THE glider presents a simpler problem to the performance calculator than does the enginedriven aeroplane a problem free from the variables that are inevitably introduced when propulsion is derived from a complicated system of engine and airscrew. Nevertheless, the process of determining the performance to be expected of any projected glider design is usually quite a lengthy one and if, in addition, an investigation is to be made into the effects of varying all the factors concerned, with a view to finding their optimum values, the process becomes so lengthy that in practice it is sometimes neglected. Glider development then tends to proceed along what may be described as Darwinian lines, and progress becomes unnecessarily slow the evolution of gliders to fit new operational requirements as they arise takes longer than it need.
Aircraft Engineering and Aerospace Technology – Emerald Publishing
Published: Feb 1, 1942