The Wittman D-12 "Bonzo" was an air racer designed by

Steve Wittman Sylvester Joseph "Steve" Wittman (April 5, 1904 – April 27, 1995) was an American air-racer and aircraft engineer. An illness in Wittman's infancy claimed most of his vision in one eye, which convinced him from an early age that his dre ...

for the Thompson Trophy races. The aircraft's top speed of made it faster than any United States military aircraft of the era.

Development

Wittman purchased a

Curtiss D-12 The Curtiss D-12, sometimes identified with the military designation Curtiss V-1150, was an aircraft engine of 18.8 liter displacement. It was a water-cooled V12, producing 443 hp (330 kW) and weighing 693 lb (314 kg). It was ...

engine in 1934, and designed "Bonzo" around it. In 1935, it took part in the Thompson Trophy Race. In 1936, a spring steel landing gear was installed. In 1937 a ducted fan was added to the spinner inlet, flaps were added and wingspan was reduced to . Ram air was added for the carburetors, and modified several times to get even fuel pressure.

Design

"Bonzo" featured a

mid-wing A monoplane is a fixed-wing aircraft configuration with a single mainplane, in contrast to a biplane or other types of multiplanes, which have multiple planes. A monoplane has inherently the highest efficiency and lowest drag of any wing confi ...

taildragger Conventional landing gear, or tailwheel-type landing gear, is an aircraft undercarriage consisting of two main wheels forward of the center of gravity and a small wheel or skid to support the tail.Crane, Dale: ''Dictionary of Aeronautical Term ...

design with a small squarish cross-section. The aircraft was finished in red and silver, like Wittman's smaller racer "Chief Oshkosh". The spinner featured a center cut-out to provide cooling air to a radiator. The wings were made of wood 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 ...

and closely spaced wing ribs.

Operational history

"Bonzo" was not ready for the 1934

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 ...

in time. ;1935 National Air Races:Bonzo places second behind "Mr.Mulligan" with a speed of . ;1936 National Air Races:Bonzo catches fire en route at

Cheyenne, Wyoming Cheyenne ( or ) is the capital and most populous city of the U.S. state of Wyoming, as well as the county seat of Laramie County, with 65,132 residents, per the 2020 US Census. It is the principal city of the Cheyenne metropolitan statistical ...

. ;1937 Thompson Trophy races:Engine trouble forces Wittman from lead to fifth at . ;1938 National Air Races:Third place with a leaking radiator. ;1939 National Air Races:Fifth place. The D-12 engine was sold to the Falin Propeller Co. for propeller testing throughout

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

Variants

* Only one Wittman D-12 "Bonzo" was built, but Wittman used the name "Bonzo" again on his second midget racer patterned after the Wittman Buster.

Aircraft on display

The D-12 "Bonzo" was donated by Wittman to anchor the

EAA Airventure Museum The EAA Aviation Museum, formerly the EAA AirVenture Museum (or Air Adventure Museum), is a museum dedicated to the preservation and display of historic and experimental aircraft as well as antiques, classics, and warbirds. The museum is lo ...

Oshkosh, Wisconsin Oshkosh is a city in Winnebago County, Wisconsin, of which it is the county seat. The city had a population of 66,816 in 2020, making it the ninth-largest city in Wisconsin. It is also adjacent to the Town of Oshkosh. History Oshkosh was ...

in December 1959, it was later restored for display in 1982.

Specifications (Wittman D-12 Bonzo)

References

{{Wittman aircraft Racing aircraft D-12 United States sport aircraft Single-engined tractor aircraft Mid-wing aircraft Aircraft first flown in 1935