Designed and built a single-place aircraft with a 14-horsepower Harley-Davidson engine at age 20.
Moved to Oshkosh in 1931 to run his own flying service and manage the Winnebago County Airport.
Built his second racer, named Bonzo, and won second place in the 1935 Thompson Trophy Race.
Designed a single-leaf, spring-steel landing gear which major companies adopted.
Ran a flight school for the Civil Pilot Training Program from 1940 to 1943, where some 700 pilots were provided nearly 24,000 hours of flight instruction.
Designed and built the W-8 Tailwindin 1953, later selling it in kit form to thousands.
Joined the Experimental Aircraft Association, as Member Number 38, in 1953 and convinced EAA founder Paul Poberezny (enshrined 1999) to hold the 1956 EAA Fly-In at his Oshkosh Airport, setting a course for future EAA conventions.
Built his final race plane, Witt’s V, in 1970 to compete in the Formula V Class. He became its first National Champion, and continued to win or place in every Formula V race through 1981, when he finally retired from racing.
Came out of retirement at age 85 for one last race at the Daytona Skyfest where he placed third.