Towards the end of 1943, Frank Nicholas Piasecki also appeared on the scene. Piasecki had worked for the Kellett Autogyro Company and Budd Aircraft. He had previously been involved in development of the Platt-LePage XR-1 and had undertaken a small-scale project of his own. Frank N. Piasecki, President of the PV-Engineering Forum, an organization he formed with F.M.Vinsie and Elliott Daland for the purpose of building his helicopter. Records show he is the first American to be granted a license to fly a helicopter before first qualifying to fly a conventional airplane. He did, however, previous to flying his own helicopter design, get in some flying time in a light plane. This helped him, too, in building the PV.
Built prototype of PiAC 16H-1C Pathfinder compound helicopter in 1962, continuing development under a U.S. Navy contract, but no production. Work included developing vectorod-thrust ducted propeller system for attack helicopters under U.S Army contract, definition of a possible U.S. Marine Corps medium-lift replacement type, and marketing the PZL Swidnik W-3A in the Americas and Pacific Rim regions.
In 1956 the company became Vertol Aircraft Corporation.