The utility helicopter LZ-5 utilised Doman's unorthodox gimbal mounted, rotor head system with no need for flap and drag hinges dampers. The type did not go into production and only three prototypes were built, the first two of which were purchased by the US Army, as the YH-31, but ultimately rejected as the rotor system was deemed too complex for practical field repair. The third prototype flew extensively in Canada as CF-IBG and in the US, France (Paris Air Show in 1960) and Italy with the registration N812, and is now on display at this super museum.