Sikorsky UH-34D Seahorse
Navy BuNo 147174

Sikorsky UH-19 Chickasaw being launched from the USS Boxer LPH-4

The Sikorsky H-34 Choctaw (also known as the Sikorsky S-58) was a helicopter originally designed for the US Navy for service in the anti-submarine warfare (ASW) role. It was developed from the Sikorsky UH-19 Chickasaw. It is a utility transport helicopter, with no armament on board.

It was powered by a single Wright R-1820-84 radial engine, and could carry 12 to 16 troops or eight stretcher cases if utilized in the MedEvac role.

The aircraft first flew on March 8, 1954. It was initially designated HSS Seabat by the Navy and HUS Seahorse by the US Marines. In 1962 all services adopted the US Army designation, H-34 Choctaw. In 1962 under the new unified system, the Seabat was redesignated SH-34, the Seahorse as the UH-34, and the Choctaw as the CH-34.

US production ceased in 1970 with 1,800 built.

It was also built and developed under license from 1958 in the United Kingdom by Westland Aircraft as the turbine engined Wessex. The Wessex was fitted out with weapons for ASW use.