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The Travels of Mr. Fowler

Gemini Sparkle

Key Takeaways:

  • Invented by Harlan D. Fowler around 1920, the Fowler flap uniquely increases both wing camber and area by sliding aft before deflecting, providing a superior lift increase compared to other flap types.
  • This innovation significantly enhances aircraft performance, particularly for takeoff and landing by reducing speeds and distances, leading to its adoption by various aircraft manufacturers and its evolution into more complex multi-slotted designs.
  • Despite its high effectiveness, Fowler flaps are structurally complex, requiring robust actuation mechanisms for their long travel, and can present operational challenges such as generating too much lift during landing, which may impede braking.
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The Fowler flap was invented around 1920 by one Harlan Davey Fowler, an engineer who was then in the employ of the U.S. Army. An internet search for his name turns up, in addition to various references to his accomplishments in aeronautical engineering, a volume on the use of camels — the two-humped variety — as pack animals in the old West (Three Caravans to Yuma: The Untold Story of Bactrian Camels in Western America) and another on certain aspects of Christianity (Behold the Flaming Sword). I don’t know whether all these are the work of the same person, though there is no reason why a man cannot be an engineer, an historian and a religious adept in one lifetime. But there is also no reason two people cannot be named Harlan Davey Fowler. At any rate, I am less concerned with Fowler’s camels and swords than with his flaps.

The historical context is interesting. John Anderson of the Smithsonian, and other historians of aeronautics, have pointed out the curious lack of connection between the evolution of early aircraft designs and the pure science that anticipated them by many years. Theoretical aerodynamicists had scant contact with the designers and builders of actual airplanes. Flow phenomena had been studied in the laboratory decades before they were encountered anew on the flying field by scientifically illiterate builders and pilots; on the other hand, it sometimes happened that innovations were investigated in the laboratory only after they had appeared in the field. The development of lift-enhancing flaps displays that irregular intercourse between workshop and laboratory.

FLYING Staff

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