The T58 turboshaft engine -- the engine that would power the United States' first jet helicopter, the engine that would power the Sikorsky Sea King helicopter that recovered the Apollo astronauts, and the engine that still powers Marine One, the helicopter of the U.S. president since the Kennedy administration -- was born in 1953 with the award of a $3 million contract from the U.S. Navy. Under the terms of the contract, GE was to develop the XT-58 "baby gas turbine" that the company had proposed as a powerplant for helicopters. The engine was to weigh 400 pounds and was to produce 800 shaft horsepower (shp).

Subsequently, more generous contracts enabled extensive engine redesign and the use of new, lighter-weight alloys. As a result, engine weight was reduced to 250 pounds and power output was increased to 1,050 shp by 1957 -- the year two T58s replaced a piston engine in a Sikorsky HSS-1F helicopter for the historic flight of the first U.S. turbine-powered helicopter. Recognizing the potential of this breakthrough, Sikorsky shortly produced the HSS-2 (the S-61 in commercial applications) specifically for the T58.

Within the year, Kaman followed with the T58-powered SH-2 utility helicopter for the U.S. Navy, Sikorsky produced the S-62, which entered service with the U.S. Coast Guard, and later with commercial carriers and cargo operators, and Piasecki Helicopter (later Boeing) produced the UH-21D for the U.S. Army.

In 1959, the U.S. Federal Aviation Administration awarded certification for the first time time to a helicopter turboshaft engine -- the CT58, a civil version of the T58. That same year, GE began adaptation of the T58 to produce the LM100 gas turbine/gas generator for marine and industrial applications.

By 1984, when GE ceased production of the T58 and the CT58, more than 6,300 engines were in service on helicopters throughout the world.

In addition, still more T58 engines have been produced under license in Japan, Italy and the United Kingdom.

Most recently, in 2002, the U.S. Navy approved conversion of 300 T58-GE-16 engines powering Boeing CH-46E helicopters of the U.S. Marine Corps to the T58-GE-16A configuration. The conversion, proposed in GE's Engine Reliability Improvement Program, increases engine time on wing through installation of an improved engine core (high-pressure compressor, combustor, and high-pressure turbine) and modifications to the power turbine and accessory package.