Secrets of the Spitfire: The Story of Beverley Shenstone, the Man Who Perfected the Elliptical Wing, by Lance Cole, Pen and Sword Aviation, 2012, $39.95.
Reginald J. Mitchell will always be remembered as the mastermind behind the Supermarine Spitfire. But in Secrets of the Spitfire, Lance Cole focuses on the iconic fighter’s most distinctive feature and the man who developed it. Canadian Beverley Strahan Shenstone (1906-1979) was the genius in aerodynamic engineering who gave the Spitfire its elliptical wing.
The Greek Apollonius is said to have first coined the term elleipsis for a curved form that was something less than a perfect circle. Since then, many mathematicians and engineers have studied the properties of the curve, including its aerodynamic possibilities. In early 1894, Frederick Lancaster built a series of large flying models with thin elliptical planforms, and in 1906 Danish designer Jacob Ellehammer developed a successful airplane with an elliptical wing. Shenstone, however, was influenced by the studies of Nikolai Zhukovsky, while he was working on the research team of Alexander Lippisch, father of the delta wing, from 1930 to 1931. During the 1930s Shenstone and Lippisch continued to communicate about the flying problems they faced. In retrospect it seems curious that the Germans already knew of Shenstone’s application of mathematical principles toward developing an elliptical wing, while Shenstone already knew about Lippisch’s work on delta wings.
In 1937 Shenstone designed the first delta-wing bomber, the Supermarine B.12/36. For the Spitfire fighter, he succeeded in designing a double elliptical wing, having resolved the wing’s spanwise airflow circulation control largely based on what he had observed in the development of the Lippisch sweptwing (later used on the Messerschmitt Me-163 rocket plane) and delta-wing shapes. Through his delta-wing work and his study of German glider designs, Shenstone knew that the behavior of the airflow over the wing, as well as the wing loading itself, were the two key factors in creating an advanced wing. Applied to the Spitfire, it gave Britain a match for the Messerschmitt Me-109E when it most urgently needed such a plane.
Anyone interested in seeing how talented engineers seek and find solutions toward improving flight characteristics, and how mathematical theory makes its way from the drawing board to soaring reality, should find Secrets of the Spitfire a satisfying read.
Originally published in the November 2013 issue of Aviation History Magazine. To subscribe, click here.