The Lateral Stability of Aeroplanes: A New Geometrical System of Analysis

The following series of articles presents a new geometrical system of determining the lateral stability of aeroplanes. The method is intended to appeal particularly to engineers on account of two advantages: it is simple and rapid in operation, and gives a clear insight into the several factors governing the stability. Thus, whereas in the classical method stability calculations entail the drawing and analysis of quartic curves, the results are here obtained, and with greater generality, merely by the use of curves of the second degree. Furthermore, the effects of typical changes in design characteristics may easily be assessed with the minimum of effort. The fundamental analysis is essentially mathematical and follows the treatment first laid down by G. H. Bryan in 1911 and since developed by Bairstow, Glauert, Jones and Bryant. Physical explanations are included where possible to amplify the underlying principles.