 The helicopter most closely associated with long-range U.S. air-sea rescue operations in Southeast Asia was the Sikorsky S-61R, called the "Pelican" or "Jolly Green Giant", a variation of the SH-3 Sea King.First acquired by the U.S. Navy in 1961 for anti-submarine warfare, variants of the helicopter were quickly utilized for many duties including rescue, and were operated as well by the United States Air Force (USAF) which developed an in-flight refueling system.In 1970, USAF Air Rescue and Recovery Service (ARRS) Sea Kings flew from the U.S. to France using such refueling methods.