Wittman D-12 Bonzo

Sylvester Wittman (1904-1995), known as "Witt" or "Steve" to his friends, was one of the greatest-possibly the greatest-pylon (closed-course) air race pilot in history. Between 1926 and 1989, he competed in and won more air races than anyone else. He built some of the world's most successful race airplanes. He designed and patented the spring landing gear later used in Cessna airplanes. He and Bill Brennand effectively invented Formula Vee (Volkswagen-powered) air racing. The airport at Oshkosh, Wisconsin, site of the world's largest aviation convention, bears his name.

Wittman learned to fly in 1924, in a surplus Standard J-1 biplane he bought with a friend. He entered his first air race two years later in Milwaukee, and he first competed in the National Air Races in Florida in 1928. In 1931, he moved to Oshkosh, Wisconsin to operate the Oshkosh airport. There, he designed and built "Chief Oshkosh," his first homebuilt racer. With engines ranging from 90 to 150 horsepower, Chief Oshkosh won many races between 1931 and 1937 and placed "in the money" in many others, often competing against much more powerful aircraft. In 1937 Wittman piloted the Chief to a world record for its class, of 238.22 mph.

In 1934, Wittman set his sights on the famed Thompson Trophy Race, a pylon race for aircraft of unlimited size and power. Without any formal training in aeronautics, Witt designed and built Bonzo, specifically for the Thompson Trophy Race. The design was dictated by the engine and Wittman's choice of engine was dictated by his lack of funds. He chose an obsolete Curtiss D-12 engine, the same type as was used in Curtiss-Schneider Trophy Race winners in the mid-1920s. Wittman's race plane designs emphasized light weight rather than sophisticated streamlining. Bonzo's fuselage was no larger than it had to be to hold the big V-12 engine, giving it an odd, angular look that the race press called "a flying barn door." The wings, built of wood, did not have the strong, heavy plywood skins typical of race planes of the day. Instead, Wittman spaced the wing ribs twice as close together as in normal wing construction. With a doped fabric skin, the extra ribs gave the wings the strength needed at race speeds.

In its first Thompson Trophy Race-1935-Bonzo finished second behind Harold Neumann flying "Mr. Mulligan." Flying Bonzo cross-country to the 1936 National Air Races in Los Angeles, Wittman landed in Cheyenne, Wyoming, where an engine backfire set Bonzo on fire. The fire was quickly put out but Bonzo was damaged too much to compete that year. A year later, at the 1937 Thompson Trophy Race, Wittman flew a rebuilt Bonzo to the fastest qualifying time-more than 275 miles per hour. He led the field for 18 of the race's 20 laps, until a rough engine forced him to throttle back and finish in fifth place. In the 1938 National Air Races, Wittman and Bonzo placed third and in 1939, in the last Thompson race before WW II, Wittman and Bonzo placed fifth. Throughout its racing career, Bonzo faced competitors with more horsepower and more financial backing, yet Bonzo remained a serious and respected adversary among unlimited pylon racers. In its final configuration, Bonzo could achieve 325 miles per hour-faster than the fastest U.S. military fighter planes of the day-on just 485 horsepower.

Steve Wittman and Bonzo

When unlimited air racing resumed after WW II, it was dominated by modified WW II fighter aircraft. The days of the homebuilt racer were gone and Bonzo retired. Wittman continued racing and winning in a variety of airplanes until his retirement in 1989 at age 85.
Wing Span 17 ft. 2 in.
Length 22 ft. 2 in.
Seats 1
Empty Weight 1,650 lbs.
Gross Weight 2,470 lbs.
Engine Curtiss D-12 Challenger, 485 hp
Top Speed 325 mph
Cruise Speed 250 mph
Stall Speed 85 mph