A prerequisite to aircraft performance analysis is the ability to calculate the aircraft drag under various flight conditions. One of the jobs of a performance engineer is to determine drag force produced by an aircraft at different altitudes, speeds, and configurations. The drag coefficient is a non-dimensional parameter, but it takes into account every aerodynamic configuration aspect of the aircraft, including large components such as wing, tail, fuselage, engine, and landing gear and small elements such as rivets and antenna. Drag force is the summation of all forces that resist against aircraft motion. The calculation of drag of a complete aircraft is a difficult and challenging task, even for the simplest configurations. The aircraft drag may be mathematically modeled by a variety of methods. It seems natural to seek the similarity of variation of drag due to a flight parameter to a standard figure or geometry.