The Type 192 Belvedere was a tandem cargo helicopter made by the British Bristol Aeroplane Company. It first took flight in 1958 and was officially introduced in 1961.
The Belvedere helicopters were first designed for use in the Royal Navy, but the naval variant was cancelled. Later, they were modified to carry 18 fully-equipped troops into battle with a total load capacity of 6 000 pounds or about 2 700 kilograms.
Apart from troop transport, the Belvedere could also be used to drop supplies or evacuate casualties.
Some features from the original naval designs made it into the Type 192. These were a bit of a disadvantage for its application as a troop transport.
For example, the tall front undercarriage was meant to accommodate torpedoes and, as a result, passengers had to manage a 1.2m drop to the ground.
In addition, the engines were mounted on the ends of the cabin. Compared to the highly-successful Chinook CH-47 which had them on the flanks, making a versatile rear loading-ramp possible.
This design also meant that access to the cabin required a small gangway, which caused a bulge on the port side of the craft.
The first prototype used tandem wooden-blade rotors and a completely manual control system. The undercarriage was a quadricycle design that was fixed and incorporated castors.
Later prototypes used all-metal blades and had controls which allowed night flights. Another interesting fact is that the prototypes had an upwards hinged door, but the downwash of the rotors would slam it shut, so production models used a sliding door design.
To prevent the rotors from colliding, they were mechanically synchronized using a shaft. An advantage of this is that one of the twin engines could drive both rotors in the case of engine failure. The engines could also run at double power in an emergency.
The Type 192 was in service with the RAF from 1961 to 1969. In total 26 were built and entered service. A civilian model, the 192C, was attempted but the public showed no interest.