Vanguard Omniplane
Two previous Piasecki Helicopter Corporation’s made their own company called Vanguard Air and Marine Corporation in 1959. They wanted to design an executive VTOL aircraft and came up with the Vanguard Omniplane. The ducts on the plane included vertical thrust propellers. Someone could close them thanks to venetian blind shutters to create a forward flight. They began ground tests and NASA wind tunnel tests in 1959. Hover tests started in 1961, but mechanical issues plagued the Omniplane, and Vanguard canceled the project early the following year.