Harlan D. Fowler (1895-1982) was an American inventor, writer, and airplane engineer who invented the variable

wing A wing is a type of fin that produces lift while moving through air or some other fluid. Accordingly, wings have streamlined cross-sections that are subject to aerodynamic forces and act as airfoils. A wing's aerodynamic efficiency is expres ...

area

Fowler flap A flap is a high-lift device used to reduce the stalling speed of an aircraft wing at a given weight. Flaps are usually mounted on the wing trailing edges of a fixed-wing aircraft. Flaps are used to reduce the take-off distance and the landing ...

used on many commercial aircraft today.

Fowler flap

The Fowler flap combines a translation and a rotation. The flap splits and slides backwards, then rotates down creating one or more slots. These movements increase the wing's curvature which increases cord and

camber Camber may refer to a variety of curvatures and angles: * Camber angle, the angle made by the wheels of a vehicle * Camber beam, an upward curvature of a joist to compensate for load deflection due in buildings * Camber thrust in bike technology * ...

. The high-lift Fowler flap is located on the trailing edge of an airplane wing which increases wing area,

lift Lift or LIFT may refer to: Physical devices * Elevator, or lift, a device used for raising and lowering people or goods ** Paternoster lift, a type of lift using a continuous chain of cars which do not stop ** Patient lift, or Hoyer lift, mobile ...

, and drag. The flap often forms part of the upper surface of the wing similar to a plain flap or a split flap, but upon extension it slides rearward before lowering. Fowler flaps always feature one or more slots. The Fowler flap complex movement requires special guidance systems on the lower surface, called "flap rails". The Fowler flap itself can be in several parts, with several slots. Starting in the summer of 1927 with mechanic Stanley Crowfoot, Fowler privately designed, tested, and funded the development of the Fowler flap. Testing by

Fred Weick Fred Ernest Weick (1899–1993) was an airmail pilot, research engineer, and aircraft designer. Working at the NACA, he won the 1929 Collier Trophy for his design of the NACA cowling for radial air-cooled engines. Weick's aircraft designs inc ...

at the

National Advisory Committee for Aeronautics The National Advisory Committee for Aeronautics (NACA) was a United States federal agency founded on March 3, 1915, to undertake, promote, and institutionalize aeronautical research. On October 1, 1958, the agency was dissolved and its assets ...

(NACA) realized the Fowler flap would reduce landing speed, decrease landing and take-off runs, and improve climbing ability. The first aircraft to use the Fowler flap included the

Martin 146 The Martin Model 146 was an unsuccessful American bomber design that lost a 1934–1935 bomber design competition to the prototype for the Douglas B-18 Bolo (itself soon supplanted by the B-17 Flying Fortress). Design and development Although ge ...

prototype in 1935, the German

Fieseler Fi 97 The Fieseler Fi 97 was a 1930s German four-seat cabin touring and competition monoplane aircraft designed and built by the German manufacturer Fieseler. Design and development Following the success of their two-seat tourer/trainer the Fieseler ...

, and the

Lockheed Super Electra The Lockheed Model 14 Super Electra was an American civil passenger and cargo aircraft built by the Lockheed Aircraft Corporation during the late 1930s. An outgrowth of the earlier Model 10 Electra, the Model 14 was also developed into larger, ...

in 1937. Other early adopters of the Fowler flap included the Boeing B-17,

B-29 The Boeing B-29 Superfortress is an American four-engined propeller-driven heavy bomber, designed by Boeing and flown primarily by the United States during World War II and the Korean War. Named in allusion to its predecessor, the B-17 Fly ...

, and

Lockheed P-38 Lightning The Lockheed P-38 Lightning is an American single-seat, twin piston-engined fighter aircraft that was used during World War II. Developed for the United States Army Air Corps by the Lockheed Corporation, the P-38 incorporated a distinctive twi ...

. Many modern commercial aircraft use Fowler flaps. In 1948 Fowler published the text, ''Fowler Flaps for Airplanes: An Engineering Handbook.''

Life

Born Harlan Davey Fowler on June 18, 1895 in Sacramento, California. As a teenager he built

Man-lifting kite A man-lifting kite is a kite designed to lift a person from the ground. Historically, man-lifting kites have been used chiefly for reconnaissance. Interest in their development declined with the advent of powered flight at the beginning of the 20 ...

s. He married twice and had two children. Fowler's aeronautical engineer career started in 1917 with the Signal Corps and he worked in the engineering division as assistant engineer in charge of design at

McCook Field McCook Field was an airfield and aviation experimentation station in Dayton, Ohio, United States. It was operated by the Aviation Section, U.S. Signal Corps and its successor the United States Army Air Service from 1917 to 1927. It was named fo ...

in Dayton, OH. Fowler was an independent aeronautical consultant for:

Fokker Fokker was a Dutch aircraft manufacturer named after its founder, Anthony Fokker. The company operated under several different names. It was founded in 1912 in Berlin, Germany, and became famous for its fighter aircraft in World War I. In 1919 ...

Glenn L. Martin Glenn Luther Martin (January 17, 1886 – December 5, 1955) was an early American aviation pioneer. He designed and built his own aircraft and was an active pilot, as well as an aviation record-holder. He founded an aircraft company in 1912 whi ...

, Convair, Douglas Aircraft, the Bureau of Aeronautics, and the

U.S. Air Force The United States Air Force (USAF) is the air service branch of the United States Armed Forces, and is one of the eight uniformed services of the United States. Originally created on 1 August 1907, as a part of the United States Army Signal ...

. From 1922 to 1925 Fowler worked with

G Elias & Brother G Elias & Brother was and American manufacturer of cabinets and aircraft based in Buffalo, New York in the 1920s. A.G. Elias sat on the Manufacturers Aircraft Association's board of directors along with President Frank H. Russell, VP Glenn L ...

of Buffalo, NY, the Aeromarine Plane and Motor Company, and the

Naval Aircraft Factory The Naval Aircraft Factory (NAF) was established by the United States Navy in 1918 in Philadelphia, Pennsylvania. It was created to help solve aircraft supply issues which faced the Navy Department upon the entry of the U.S. into World War I. ...

where he worked on the airship

USS Shenandoah (ZR-1) USS ''Shenandoah'' was the first of four United States Navy rigid airships. It was constructed during 1922–1923 at Lakehurst Naval Air Station, and first flew in September 1923. It developed the U.S. Navy's experience with rigid airships and ...

. Also he worked at

Pitcairn Aircraft Company The Pitcairn Aircraft Company was an American aircraft manufacturer of light utility aircraft. An early proponent of the autogyro, the company, later known as the Autogiro Company of America among other names, remained in business until 1948. ...

designing the

Mailwing The Pitcairn Mailwing family was a series of American mail carrier and three-seat sport utility biplane aircraft produced from 1927 to 1931. Design and development The Pitcairn Mailwings were developed to carry air mail for the United States P ...

. In 1928 Fowler worked as the Chief Aeronautical engineer for John M. Miller III of the Miller Aviation Corporation of New Brunswick, NJ. In May 1929, Fowler started the Fowler Airplane Wings Inc. hoping to market his Fowler flap just prior to the

Wall Street Crash of 1929 The Wall Street Crash of 1929, also known as the Great Crash, was a major American stock market crash that occurred in the autumn of 1929. It started in September and ended late in October, when share prices on the New York Stock Exchange colla ...

. Fowler started his own company purchasing $50,000 of new shares on 17 December 1941, not to be confused with the WWI company

Fowler Airplane Corporation The Fowler Airplane Corporation was an aircraft manufacturing company that operated in San Francisco, California, from 1918 into the 1920s. It was founded by Robert G. Fowler, the first person to make a west-to-east transcontinental flight in stage ...

, he became president of the Fowler Aircraft Company from the insolvent Hardman Aircraft Products Inc. of San Diego, CA. Despite having hearing difficulties and used a hearing aid, he continually lobbied the NACA with multiple ideas to improve aircraft. NACA engineer Ken Mort would help Fowler build models and test many of his aeronautical concepts. Ahead of his time, Fowler developed his flap designed when airplanes were still covered with fabric. Harlan Fowler retired in 1975 and died on April 27, 1982. His original research papers including technical reports, blueprints, original data, drawings, photographs, models of the Fowler flap, and air cargo container models are archived at San Jose State University. San Jose State University's ''Harlan D. Fowler Memorial Scholarship'' is named in his honor. He holds at least four patents.

Works

* Harlan D. Fowler, ''Fowler flaps for airplanes'', an engineering handbook, Los Angeles, Wetzel Publications, 6 May 1948 * Harlan Davey Fowler , ''Camels to California'': A Chapter in Western Transportation , Vol. 7, Stanford University Press,1950, 93 p.. * Harlan Davey Fowler , ''Three caravans to Yuma'': the untold story of Bactrian camels in western America , AH Clark Co.,1980, 173 p. ( , ). * Harlan Davey Fowler , ''Behold the Flaming Sword'': Biography of John and Jesus , Vantage Press,1983 ( , ).

Reference section

{{DEFAULTSORT:Fowler, Harlan D. 1895 births 1982 deaths People from Sacramento, California American aerospace engineers Aviation inventors 20th-century American inventors Aviation history of the United States Aviation pioneers