Sikorsky HH-52A “Seaguard” (1963)

Sikorsky HH-52A “Seaguard” The Sikorsky HH-52A helicopter was developed from a Sikorsky commercial S-62 amphibious helicopter. The S–62 had features that were desired by the Coast Guard. It floated on an amphibious hull, it was turbine powered, had a large main cabin and it was built utilizing proven components..The automatic stabilization system used on the S-62 was a scaled version of the larger S-61 (SH-3). The rotor system came from the S-55 (HO4S), as did most of the drive system which had already proven to be reliable. The assembly was design limited to 730 shaft horsepower. Small jet engines suitable for helicopters were rare and not available at the time.  Sikorsky solved the problem by using a 1230 SHP General Electric T-58-GE-8B engine and derating it. With the extra 500 HP worth of air capacity on the front end density altitude was not an operational problem. A Coast Guard Evaluation Program confirmed the contractor claims for performance and suitability to fill the [...]