The General Electric T700 and CT7 are a family of

turboshaft A turboshaft engine is a form of gas turbine that is optimized to produce shaft horsepower rather than jet thrust. In concept, turboshaft engines are very similar to turbojets, with additional turbine expansion to extract heat energy from the ex ...

and

turboprop A turboprop is a Gas turbine, gas turbine engine that drives an aircraft Propeller (aeronautics), propeller. A turboprop consists of an intake, reduction drive, reduction gearbox, gas compressor, compressor, combustor, turbine, and a propellin ...

engines in the class.

Design and development

In 1967, General Electric began work on a new turboshaft engine demonstrator designated the "GE12" in response to US Army interest in a next-generation utility helicopter. The GE12 was designed and conceived by GE's Art Adamson and Art Adinolfi. In 1967, both GE and Pratt & Whitney were awarded contracts to work parallel with each other to design, fabricate, and test the technology. The Army effort led, in the 1970s, to development of the

Sikorsky S-70 The Sikorsky S-70 is an American medium transport/utility helicopter family manufactured by Sikorsky Aircraft. It was developed for the United States Army in the 1970s, winning a competition to be designated the Sikorsky UH-60 Black Hawk, UH-60 ...

Black Hawk, powered by twin GE "T700" turboshafts, the production descendant of the GE12. The T700 was initially bench-tested in 1973, passed military qualification in 1976, and went into production in 1978. The initial "T700-GE-700" is an ungeared

free-turbine turboshaft A free-turbine turboshaft is a form of turboshaft or turboprop gas turbine engine where the power is extracted from the exhaust stream of a gas turbine by an independent turbine, downstream of the gas turbine. The power turbine is not mechanicall ...

, with a five-stage axial / one-stage centrifugal mixed-flow compressor, featuring one-piece " blisk" axial stages, with the inlet guide vanes and first two stator stages variable; an annular combustion chamber with central fuel injection to improve combustion and reduce smoke; a two-stage compressor turbine; and a two-stage free power turbine with tip-shrouded blades. The engine is designed for high reliability, featuring an inlet particle separator designed to spin out dirt, sand, and dust. The T700-GE-700 is rated at 1,622 shp (1,210 kW) intermediate power. The T700-GE-700 was followed by improved and uprated Army engine variants for the

UH-60 Black Hawk The Sikorsky UH-60 Black Hawk is a four-blade, twin-engine, medium-lift military utility helicopter manufactured by Sikorsky Aircraft. Sikorsky submitted a design for the United States Army's Utility Tactical Transport Aircraft System (UTTAS) ...

and the

AH-64 Apache The Hughes/McDonnell Douglas/Boeing AH-64 Apache ( ) is an American twin-turboshaft attack helicopter with a tailwheel-type landing gear and a tandem cockpit for a crew of two. Nose-mounted sensors help acquire targets and provide night vis ...

helicopters, as well as marinized naval engine variants for the SH-60 Seahawk derivative of the Black Hawk, the SH-2G Seasprite, and the Bell AH-1W Supercobra. T700s are also used on Italian and commercial variants of the AgustaWestland EH101/AW101 helicopter, and Italian variants of the

NHIndustries NH90 The NHIndustries NH90 is a European medium-sized, twin-engine, multirole military helicopter. It was the first production helicopter to feature entirely fly-by-wire flight controls.Perry, Dominic"Rotor club: Our top 10 most influential helicop ...

helicopter. These are all twin-engine machines, except for the three-engined EH101. The commercial version of the T700 is the "CT7", with the engine used on the Bell 214ST (an enlarged version of the Huey), commercial Black Hawks, and the

Sikorsky S-92 The Sikorsky S-92 is an American twin-engine medium-lift helicopter built by Sikorsky Aircraft for the civil and military helicopter markets. The S-92 was developed from the Sikorsky S-70 helicopter and has similar parts such as flight control ...

derivative of the Black Hawk, all of which are twin-engine helicopters. The CT7 turboprop variants use the same core as the turboshaft variants, with a propeller gearbox fitted forward of the core. CT7 turboprops are used on variants of the Swedish

Saab 340 The Saab 340 is a Swedish twin-engine turboprop aircraft designed and initially produced by Saab AB and Fairchild Aircraft. It is designed to seat 30–36 passengers and, as of July 2018, there were 240 operational aircraft used by 34 differen ...

airliner, the Indonesian-Spanish Airtech CN-235 cargolifter, and the Czech Let L-610G airliner, all twin-turboprop aircraft. The baseline CT7-5A provides 1,735 shp (1,294 kW) on takeoff. In the late 1980s, GE also proposed a much larger turboprop, the T407/GLC38, with a five-stage axial/one-stage centrifugal mixed-flow compressor, an annular combustor with 15 burners; a two-stage compressor turbine, a three-stage power turbine, and max takeoff power of 6,000 shp (4,475 kW). The YT706 engine is based on the CT7-8A engine. Compared with the H-60's primary T700 engine, the T706 has a larger compressor, hot section improvements, and full authority digital engine control. The T706 is rated at 2,600 shp (1,939 kW) and increases the hot-and-high mission capability of the U.S. Army's MH-60M Black Hawk for Special Operations applications."Sikorsky S-70A."
(online subscription article) ''Jane's All the World's Aircraft'', 25 May 2016.

Variants

T700: Military turboshaft engine. *YT700: Prototype version. *T700-GE-700: Initial T700 variant. *T700-GE-701: The improved T700-GE-701A, -701B, -701C,-701D versions have also been developed from the original -700. *T700-GE-401: Navalised version for SH-60 Seahawk helicopters. *T700-GE-401C: Universal application version of the -401. *T700-GE-701C: Universal application version of the -701. *T700-TEI-701D: Licensed produced version of

Tusaş Engine Industries Tusaş Engine Industries (TEI; ) is an aerospace engine manufacturer and a design center for the production of engines and engine parts for commercial and military aircraft. It is based in Eskişehir, Turkey. TEI was founded in 1985 as a joint ...

Turkey Turkey, officially the Republic of Türkiye, is a country mainly located in Anatolia in West Asia, with a relatively small part called East Thrace in Southeast Europe. It borders the Black Sea to the north; Georgia (country), Georgia, Armen ...

. Developed for use in the Sikorsky/Turkish Aerospace Industries T-70 utility helicopter. *T700-701K: First rear-drive version of the T700 family, a product from the joint development with Samsung Techwin (later became Hanwha Aerospace). Powering the KAI KUH-1 Surion with Hanwha's licensed production. CT7 turboshaft: Commercial version of T700. *CT7-2A: Basic model *CT7-2D: Higher flow compressor and surface coatings to improve resistance to wear and corrosion *CT7-2D1: Similar to the CT7-2D but uses a CT7-6 type hot section *CT7-2E1: Leonardo Helicopters AW189 *CT7-6/-6A: The CT7-6/-6A turboshaft engines are upgraded commercial variants of the successful T700/CT7 engine family. The turboshaft engine powers the entire development fleet of

AgustaWestland AW101 The AgustaWestland AW101 is a medium-lift helicopter in military and civil use. First flown in 1987, it was developed by a joint venture between Westland Helicopters in the United Kingdom and Agusta in Italy in response to national requiremen ...

helicopters with thousands of flight hours of operation. *CT7-8: The CT7-8 is a family of powerful engines in the 2,500 to 3,000 shp class. They are more powerful and more efficient versions of its predecessors. *CT7-8A: A version of the CT7-8 family used to power older Sikorsky S-92/H-92 helicopters. *CT7-8A1: A more fuel efficient version of the CT7-8A. It is used to power newer Sikorsky S-92/H-92 helicopters. The CT7-8A1 produces 2,520 shp. *CT7-8A5 *CT7-8A7: Developed by GE as an uprated, more efficient and more reliable version of the CT7-8A1 engine for the

Royal Canadian Air Force The Royal Canadian Air Force (RCAF; ) is the air and space force of Canada. Its role is to "provide the Canadian Forces with relevant, responsive and effective airpower". The RCAF is one of three environmental commands within the unified Can ...

's Sikorsky CH-148 Cyclone helicopters. It is the most modern version of the CT7/T700 engine family. The CT7-8A7 produces 3,000 shp. *CT7-8B *CT7-8B5 *CT7-8E *CT7-8E5 *CT7-8E6 *CT7-8F *CT7-8F5 CT7 turboprop: Turboprop version of CT7. *CT7-3: Compact shortened and lightened version. *CT7-5A2 *CT7-5A3 *CT7-7A *CT7-7A1 *CT7-9B *CT7-9B1 *CT7-9B2 *CT7-9C *CT7-9C3 *CT7-9D *CT7-9D2

Applications

T700/CT7 turboshaft

AgustaWestland CH-149 Cormorant The AgustaWestland CH-149 Cormorant is the air-sea rescue variant of the AgustaWestland AW101 (formerly EH101) helicopter for the Canadian Armed Forces. Developed by AgustaWestland in Italy (now merged as part of Leonardo), the CH-149 is a m ...

Lockheed Martin VH-71 Kestrel The Lockheed Martin VH-71 Kestrel was a variant of the AgustaWestland AW101 (formerly the EH101) that was being manufactured to replace the United States Marine Corps' Marine One U.S. Presidential transport fleet. Originally marketed for var ...

* AgustaWestland AW149 *

AgustaWestland AW189 The AgustaWestland AW189 is a twin-engined, super-medium-lift helicopter manufactured by Leonardo S.p.A. It is derived from the AW149, and shares similarities with the AW139 and AW169. Development On 20 June 2011, development of the eight-t ...

* Bell 214ST * Bell 525 * Bell AH-1W SuperCobra * Bell AH-1Z Viper *

Bell UH-1Y Venom The Bell UH-1Y Venom (also called Super Huey) is a twin-engine, 4-blade, medium-sized utility helicopter built by Bell Helicopter under the H-1 upgrade program of the United States Marine Corps. One of the latest members of the numerous Bell H ...

Boeing AH-64 Apache The Hughes/McDonnell Douglas/Boeing AH-64 Apache ( ) is an American twin-turboshaft attack helicopter with a tailwheel-type landing gear and a tandem cockpit for a crew of two. Nose-mounted sensors help target acquisition, acquire targets an ...

* KAI KUH-1 Surion *

Kaman SH-2G Super Seasprite The Kaman SH-2G Super Seasprite is an American ship-based helicopter with Anti-submarine warfare, anti-submarine, Anti-Surface Warfare, anti-surface threat capability, including over-the-horizon targeting. This aircraft extends and increases ship ...

* Kamov Ka-64 Sky Horse * Leonardo Helicopters AW249 *

* Sikorsky S-70/H-60 series **

Mitsubishi H-60 The Mitsubishi H-60 series is a twin-turboshaft engine helicopter based on the Sikorsky UH-60 Black Hawk, Sikorsky UH-60 helicopter family for use by the Japan Self-Defense Forces (JSDF). The SH-60J/K/L are Anti-submarine warfare, anti-submarin ...

** Piasecki X-49 ** Sikorsky HH-60 Jayhawk ** Sikorsky HH-60 Pave Hawk ** Sikorsky SH-60 Seahawk **

Sikorsky UH-60 Black Hawk The Sikorsky UH-60 Black Hawk is a four-blade, twin-engine, medium-lift military utility helicopter manufactured by Sikorsky Aircraft. Sikorsky submitted a design for the United States Army's Utility Tactical Transport Aircraft System (UTTAS ...

** Sikorsky CH-148 Cyclone