General Electric GE38

The GE27 was developed in the early 1980s under the "Modern Technology Demonstrator Engines" (MTDE) program sponsored by the United States Army Aviation Applied Technology Directorate.^[2] Sporting a 22:1 pressure ratio, which was a record for single-spool compressors at the time, the GE27^[3] was GE's unsuccessful submission to power the Bell Boeing V-22 Osprey tiltrotor aircraft. The GE27 also had a compressor air flow of 27–28 pounds per second (12–13 kg/s) and a turbine temperature of 2,400–2,500 °F (1,320–1,370 °C; 2,860–2,960 °R; 1,590–1,640 K).^[2] The GE27 first ran in late 1984, but it unexpectedly lost the V-22 engine competition to the Allison 501-M80C, which was not a participant in the MTDE program.^[4]

In the late 1980s, GE used the GE27 as the basis for the commercial development of turboshafts, turboprops, turbofans, and propfans under the GE38 name. GE formed a 50/50 venture with Garrett (then a division of AlliedSignal) to develop the turbofan variant^[5] called the CFE (Commercial Fan Engines) CFE738, which used the GE27's gas generator core.^[2] One of a range of advertised GE38 unducted fan (UDF) sizes,^[5] the 9,620 lbf (4,360 kgf; 42.8 kN) takeoff thrust GE38-B5 was for a time the baseline engine for the West German-Chinese MPC 75 regional airliner.^[6] The GE38 became the T407 military turboprop in partnership with Lycoming Engines for the Lockheed P-7A, with a maximum takeoff power of 6,000 shp (4,475 kW). First run on December 26, 1989,^[7] the T407 engine was scheduled to undergo flight testing on a Lockheed P-3 Orion testbed aircraft in the summer of 1990,^[8] but the US Navy canceled Lockheed's P-7 contract on July 20, 1990.^[9] The commercial version of the T407 was the GLC38 (General Electric/Lycoming Commercial 38), which was unsuccessfully offered for several turboprop airliners in the late 1980s and early 1990s.^[2]

The new T408 (GE38-1B) is slated to power the new Sikorsky CH-53K King Stallion three-engined helicopter for the US Marine Corps. It has a power rating of 7,500 shp.^[10] The GE38 completed its first round of ground testing in May 2010.^[11] Two test engines have completed over 1,000 hours of ground testing by November 2011. Five test engines will be used in the 5,000-hour test program.^[12] In September 2019, GE delivered the first production T408 engine to the U.S. Naval Air Systems Command (NAVAIR) for the CH-53K.^[13] GE also offered the engine to power the U.S. Navy's Ship-to-Shore Connector air-cushioned landing craft.

The T408 was also tested by the U.S. Army and Boeing as an alternative powerplant on an NCH-47D Chinook testbed helicopter. The helicopter configuration was ground tested beginning in late 2019, followed by an initial flight on September 22, 2020.^[14] Conclusion of the test trials was announced on May 12, 2021.^[15]

T407-GE-400

• Lockheed P-7

T408-GE-400 (GE38-1B)

• Boeing NCH-47D Chinook (flying testbed)^[16]
• Sikorsky CH-53K King Stallion

CFE CFE738

Turbofan variant of the T407-GE-400, used on the Dassault Falcon

CPX38

Proposed turboprop engine variant of the GE38-1B^[17]

GE38-3

An 8,000 shp (6,000 kW) class derivative engine under consideration by the U.S. military in 2006^[18]

GE38-B5

A contra-rotating, ungeared, unducted fan (UDF) derivative with a bare engine weight (including the UDF) of 2,395 lb (1,086 kg), a UDF diameter of 85 inches (2.1 meters), and a blade count of 11 on one propeller and 9 on the other; provides a takeoff thrust of 9,644 lbf (4,374 kgf; 42.90 kN) with a thrust-specific fuel consumption (TSFC) of 0.240 lb/(lbf⋅h) (6.8 g/(kN⋅s)), and a cruise thrust of 2,190 lbf (990 kgf; 9.7 kN) with a TSFC of 0.519 lb/(lbf⋅h) (14.7 g/(kN⋅s)); proposed for the MPC 75 German-Chinese regional airliner in the late 1980s^[6]

GLC38

Proposed turboprop variant of the T407-GE-400

• Boeing NCH-47D Chinook (flying testbed)
• Sikorsky CH-53K King Stallion

Data from GE Aviation.^[19]

Related development

• CFE CFE738
• General Electric GE36

Comparable engines

• Allison T406
• Honeywell T55
• Pratt & Whitney PW150

Related lists

• List of aircraft engines