Engine Selection Problems for Jet Powered Ultra STOL

This paper discusses the effect of engine size and cycle on two types of Ultra STOL aircraft. One type, a powered lift plus deflected cruise thrust vehicle, is analyzed to determine the effect of wing loading, cruise engine, lift engine thrust loading, number of lift engines, cruise engine bypass ratio, and turbine inlet temperature on airplane gross weight and cost at a 1000-ft field length. The other type, a conventional nondeflected thrust airplane, is analyzed to determine the effect of wing loading, thrust loading, engine bypass ratio, and turbine inlet temperature on airplane gross weight and cost at field lengths from 1000-2000 ft. Results of this analysis indicate that powered lift aircraft are not cost competitive unless field lengths of less than 1000 ft are considered.