Glidden S. Doman formed Doman Helicopters, Danbury, Connecticut, 31 August 1945, to develop helicopter with hingeless blades and enclosed self-lubricating hub. Rotor tested on Sikorsky R-6, led to various prototypes ending with 8-seat D-10B (Lycoming piston engine flat-rated at 400 hp) September 1958. Plans to produce in series in Italy and Puerto Rico came to nothing, as did twin-turbine BD-19 (Berlin Doman) project of 1967-70.