AST - A Fifth Engine For Environmental Consideration

No greater contribution seems to exist for improving supersonic transport economics than by improving the state of the art of jet noise suppressors. Exact matching of thrust requirements for supersonic cruise, transonic acceleration, climb, and especially takeoff-climb is complex. The present design becomes an equivalent five-engine configuration, where the extra thrust is required to enable environmental levels of FAR Part 36 to be achieved. The added size is required first to allow for engine throttling during takeoff run to provide reduced exhaust velocity and exhaust gas temperature consistent with suppressor structural limits, and secondly to make up for suppressor losses at takeoff flight speeds. As the engine selection must be closely tied to airplane selection, substantiation of the 2.2-M airplane selection is described.