Regional airliner were replaced by progressively longer-range designs. In the immediate post-war era these were typically Douglas DC-3s, although even the De Havilland Dragon Rapide biplane airliner remained in service for some time. This "hand-me-down" process of supplying aircraft continued with designs like the Convair 440, Douglas DC-6 and Vickers Viscount also serving in this role while the first jets were introduced. By the mid-1950s, demand for even more economical designs led to the production of the first custom feederliners. These were almost always turboprops, which had fuel economy on par with piston engine designs, but had far lower maintenance costs. Often
Vickers Viscount the Vickers Vanguard. The Vanguard drew extensively from the knowledge and design of the Viscount, and likewise maintained its advantage of lower operating costs over pure jet-powered aircraft, but its disadvantage in being slower than jet aircraft became increasingly critical as jets became more available over time. Regular passenger flights were launched by BEA in 18 April 1953, the world's first scheduled turboprop airline service. BEA became a large user of the Viscount, as well the rival Handley Page Dart Herald; by mid-1958 BEA's Viscount fleet had carried over 2.75 million passengers over 200,000 flight hours. Following BEA's launch of