An Approach to the ANALYTICAL Design of Aircraft

FOR preliminary design work on transport airplanes, a graphical method is outlined for determining the effect which changes in a set of chosen major design variables will have on the airplane's ability to meet a given set of specifications and regulations.

Engines, propellers, and wing geometry are selected. Then for each condition laid down as a specification or regulation, a limiting curve of maximum weight allowed by the condition is plotted as a function of wing area. These curves are developed from basic data and standard equations.

If it is possible to meet all the conditions, the limiting curves - when plotted together on one graph - will enclose an area on the “allowable” side of all curves.