Helicopter 66 pictured during the Apollo 10 recovery in 1969
Helicopter 66 was a Sikorsky Sea King SH-3D. The SH-3D model Sea Kings were designed for anti-submarine warfare (ASW) and were typically configured to carry a crew of four and up to three passengers. Powered by two General Electric T58-GE-10 turboshaft engines producing up to 1,400 horsepower (1,000 kW) each, SH-3Ds had a maximum airspeed of 120 knots (220 km/h; 140 mph) and a mission endurance averaging 4.5 hours. They had a maximum allowable weight of 20,500 pounds (9,300 kg) with the ability to carry an external payload of up to 6,000 pounds (2,700 kg).
During ASW missions, the Sea King SH-3D was typically armed with MK-46/44 torpedoes.