119. Experimental Inertia Determination

Paper

Abstract

The Weight Group is in a spectacularly unique position in the aircraft business. No other technical (or non-technical) group receives the complete, over-all aircraft picture while threading their way through the detailed design of each and every component. To rephrase the usual saying ‘ The weight engineer must see the forest as well as the trees’
Of course this unique position since it involves detailed information about all airplane components, results in the allocation of some arduous and onerous duties to the Weight Group. One of these is the computation of the Moment so Inertia of the complete airplane as well as the inertias of some sundry components such as control surfaces, externals stores, and all other items which have an independent motion of their own.
The usual chronological steps in arriving at these results are: first, a rough approximation of the total inertia based on the outlines and assumed weight distribution; later an accurate calculation based on finished detailed drawings; and finally (in the case of control surfaces, some store and airplane component ) an experimental determination. It is with this final step this paper is chiefly concerned.