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 Vellore Vickers Vellore The Vickers Vellore was a large biplane designed as a freight and mail carrier, in single-engined and twin-engined versions, which saw limited use as freighters and long-range experimental aircraft. A final variant with a broader fuselage, the Vellox, was built as an airliner. The Vickers Vellore, named after the Indian city of Vellore in the state of Tamil Nadu, was a response to Air Ministry specification 34/24, which called for a civil mail and freight carrier. It was a large single-engined two-bay biplane, metal framed and fabric covered. The wings were of equal span with a slight stagger