 Hercules military transport aircraft. One of the most produced turboprop engines used in civil aviation is the Pratt & Whitney Canada PT6 engine. The first turbine-powered, shaft-driven helicopter was the Kaman K-225, a development of Charles