Sikorsky S-61

The Sikorsky S-61L and S-61N are civil variants of the SH-3 Sea King military helicopter. They were developed and produced by the American helicopter manufacturer Sikorsky Aircraft.

The commercial version of the Sea King was developed during the late 1950s. Two versions, the land-based S-61L and the amphibious S-61N, were created. The S-61L had an enlarged cabin and dispensed with some amphibious features, such as its float stabilizers, for greater payload capacity. It was considered attractive to utility operators, while the amphibious S-61N appealed to offshore operators. The first models were delivered to customers in September 1961. By the turn of the century, they had become two of the most widely used airliners and oil rig support helicopters built.

Airliners were a key customer for the S-61L. Los Angeles Airways, New York Airways, and Chicago Helicopter Airways were among the first operators. However, operations in this sector proved troublesome, with profits elusive and service often subject to noise complaints and accidents. S-61s also saw service in various search and rescue (SAR) sectors. Third-party companies have often converted individual airframes by shortening the fuselage to bolster their lift capacity. Governmental organizations have procured the S-61: the United States Department of State was a prominent operator of the type into the twenty-first century.