The Wittman W-5 Buttercup is a two place aircraft designed and built by Steve Wittman in 1938. Designated as the Buttercup Model W, the original aircraft is housed in the Experimental Aircraft Association, EAA AirVenture Museum in Oshkosh, WI. The Buttercup was considered as the basis for a four place certified production model by Fairchild Aircraft. Fairchild executives were impressed with the aircraft that chance landed at their factory airport in Hagerstown, Maryland. Wittman sold production rights, but Fairchild did not pursue the effort due to wartime production obligations.