8. A Practical Method for Wing Weight Estimation

Paper

Abstract

In this paper Mr. Englebry states the need of a relative quick and accurate method of estimating the weight of the wing consistent with design criteria.
He outlines the effect of various items influencing the weight of the wing and develops a basic formula whereby all conditions are considered.
A chart is given tabulating the information necessary to plot estimation curves for any particular of wing construction, whereby quick estimates can be made for wings of similar construction. Curves are plotted for wings constructed by Lockheed Aircraft Corporation.
The problem of estimating wing weights is a very complex one, for no other major structural item of an airplane has so many varying factors that affect weight. There is a definite need for an estimating method, based on these varying factors that can be applied to any type of wing with reasonable accurate results. The attack of the problem must be based, however, on logic and be as simple as possible within the limits of reasonable accuracy. In other words, a compromise should be made between the simplest method of wing estimation, an estimate based on a similar model already constructed, and the most complex method, a complete stress analysis of the wing.
The purpose of this article is to present a method of wing weight estimation that is logical, practical, accurate, and, although complex in its derivation, simple to apply. Basically, the method was evolved from an equation of the bonding material required to sustain the air loads. It is applicable to all types of airplanes, and accounts for weight variations due to wing loading, span, thickness, taper ratio, load factor, and material. This method is also adaptable for use with particular types of structure instead of particular types of airplanes. Essentially, this means that a broader scope of estimates can be made; for most modern airplanes employ similar typos of wing structure.