The Folkerts SK-3 a.k.a. ''"Jupiter, Pride of Lemont"'' was the third in a series of

air racers The atmosphere of Earth is the layer of gases, known collectively as air, retained by Earth's gravity that surrounds the planet and forms its planetary atmosphere. The atmosphere of Earth protects life on Earth by creating pressure allowing for ...

developed by

Clayton Folkerts Clayton Folkerts (1897–1964) was an American aircraft designer. Early life Self-taught in aircraft design, Clayton built five aircraft at his family farm between 1916 and 1926, including a Henderson powered high-wing. Folkerts worked ...

Design and development

The SK-3 was built for mechanic Rudy A. Kling from

Lemont, Illinois Lemont is a village located in Cook, DuPage, and Will counties in the U.S. state of Illinois, and is a south-west suburb of Chicago. The population was 17,629 as of the 2020 census. The village is situated on a hillside along the south banks of ...

as his personal racing aircraft. Kling assisted in the construction of the aircraft. The

Folkerts SK-2 The Folkerts SK-2, also known as Speed King Two, "Toots" and "Miss Detroit" was a racer built for the 1936 National Air Races Design and development Clayton Folkerts designed his second racer, the SK-2 ''Toots'' after leaving the Mono-Aircraft ...

was the basis for the aircraft, with a slight upscaling in size with a larger Menasco C6-S engine. The SK-3 was a midwinged conventional aircraft with retractable landing gear. The

fuselage The fuselage (; from the French ''fuselé'' "spindle-shaped") is an aircraft's main body section. It holds crew, passengers, or cargo. In single-engine aircraft, it will usually contain an engine as well, although in some amphibious aircraft t ...

was long and slender. The thin wings used

spruce A spruce is a tree of the genus ''Picea'' (), a genus of about 35 species of coniferous evergreen trees in the family Pinaceae, found in the northern temperate and boreal (taiga) regions of the Earth. ''Picea'' is the sole genus in the subfami ...

spar SPAR, originally DESPAR, styled as DE SPAR, is a Dutch multinational that provides branding, supplies and support services for independently owned and operated food retail stores. It was founded in the Netherlands in 1932, by Adriaan van Well, ...

plywood Plywood is a material manufactured from thin layers or "plies" of wood veneer that are glued together with adjacent layers having their wood grain rotated up to 90 degrees to one another. It is an engineered wood from the family of manufactured ...

covering, and incorporated split flaps. The fuselage was welded steel tubing with

aircraft fabric covering Aircraft fabric covering is a term used for both the material used and the process of covering aircraft open structures. It is also used for reinforcing closed plywood structures. The de Havilland Mosquito is an example of this technique, as ar ...

, built in two parts that were bolted together. The manual retractable landing gear used a single lever, rather than earlier crank systems. There were two forward fuel tanks, a main, and an auxiliary of mounted behind the cockpit. The Menasco C6-S was modified by Kling to produce at 3300 rpm, versus the standard output. Folkerts SK-3

Operational history

Rudy Kling was the exclusive pilot of the SK-3. Kling had only 150 hours experience in a J-5-powered Travel Air before flying the racer. In the 1937 Greve Race, Kling came in at first place at , just beating Wittman's Chief Oshkosh. At the 1937 Thompson Trophy race in the

National Air Races The National Air Races (also known as Pulitzer Trophy Races) are a series of pylon and cross-country races that have taken place in the United States since 1920. The science of aviation, and the speed and reliability of aircraft and engines grew ...

, he again won at . On December 3, 1937, during the 1938 Miami Air Races, the SK-3 crashed in the wash of a larger aircraft with Kling dying on his 29th birthday.

Variants

;SK-4 :Unlike other SK racers which were progressively improved, the SK-4 built at Kansas City municipal airport was a copy of the SK-3 aircraft with a goal of attaining a maximum speed from a new metal propeller.

Roger Don Rae Roger is a given name, usually masculine, and a surname. The given name is derived from the Old French personal names ' and '. These names are of Germanic origin, derived from the elements ', ''χrōþi'' ("fame", "renown", "honour") and ', ' ( ...

flew in the 1938 National Air Races, but dropped out due to

wing flutter Aeroelasticity is the branch of physics and engineering studying the interactions between the inertial, elastic, and aerodynamic forces occurring while an elastic body is exposed to a fluid flow. The study of aeroelasticity may be broadly classif ...

. In the 1939

, pilot Del Bush crashed. Folkerts did not build any more racers after the SK-4."Building a five-miles-a-minute racing plane."
''Popular Mechanics,'' August 1938, p. 223.

Specifications (Folkerts SK-3)

References

;Notes ;Bibliography * Foxworth, Thomas G. ''The Speed Seekers.'' New York: New York: Doubleday, 1976. . * Matthews, Birch. ''Race with the Wind: How Air Racing Advanced Aviation.'' Minneapolis, Minnesota: Zenith Publishing, 2001. . * Matowitz, Thomas G. Jr. ''Cleveland's National Air Races'' (Images of Aviation). Mount Pleasant, South Carolina: Arcadia Publishing, 2006. . * Schmid, Sylvester H. and Truman C. Weaver. ''The Golden Age of Air Racing: 1927–1933.'' Oshkosh, Wisconsin: EAA Aviation Foundation, 1983. . * Vorderman, Don. ''The Great Air Races.'' New York: Doubleday, 1969. {{refend Racing aircraft Mid-wing aircraft Single-engined tractor aircraft Aircraft first flown in 1937

Design and development

Operational history

Variants

Specifications (Folkerts SK-3)

See also

References