Register

The Travels of Mr. Fowler

Gemini Sparkle

Key Takeaways:

  • The Fowler flap, invented around 1920, revolutionized high-lift devices by uniquely increasing wing area through an aft-sliding motion before deflection.
  • This mechanism combined variable wing area with camber change and a stall-delaying slot, providing greater lift than other flaps and being particularly advantageous for takeoff due to low initial drag.
  • Widely adopted by aircraft like the C-130 and evolving into multi-slotted systems for large airliners (e.g., Boeing 727, 737), the Fowler flap significantly improved maximum lift coefficients.
  • However, its complex actuation hardware makes it structurally inconvenient, and its powerful lift generation can lead to operational issues, such as diminished braking effectiveness on landing.
See a mistake? Contact us.

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

FLYING Magazine is a one-stop resource for everything aviation, including news, training, aircraft, gear, careers, photos, videos, and more.

Ready to Sell Your Aircraft?

List your airplane on AircraftForSale.com and reach qualified buyers.

List Your Aircraft
AircraftForSale Logo | FLYING Logo
Pilot in aircraft
Sign-up for newsletters & special offers!

Get the latest stories & special offers delivered directly to your inbox.

SUBSCRIBE