 The Avrocar was proposed to the U.S. Army as a type of "flying Jeep" that could also serve as a proof-of-concept test vehicle for a later supersonic flying saucer designs, PV-704 and Weapon System 606A.Two Avrocars were built, one for wind-tunnel testing at NASA Ames and the other for flight testing.The designs were underpowered and only operated in a ground-cushion effect, much like a hovercraft.