The effectiveness of a military aircraft is a function of a number of characteristics, such as speed, maneuverability, range/payload combinations, weapons carried, electronic countermeasures, and visibility to the enemy's detection systems. In the aircraft design sequence, the emphasis during the early phases tends to be on the trades among familiar performance characteristics such as the first three above, with the others, including the radar cross-section (RCS), being progressively addressed later as the design is refined and detailed. One consequence of this sequence is an appreciable weight penalty due to design measures necessary for control of RCS. A lighter, lower-cost aircraft would result if all these characteristics were considered from the beginning, for two reasons; a more nearly optimum balance would be achieved among the characteristics affecting aircraft effectiveness, and design choices would be made which help to control RCS without appreciably degrading aero performance. The problem is the lack of an organized, proven body of trade data and guidelines on the relationship of RCS to the familiar aircraft design parameters. This paper describes an effort aimed at supplying that need.

In a complete description of an aircraft design, there are a multitude of parameters, ranging from gross characteristics such as type of wing planfom or engine location, through basic trade parameters such as wing sweep, wing area, or tail cant, to design details such as antenna type or surface discontinuities around access doors. Fortunately, no one of these parameters is extremely critical for both aero performance and RCS. Hence, armed with adequate knowledge, the designer can choose parametric values which yield the optimum RCS with minimal weight impact either through the direct effect of added treatment material or indirectly through aero performance degradation.