In 1956, Gyrodyne entered the competition to produce a single seat "personal" helicopter for operation off destroyer heli-decks for fleet observation, and for battlefield support, and built ten examples of the XRON-1 for the U.S. Navy. These also had a coaxial rotor layout and a 40hp Nelson H.59 engine - later replaced by a 60hp Porsche. This experiment led to development of the QH-50 unmanned drone versions of the XRON-1 and Gyrodyne delivered over 60 production QH-50Cs for operation from Naval frigates.
R.Simpson "Airlife's Helicopter and Rotorcraft", 1998
Technical data for QH-50C
Engine: 1 x T50-BO8A turboshaft, rated at 243kW, rotor diameter: 6m, take-off weight: 1036kg, empty weight: 524kg, max speed: 148km/h, ceiling: 5000m, range: 132km, armament: 2 x Mk-44 torpedos or 1 x Mk-46 torpedo