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General Electric CF6

General Electric Aviation · Aircraft Engine · USA · Cold War (1970–1991)

General Electric CF6 — Aircraft Engine
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The General Electric CF6 is a family of high-bypass turbofan engines produced by GE Aerospace from 1971 onward. Spanning a thrust range of 41,500 to 72,000 lbf, the CF6 powered the first generation of widebody airliners and a long line of U.S. military heavy transports, including the Lockheed C-5M Super Galaxy. More than 8,000 CF6s were built across the -6, -50, and -80 series, and the engine remains in service on hundreds of in-production freighters and presidential aircraft. The CF6 is the direct civil derivative of the TF39 — the world's first high-bypass turbofan, developed for the C-5 Galaxy — and the foundation on which GE built the GE90 and GEnx successors.

GE began CF6 development in 1968 to give airlines a civil high-bypass engine for the new generation of widebodies, leveraging TF39 design knowledge but with civil-grade durability and lower specific fuel consumption. The CF6-6 launched on the McDonnell Douglas DC-10-10 in 1971 at 40,000 lbf with a 93-inch fan. The CF6-50 followed in 1973 at 51,000-54,000 lbf for the DC-10-30 and Airbus A300 launch — the engine that opened the European widebody market for an American supplier.

The defining variant proved to be the CF6-80C2, certified in 1985. With a higher-pressure-ratio core, double-annular combustor option, and FADEC introduction, the -80C2 ran at 52,500-62,100 lbf with a 93-inch fan and a 5.1:1 bypass ratio. It powered the Boeing 747-400 (CF6-80C2B1F), McDonnell Douglas MD-11, Boeing 767-200/-300/-400ER, Airbus A300-600, A310-300, and the McDonnell Douglas KC-10 Extender. The CF6-80E1 (67,500-72,000 lbf) extended the family to the early Airbus A330 alongside the Rolls-Royce Trent 700 and Pratt & Whitney PW4000.

Military service runs deep. The F103 designation covered CF6-50 engines on the KC-10A Extender (1981) and E-4B Nightwatch airborne command post. The F138 designation applied to CF6-80C2L1F engines that re-engined the entire C-5 Galaxy fleet from C-5A/B to C-5M Super Galaxy between 2006 and 2018, raising thrust by 22%, climb rate by 58%, and unrefuelled range by 11%. Two Boeing VC-25A Air Force One aircraft (heavily modified 747-200Bs) also run CF6-80C2B1 engines.

Production wound down in the mid-2010s as the GEnx replaced the CF6 on new 747-8 and 787 builds. New-engine deliveries ceased around 2018, but CF6 spares manufacturing continues at GE's Evendale, Ohio facility to support the in-service fleet on 767-300F freighters (still in production for FedEx and UPS), the C-5M, the E-4B, the KC-10 (retiring 2024), and VC-25A. The CF6 logged more than 400 million flight hours over its production life — a benchmark that the GE90 and GEnx have yet to match.

For Kids — a shorter, friendlier version

The General Electric CF6 is a jet engine. It was made starting in 1971. Jet engines push aircraft through the sky by blasting hot air out the back. The CF6 is called a high-bypass turbofan, which means it uses a giant front fan to move lots of air around the engine core.

The CF6 powered many famous wide passenger jets. These include the DC-10, the MD-11, the Boeing 747-400, the Boeing 767, and the Airbus A300 and A330. It also powers big military cargo planes, like the giant C-5M Super Galaxy.

The CF6 fan at the front is wider than a large dining room table. That huge fan helps the engine run more efficiently and use less fuel. The engine can push with a force of up to 72,000 pounds. That is heavier than ten large elephants pushing at once!

GE started building the CF6 based on an earlier military engine called the TF39. The TF39 was the world's first high-bypass turbofan ever built. The CF6 took that design and made it better for airlines flying passengers every day.

More than 8,000 CF6 engines have been built over the years. That is a huge number! The CF6 also helped GE learn how to build even more powerful engines that came later, like the GE90 and GEnx.

Fun Facts

  • The CF6 first flew on the DC-10 airliner back in 1971.
  • More than 8,000 CF6 engines have been built — that is a lot of engines!
  • The CF6 can produce a pushing force heavier than ten large elephants.
  • The CF6 powers the C-5M Super Galaxy, one of the biggest cargo planes in the world.
  • The CF6 was based on the TF39, the very first high-bypass turbofan engine ever made.
  • The CF6 helped open up European airlines to American-made engines for the first time.
  • The CF6 engine family grew into three main versions: the -6, the -50, and the -80 series.
  • GE used what it learned from the CF6 to build even more powerful engines like the GE90.

Kids’ Questions

What kind of engine is the CF6?

The CF6 is a high-bypass turbofan engine. It has a very large fan at the front that pulls in huge amounts of air. Most of that air flows around the engine core, which helps save fuel. This type of engine is great for big passenger and cargo planes.

What planes use the CF6 engine?

Many famous planes use the CF6. These include the DC-10, the Boeing 747-400, the Boeing 767, and the Airbus A300 and A330. The giant military cargo plane called the C-5M Super Galaxy uses it too.

Why is the CF6 engine important?

The CF6 helped start a new era of wide passenger jets in the 1970s. It was one of the first civil high-bypass engines ever built. It also helped GE learn how to make even better engines later on, like the GE90.

How many CF6 engines have been built?

More than 8,000 CF6 engines have been built since 1971. That is a huge number of engines! Many of them are still flying today on cargo planes and special aircraft.

Variants

CF6-6 (1971)
Original variant for the McDonnell Douglas DC-10-10. 40,000 lbf, 93-inch fan, 5.7:1 bypass ratio. Around 250 built before the CF6-50 superseded it.
CF6-50 (1973)
51,000-54,000 lbf class for the DC-10-30, Airbus A300-B2/B4 launch, Boeing 747-200, and the F103-GE-100 military variant on the KC-10A Extender and E-4B Nightwatch.
CF6-80C2 (1985)
Workhorse variant. 52,500-62,100 lbf, 93-inch fan, FADEC-equipped. Boeing 747-400, MD-11, 767-200/-300/-400ER, A300-600, A310-300, KC-10, VC-25A Air Force One, and C-5M Super Galaxy (as F138-GE-100B).
CF6-80E1 (1995)
Largest CF6, 67,500-72,000 lbf for the Airbus A330-200/-300 alongside the Rolls-Royce Trent 700 and PW4000-100. 96.8-inch fan, 5.0:1 bypass.
F138-GE-100B (military)
CF6-80C2L1F derivative re-engining the entire C-5 Galaxy fleet between 2006 and 2018 as the C-5M Super Galaxy programme. Raised takeoff thrust 22% and cut takeoff distance 30%.

Notable Operators

Boeing 747-400 and Boeing 767
CF6-80C2B1F on the 747-400 split the market with Rolls-Royce RB211-524 and Pratt & Whitney PW4000 — GE held around 40% share across the 694-airframe production run. On the 767 the CF6-80A and -80C2 held similar share against the PW4000.
McDonnell Douglas DC-10 and MD-11
CF6-6 launched the DC-10-10 in 1971 and CF6-50 powered the DC-10-30. The CF6-80C2 became the defining engine of the MD-11 trijet — 200 built between 1990 and 2000 for FedEx, UPS, KLM, Lufthansa Cargo, and others.
Airbus A300 / A310 / early A330
CF6-50C2 broke into Europe on the A300-B4 in 1974 and CF6-80E1 powered around one-third of early A330 deliveries. Operators include Lufthansa, Air France, Singapore Airlines, KLM, Iberia, and many cargo carriers.
U.S. Air Force special-mission fleet
C-5M Super Galaxy (F138), KC-10 Extender (F103, retired 2024), E-4B Nightwatch (F103), and VC-25A Air Force One (CF6-80C2B1) — the engine that powers the U.S. national command and presidential air fleet.

Frequently Asked Questions

What is the relationship between the CF6 and the TF39?

The TF39, developed in the 1960s for the original Lockheed C-5A Galaxy, was the world's first high-bypass turbofan and produced 41,000 lbf at an 8:1 bypass ratio. GE adapted the TF39 core for civil use and the result, the CF6-6, launched on the DC-10-10 in 1971. The CF6 family inherited the TF39's two-shaft layout, large single-stage fan, and high-bypass aerodynamics, but with civil-grade durability and emissions compliance.

How does the CF6-80C2 differ from the original CF6-6?

The -80C2 ran a higher-pressure-ratio core (30:1 versus 25:1 on the -6), introduced FADEC engine control, raised thrust 50%, and cut specific fuel consumption around 10%. It also added the option of a double-annular combustor for lower NOx. The 93-inch fan diameter stayed the same, allowing -80C2 retrofits to existing -50 nacelles on some airframes. The result was a single-engine family covering 50,000 to 62,000 lbf across four major airframes.

Is the CF6 still in production?

New-engine deliveries ended around 2018. GE Aerospace continues to manufacture spares, modules, and complete replacement engines for the in-service fleet at Evendale, Ohio. The Boeing 767-300F freighter remains in production for FedEx and UPS through 2027 under the EPA pre-merit exemption, sustaining a small new-build CF6-80C2 production trickle. The GE CF6 programme page tracks the fleet status.

What replaced the CF6?

The GE GEnx (introduced 2011 on the Boeing 787 and 747-8) replaced the CF6-80C2 on the 747 line and serves the 787. Bypass ratio rises to 9:1, fan diameter to 111 inches (787) or 104 inches (747-8), and fuel burn drops around 15% versus the CF6-80C2.

How many flight hours has the CF6 logged?

More than 400 million flight hours across the global fleet by 2024, according to GE Aerospace. The CF6-80C2 sub-family alone has logged more than 300 million hours and remains the highest-time variant. With 8,000+ engines delivered and many still flying past 2040 on the C-5M and 767-300F, the cumulative total will continue to climb.

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