LANGLEYS AERONAUTICAL RESEARCH - A MODERN CRITIQUE AND REASSESSMENT

Samuel Langley, third Secretary of the Smithsonian, was also the first U.S. government in-house researcher in aerodynamics. By 1890, he had carried put a carefully conceived, accurately engineered series of aer odynamic experiments that provided a database for the design of his st eam-powered aerodromes, successfully flown in 1896. Langley's work is examined from a modern perspective. The aerodrome flights of 1896 are discussed. Particular emphasis is placed on a reassessment of Langley' s aerodynamic experiments and data. The Langley law for the variation of power required as a function of velocity, which was immediately con troversial in his time and remained so until the present, is finally e xplained for the first time, and the controversy removed. Also, Langle y produced the first definitive data showing the aerodynamic superiori ty of high-aspect-ratio wings. Those data, if they had been properly a ppreciated by the Wright brothers, might have greatly improved their e arly glider designs. This presentation also compares and contrasts Lan gley's aerodynamic data with the contemporary data of Lilienthal. In g eneral, Langley's aerodynamics, vis-a-vis the aerodynamics of Lilienth al and the Wright brothers, is brought into clearer focus.