Twenty-six Belvederes were built, entering service as the Belvedere HC Mark 1. The Belvederes 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. In that case, the remaining engine would automatically run up to double power to compensate.