The front undercarriage was unusually tall, originally designed to give adequate clearance for loading torpedoes underneath the fuselage in the anti-submarine warfare role.

(By comparison the contemporary purpose-designed troop transport Boeing Vertol CH-46 Sea Knight had its engines above the aft cabin to permit a rear loading ramp).

To provide access to the cabin from the cockpit there was a small entry past the engine that resulted in a bulge on the left side of the fuselage.

[1][3] 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.

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.

They were originally designed for use with the Royal Navy but were later adapted to carry 18 fully equipped troops with a total load capacity of 6,000 lb (2,700 kg).

The two rotors were synchronised through a shaft to prevent blade collision, allowing the aircraft to operate through only one engine in the event of an emergency.

[5] To demonstrate the aircraft's potential, Bristol chief test pilot Charles "Sox" Hosegood set the London–Paris and Paris–London speed records in May 1961 in a Belvedere.