33. Some Problems in the Selection of Optimum Airplane Configurations for Minimum Weight

Paper

Abstract

The configuration of an airplane is, in general, defined by its external geometry. In other words by the wing area, aspect ratio, tail length, size of fuselage, length of landing gear, location of engines, etc. In selecting an optimum configuration for any new design, it is first necessary to determine the effects on weight of variations in geometry, both direct and indirect. Since practical considerations will normally preclude the use of unlimited time in making the necessary investigations, it is apparent that complete structural analysis and weight calculations of the large number of possible configurations would be extremely difficult. Conversely, it may be stated that within a given time increment or limit, the number of different configurations investigated will determine the degree to which we approach the optimum design. This corollary presents the weight engineers of the nation with a tremendous responsibility together with an equivalent amount of opportunity, and stresses the importance to the whole aircraft industry of the interchange of information which will permit the development of reliable formulae and weight estimating methods.