In the period from 1950 to 1970, the development of VTOL capability in fixed wing aircraft was energetically pursued in many parts of the world. The larger proportion of this effort was dedicated to machines featuring composite powerplants. In these vertical thrust was wholly or partly provided by lift engines designed for the purpose. A number of sophisticated experimental aircraft of this type were built and flown in Europe, all of which featured Rolls-Royce lift engines. Many technical problems were encountered and overcome in the field of engine design and powerplant installation. New and rigorous methods of design validation were introduced. The technology base and engineering disciplines which grew out of this experience had a strongly beneficial influence on all engine and powerplant design. The accumulated experience remains highly relevant to new aircraft projects planned with VTOL capability, where a composite powerplant provides the optimum performance.
