Sylvester "Steve" Wittman built two types of airplanes: Racing machines and Travel machines. The ancestors of these two blood lines were Chief Oshkosh and Buttercup. The Buttercup was built as a utility hauler, and there was only one made - in 1937. He flew it all over the western hemisphere, from Alaska to Bermuda, Florida to Oregon. The Buttercup almost made it into production (cancelled due to WWII) coming to the interest of Fairchild as a four-place project, called the 'Big X.' One plane was built for them by "Witt" - a 4-place, 6 cylinder, 130 HP Franklin powered prototype.
The real genius of the Buttercup design is Wittman's claim of 38-40 mph (indicated) slow-flight speed and a near 150 mph top speed, and all on 85 hp! The high speed is vintage Wittman, the low speed is due to an ingenius flap-coupled, retracting lead edge design (seen in today's airliners). Earl Luce of LuceAir, Inc. has 'revived' the Buttercup, featured in the April 2003 issue of Sport Aviation. Kits and fabricated assemblies for the Buttercup are available from Aircraft Spruce.