General Electric T700

CT7 / T-700 shown at the 2007 Paris Air Show

The engines T700 and CT7 belong to a family of turboshaft and turboprop - engines of company General Electric in the class from 1100 to 1850 kW. They are used to power a large number of helicopters and smaller commercial aircraft.

development

In 1967 General Electric began to work on a demonstrator (the GE12) for a new shaft turbine. The reason was the US Army's interest in a next-generation transport helicopter. The Army order led to the development of the Sikorsky S-70 Black Hawk , which was powered by two GE-T700 turbines (the series version of the GE12). The T700 was tested from 1973, registered in 1976 and went into production in 1978.

Its first version, the T700-GE-700 , is a shaft turbine with a five-stage axial and a single-stage radial compressor, which are driven by a two-stage turbine. The axial compressor stages are designed as blisk . The inlet guide vanes and the first two stator stages are adjustable. The ring-shaped combustion chamber with central fuel injection ensures good fuel combustion and low smoke development. The output shaft is driven by a two-stage turbine. The drive was designed for high reliability. A filter is used at the air inlet to separate dirt, sand and dust. The T700-GE-700 is approved for an output of 1210 kW.

The T700-GE-700 was followed by improved and more powerful engine variants, which were used on the military helicopters UH-60 Black Hawk / SH-60 Seahawk, AH-64 Apache, Kaman SH-2G Super Seasprite and Bell AH-1W Supercobra. They also serve as a drive for some versions of the AgustaWestland EH101 and the NH90.

The civil version of the T700 is the CT7 , which has been in use since 1984 . It is used on the Bell 214ST (an improved version of the Huey), civil Black Hawks, and the Sikorsky S-92 (a derivative of the Black Hawk), all of which are two-turbine models. The CT7-8 for the S-92 has a maximum take-off power of 1879 kW, a length of 1.24 m and a weight of 243 kg.

There are also turbo- prop versions of the CT7 that are equipped with a reduction gear to drive the propeller. They are used in smaller twin-engine airliners such as the Swedish SAAB 340, the Indonesian-Spanish Airtech CN-235 Cargolifter and the Czech Let L-610G. The basic version CT7-5A delivers 1294 kW starting power. The CT7-6 corresponds to the military version T700-T6A1.

The following variant YT706 (also called CT7-8B5 or T706-GE-700 ) is based on the CT7-8A engine, which was approved by the FAA in 2002. Compared to the T700, the YT706 has a larger compressor, an improved engine core and a FADEC . It offers up to 30 percent more power than the current T700-701C and improves the capabilities of the MH-60M Black Hawk, which is used by the US Army for special operations, for use in areas with special climatic requirements (hot and high missions). The CT-8C and CT-8E are improved versions with a revised high pressure turbine and with a new three-stage low pressure turbine for the H-92 and EH101.

commitment

T700

• AH-1W / Z Supercobra T700-401C
• SH-2G Super Seasprite T700-401C
• UH-1Y Venom T700-401C
• AH-64 Apache T700-701C, T700-701D
• UH-60 Black Hawk T700-701C, T700-701D (UH-60L)
• SH-60 Seahawk T700-401C
• HH-60 Jayhawk T700-401C
• MH-60 G / K T700-701C, T700-701D
• CH-148 Cyclone
• AgustaWestland EH101 / CH-149 Cormorant / VH-71 Kestrel T700-T6A1, T700-T6A1, CT7-6 / -6A
• NH90 T700-T6E / T6E1
• Piasecki X-49

CT7

• AgustaWestland AW149
• AgustaWestland AW189
• Bell 214ST CT7-2
• Sikorsky S-70C CT7-2, CT7-2D
• Sikorsky S-92 CT7-8
• Sikorsky H-92 Superhawk CT7-8C

CT7 turboprop

• CASA / IPTN CN-235 CT7
• Saab 340 CT7
• Sukhoi Su-80 CT7

Technical specifications

The shaft turbine has a six-stage compressor (five stages axial, one stage radial), an annular combustion chamber and a two-stage high-pressure and low-pressure / power turbine.

Engine	Dry weight in kg	compression ratio	Starting power	Continuous output	Height in mm	Width in mm	length in mm
T700-GE-700/701	198	17: 1		1193 WPS	635	635	1193
T6A	243	17: 1		1750 WPS	660	660	1224
CT7-5A2	355.2		1294 kW	1193 kW	737	660	2438
CT7-8	243.6		1879 kW	1523 kW	636	660	1293
CT7-9B	365.1		1305 kW	1305 kW	737	660	2438

Web links

Commons : General Electric T700  - Collection of Pictures, Videos and Audio Files

• General Electric T700 page on the GE Aviation corporate website
• Data sheet at Turbokart (English)
• Datasheet at Deagel (English)

swell

1. ↑ General Electric T700 (Janes Defense)
2. ↑ AVIATION: Jet Engines
3. ↑ ^{a b c} EASA.IM.E.010. (pdf) easa.europa.eu, accessed on February 28, 2015 (English).