The first Type 192 prototype "XG447" flew on 5 July 1958 with tandem wooden rotor blades, a completely manual control system and a castored, fixed quadricycle undercarriage. From the fifth prototype, the rotors fitted were all-metal, four-bladed units. Production model controls and instruments allowed night operations. The prototype machines had an upwards-hinged main passenger and cockpit door, which was prone to being slammed shut by the downwash from the rotors. This was replaced by a sliding door on the later aircraft.