 Umbaugh had by this time concluded an agreement for Fairchild Engine and Airplane Corporation to undertake final development and mass production of the U-18 as the “Flymobil.”

Fairchild built five development gyroplanes during 1960, one of which was used to gain FAA Approved Type Certificate 1H17 in September 1961.Umbaugh established a large network of dealers and distributors in the United States, upon whom he imposed minimum sales quotas to generate a large order backlog, but he experienced difficulty filling the orders due to inadequate manufacturing capability at Fairchild.Under pressure from the dealers, Umbaugh Aircraft Corporation ceased operations in 1962 and the agreement with Fairchild was terminated.