The cost of noise reduction for powered-lift S.T.O.L. aircraft

Abstract

The direct operating costs and noise impacts of a wide variety of Externally Blown Flap and Augmentor Wing STOL short haul transport aircraft designs were evaluated to study the costs of noise reduction for these types of aircraft. The "two-stream" Augmentor Wing designs were found to be capable of the greatest noise reductions, and to have the lowest direct operating costs at all levels of noise impact. Sideline noise levels of 81 PNdB at 500 feet were attainable for an 80 seat aircraft with an 8 to 15 percent increase in direct operating cost over an aircraft designed with no constraints on noise.