A study of the world altitude records for heavierthanair aircraft homologated by the Fdration Aronautique Internationale is interesting, and yields the information that from 1909 to 1914 the mean rate of increase of ceiling was almost 4,500 ft. per year, while from 1920 to 1936 the mean rate dropped to 1,000 ft. per year. Slumps, depressions and other financial phenomena must obviously have a repercussive influence in this particular field of aircraft development, and a pertinent example of their effect is provided by the unfortunate hiatus which occurs from 1914 to 1920, and obscures the height at which the change in rate takes place. It has been shown by Mr. McKinnon Wood, in an unpublished paper on the design of an aeroplane to reach a great height, written in November, 1931, that the power which the engine must develop at ceiling increases as the ceiling is raised, and that, in the case of a supercharged engine, the difference between the supercharged height and the ceiling of the aircraft decreases as the ceiling increases. Thus, to maintain the initial rate of increase of ceiling an accelerating rate of progress in engine design was necessary, but unlikely in view of the increasing number and difficult nature of the problems to be encountered and solved.
Aircraft Engineering and Aerospace Technology – Emerald Publishing
Published: Dec 1, 1936