952. The Growth Factor Concept

Paper

Abstract

Under the assumption of constant performance, a simple equation relating airplane gross weight to the sum of the component weights is obtained. Then, an expression for the growth factor is derived by implicit differentiation of gross weight relative to fixed weight, a term of the basic gross weight equation. Variations in gross weight relative to changes in other design parameters are not presented; however, the weight equation can readily be modified to obtain these relationships.
Growth factors for rotary wing vehicles are distinguished from growth factors relative to fixed wing aircraft. The rotor weight fraction is shown to be constant under the assumptions.
Alternatively, maintaining geometry fixed, a fundamental approach is presented for obtaining growth factors corresponding to changes in weight empty.
The converse consideration of changes in weight empty corresponding to changes in design weights is briefly discussed.