TheGeneral Electric T58 is an Americanturboshaft engine developed for helicopter use. First run in 1955, it remained in production until 1984, by which time some 6,300 units had been built. On July 1, 1959, it became the first turbine engine to gain FAA certification for civil helicopter use. The engine was license-built and further developed byde Havilland in the UK as theGnome, in theWest Germany byKlöckner-Humboldt-Deutz,[1] and also manufactured byAlfa Romeo and theIHI Corporation.
Development commenced with a 1953US Navy requirement for a helicopter turboshaft to weigh under 400 lb (180 kg) while delivering 800 hp (600 kW). The engine General Electric eventually built weighed only 250 lb (110 kg) and delivered 1,050 hp (780 kW) and was soon ordered into production. First flight was on a modifiedSikorsky HSS-1 in 1957, and civil certification for theCT58-100 variant was obtained two years later.[2]
A number of unusual features are incorporated into the T58:[3]
an all-axial compressor. Most other turboshafts in this power bracket have a centrifugal unit as a final compressor stage. As a result, the blades at the rear of the compressor are very small (less than 0.5in high) and extremely thin.
compressor handling at part speed is facilitated by several rows of variable pitch stators at the front part of the unit. This was a fairly novel feature when the engine was first introduced.
a single stage power turbine. which delivers power to the rear of the engine. The hot exhaust stream is diverted sideways, away from the output shaft.
the combustor is a straight-through annular design, rather than reverse flow.
The main production version of the engine was theT58-GE-10, developing 1,400 hp (1,044 kW). The most powerful version, the T58-GE-16, produces 1,870 hp (1,390 kW).[4]
Two T58s, converted to turbojets by the removal of the power turbines, were used as the engines on theMaverick TwinJet 1200.[6]
TheCarroll Shelby turbine cars entered in the 1968 Indianapolis 500 race were powered by T58s.[7] The cars were found to be using variable inlets to get around the USAC regulations on the maximum allowable inlet size and were disqualified.
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