Having employed designer Grover Loening as a consultant and helicopter enthusiast Frank Piasecki employed as a junior engineer,Charnov 2003, pp.183. Platt-Lepage set to work developing the helicopter, using a similar rotor arrangement to that of the Fa 61.McGowen 2005, p.19. The aircraft, designated XR-1, flew three months behind schedule in 1941.Francillon 1990, p.50.
