The aerodynamic features of the C-5A discussed will include only those items which posed a significant challenge to the aerodynamicist: airfoil sections, high lift systems, and control and augmentation systems.
While the cruise configuration is quite conventional in that the C-5A uses a moderately swept wing, a tee-tail, and wing-pylon-mounted engines, the design requirements for forward and aft straight-in fuselage loading coupled with the provision of personnel accommodations, airdrop capability, and extremely high flotation, dictated fuselage and landing gear configurations which required an intensive effort to reduce aerodynamic drag to an absolute minimum level. This effort will be discussed.
The design of the high lift system was dictated by extremely stringent airport requirements and the high wing loading necessary to achieve optimum matching of airframe and engine in the cruise regime. In addition, the use of a modest thrust-to-weight ratio, coupled with a high thrust lapse rate with speed aggravated the difficulties associated with development of a suitable high lift system. The methods used to achieve the necessary aerodynamic high lift system performance while satisfying structural requirements are discussed.