Reading level:

General Electric F101

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

General Electric F101 — Aircraft Engine
Open in interactive gallery →

The General Electric F101 is an afterburning turbofan that powers the Rockwell B-1B Lancer long-range bomber fleet of the U.S. Air Force. Each B-1B carries four F101-GE-102 engines mounted in pairs under fixed inboard pylons, producing more than 30,000 lbf of afterburning thrust per engine. The F101 was GE's first turbofan with an afterburner and became the architectural ancestor of two later engine families: the F110 fighter turbofan used on the F-16 and F-15, and the CFM56 civil turbofan co-produced with Snecma that powers most of the worldwide Boeing 737 and Airbus A320 fleets.

Development began in 1970 for the AMSA program that became the B-1A bomber, with the requirement that the engine deliver sustained supersonic dash speed at low altitude — a regime that punishes any propulsion system with high inlet temperatures and heavy fuel burn. The F101 uses a 2-stage fan, a 9-stage high-pressure compressor, an annular combustor, a 1-stage high-pressure turbine, a 2-stage low-pressure turbine, and a variable-area convergent-divergent afterburning nozzle.

The B-1A program was cancelled by President Jimmy Carter in 1977, suspending F101 production after a small prototype batch. Production resumed in 1982 under President Ronald Reagan when the program was revived as the B-1B, with the engine downrated slightly for longer service life and re-designated F101-GE-102. Total production was 469 engines, supporting a fleet of 100 B-1B airframes built between 1985 and 1988.

The cancellation of the B-1A handed GE an unexpected opportunity. The F101 core was reworked into a much smaller bypass-ratio engine for fighter use, becoming the F110 that won a major slice of F-16 production in the 1984 "Great Engine War" against the Pratt & Whitney F100. The same core was also paired with a much larger fan and reduced afterburner to create the CFM56 commercial turbofan, which has now been built in numbers exceeding 30,000 — the highest-volume jet engine in aviation history.

The F101 itself is no longer in production, but General Electric Aerospace continues to support the in-service fleet under a long-term sustainment contract with the U.S. Air Force. The B-1B fleet is scheduled for retirement in the 2030s as the Northrop Grumman B-21 Raider enters service, at which point the F101 will exit the active inventory after roughly 50 years of front-line use.

For Kids — a shorter, friendlier version

The General Electric F101 is a powerful jet engine. It was made for a big bomber plane called the B-1B Lancer. The American Air Force uses the B-1B to fly long distances at high speed. Each B-1B has four F101 engines to push it through the sky.

The F101 is special because it has an afterburner. An afterburner shoots extra fuel into hot exhaust gas. This gives the engine a huge burst of extra push. It helped the B-1B fly fast at very low heights above the ground.

Engineers started building the F101 in 1970. It was General Electric's first turbofan engine with an afterburner. The design work took many years. President Jimmy Carter stopped the first bomber program in 1977, but the engine design lived on.

The F101 became the parent of two famous engine families. One became the F110, used on jet fighters like the F-16. The other became the CFM56, used on passenger planes like the Boeing 737. The CFM56 now flies millions of people around the world every day. That means one engine design helped build both warplanes and airliners!

Four F101 engines together make more push than most people can imagine. Each engine alone makes over 30,000 pounds of force with the afterburner on. That is heavier than a large dump truck being pushed through the air every single second.

Fun Facts

  • The B-1B Lancer carries four F101 engines, two tucked under each side of the plane.
  • The F101 was General Electric's very first turbofan engine to include an afterburner.
  • One F101 engine produces more than 30,000 pounds of pushing force — heavier than a large dump truck.
  • The F101's design was the parent that led to the F110 engine used on F-16 fighter jets.
  • The CFM56 engine, a cousin of the F101, now powers most Boeing 737 and Airbus A320 planes worldwide.
  • Engineers began designing the F101 all the way back in 1970.
  • Flying fast at very low altitude is one of the hardest things a jet engine can do, and the F101 was built for exactly that.
  • The first bomber the F101 was built for, called the B-1A, was cancelled before it ever entered service.

Kids’ Questions

What plane does the F101 engine power?

The F101 engine powers the B-1B Lancer, a big long-range bomber used by the American Air Force. Each B-1B has four of these engines to help it fly fast and far.

What is an afterburner and why does it matter?

An afterburner adds extra fuel to the hot gases leaving an engine. This creates a big extra burst of pushing force. It helps planes fly faster when they really need speed.

How did the F101 help create other engines?

The F101's design was used to build two new engine families. One became the F110, used on fighter jets. The other became the CFM56, used on passenger airliners that carry people every day.

Why was the F101 program stopped for a while?

President Jimmy Carter cancelled the B-1A bomber program in 1977. That meant the F101 engine did not need to be made in large numbers right away. But the engine design was saved and used later for the B-1B and other planes.

Variants

F101-GE-100
Original 1976 production engine for the cancelled B-1A. 30,000 lbf class afterburning thrust. Only a small prototype batch was built before Jimmy Carter terminated the B-1A in 1977.
F101-GE-102
Revived 1982 variant for the B-1B Lancer. 30,780 lbf afterburning, 17,390 lbf dry. Slightly derated from the -100 for longer service life given the B-1B's heavier focus on low-altitude penetration than supersonic dash. 469 built between 1982 and 1988.
F101 DFE (Derivative Fighter Engine)
Re-fanned smaller-bypass derivative that flew on the F-16/101 and F-14/F101DFE demonstrator aircraft in 1980-1981. Did not enter production under the F101 name but evolved into the F110 fighter engine and the CFM56 civil engine.

Notable Operators

B-1B Lancer (1985-present)
The B-1B Lancer is the only in-service F101 platform. Four engines per airframe, U.S. Air Force Global Strike Command service, roughly 45 aircraft remaining in 2026 from the original 100 delivered.

Frequently Asked Questions

What aircraft use the GE F101?

Only the Rockwell B-1B Lancer long-range bomber, which carries four F101-GE-102 engines per airframe (USAF B-1B fact sheet). The engine was originally designed for the cancelled B-1A and re-entered production with the revived B-1B program in 1982. No other aircraft uses the F101.

How much thrust does the F101 produce?

The F101-GE-102 produces 30,780 lbf with afterburner and 17,390 lbf dry. Each B-1B has four engines for a total of 123,120 lbf of afterburning thrust, enough to lift a 477,000 lb airframe at maximum take-off weight off the runway.

How does the F101 relate to the F110 and CFM56?

Same core, different fans and bypass ratios. The F101 has a 2-stage fan and moderate bypass. GE re-fanned the core with a smaller, faster spool to create the F110 fighter turbofan in the 1980s, and re-fanned it again with a much larger fan and no afterburner to create the CFM International CFM56 commercial turbofan (built jointly with Snecma). The CFM56 has been built in numbers exceeding 30,000 — the highest-volume jet engine in aviation history.

Is the F101 still in production?

No. Production ran from 1976 (small prototype batch for the B-1A) through 1988 (B-1B production end) and stopped at 469 engines. GE Aerospace continues to support the in-service fleet through depot overhaul and parts manufacture, but new engines are no longer built. The B-1B is scheduled to retire in the 2030s as the B-21 Raider enters service.

Why was the B-1A cancelled and then revived?

President Jimmy Carter cancelled the B-1A in 1977, citing its high cost and arguing that air-launched cruise missiles carried by older B-52s could perform the same penetrating strike mission at lower cost. President Ronald Reagan revived the program in 1981 as the B-1B, with a heavier emphasis on low-altitude radar evasion than on supersonic dash. The F101 returned to production with the slightly derated -102 dash-number suited to the B-1B's revised mission profile.

Sources

See Also