Investigations on V.P. Airscrews: A Description of the Work Carried Out in Connexion with the Development of a New Swiss Airscrew

COMPREHENSIVE research on the stress conditions of the airscrew hub, arising from the centrifugal forces which exceed 30 tons on each blade, have led to important advances in design which, with minimum dimensions and weight, allow the installation in the hub of the pitch‐adjusting mechanism. Some examples show how the basic principles of the design originated in complementary experimental and mathematical research; where calculation was abandoned owing to excessive complication in shape, the gap was filled by practical stress measurements, while, on the other hand, it was possible by calculation to extrapolate the results of experimental tests to points which were not accessible for direct measurement.