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General Electric F404

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

General Electric F404 — Aircraft Engine
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The General Electric F404 is an afterburning low-bypass turbofan in the 17,700 lbf class that defined a generation of light-fighter engines. It was designed in the 1970s as a half-scale derivative of the GE F101 bomber engine, originally to power the YF-17 Cobra prototype that became the Northrop/McDonnell Douglas F/A-18 Hornet. The engine entered service in 1980 on the U.S. Navy F/A-18 Hornet and has since powered the Saab JAS 39 Gripen, the KAI T-50 Golden Eagle, the Boeing T-7A Red Hawk trainer, and the experimental Boeing X-32 and Lockheed X-35 JSF demonstrators. More than 5,000 F404 engines have been built.

The F404 uses a 3-stage fan, a 7-stage high-pressure compressor, an annular combustor, a 1-stage high-pressure turbine, a 1-stage low-pressure turbine, and a fully variable convergent-divergent afterburning nozzle. The original F404-GE-400 produced 16,000 lbf with afterburner; the current F404-GE-402 Enhanced Performance Engine produces 17,700 lbf. The engine's compact size — 154 inches long and 35 inches in maximum diameter — let designers package twin-engine fighters into airframes that would have required a single larger engine a generation earlier.

Volvo Aero (now GKN Aerospace Engine Systems) licence-builds a Swedish variant called the RM12 for the JAS 39 Gripen A/B/C/D. The RM12 is functionally an F404 with single-engine bird-strike resistance certified to Swedish requirements (the Gripen flies with one engine where the F/A-18 has two), an upgraded full-authority digital electronic control, and slightly higher thrust at 18,100 lbf. The Indian HAL Tejas Mk1 also flies the F404-GE-IN20, a variant sized to the Indian Light Combat Aircraft program.

The F404 became the parent of an entire family. The larger F414 was created in the late 1980s for the Super Hornet by scaling the F404 fan and core flow path up by roughly 14%, delivering 22,000 lbf in the same envelope. A smaller non-augmented derivative, the F125, powers the AIDC F-CK-1 Ching-Kuo fighter in Taiwan. The experimental civil GE36 unducted-fan propfan demonstrator of the late 1980s also used an F404-derived core.

Production continues at GE Aerospace's Lynn, Massachusetts plant, primarily for new Boeing T-7A Red Hawk trainers being delivered to the U.S. Air Force, KAI T-50 / FA-50 light combat aircraft for export customers, HAL Tejas Mk1A for the Indian Air Force, and ongoing JAS 39 Gripen C/D MRO. The engine has become one of GE Aerospace's longest-running military programs alongside the J79 and TF34.

For Kids — a shorter, friendlier version

The General Electric F404 is a jet engine that powers some famous fighter jets. It was designed in the 1970s to give aircraft lots of thrust without being too big or heavy. More than 5,000 of these engines have been built!

The F404 first flew on the American Navy's F/A-18 Hornet in 1980. Since then, it has powered many other jets. These include the Saab JAS 39 Gripen, the KAI T-50 Golden Eagle, and the Boeing T-7A Red Hawk trainer.

This engine has a special nozzle at the back called an afterburner. The afterburner squirts extra fuel into the hot exhaust. This gives the jet a big boost of extra push when the pilot needs to go faster.

The F404 is smaller than you might think. It is about 154 inches long, which is longer than a tall adult lying down. But it still puts out a huge amount of thrust for its size. That is why designers love using it in fighter jets.

There are different versions of the F404. The newest version makes more thrust than the original. Engineers kept improving it over the years to make it even more powerful and reliable.

Fun Facts

  • The F404 engine was first designed in the 1970s as a smaller version of a big bomber engine.
  • More than 5,000 F404 engines have been built — that is a lot of jet power!
  • The engine is longer than a tall adult lying flat on the ground.
  • It powers the F/A-18 Hornet, which is a jet used by the American Navy.
  • The F404 uses an afterburner that burns extra fuel to give a sudden burst of speed.
  • The newest F404 version makes more thrust than the original model from 1980.
  • This engine is smaller than older engines but still packs a powerful punch.
  • The F404 also helped power two experimental jets that competed to become the famous Joint Strike Fighter.

Kids’ Questions

What makes the F404 engine special?

The F404 is special because it is small but very powerful. It has an afterburner that gives jets an extra burst of speed. Designers can fit two of these engines into a jet that used to need one giant engine.

Which jets use the F404 engine?

The F404 powers several famous jets. These include the F/A-18 Hornet, the Saab JAS 39 Gripen, the T-50 Golden Eagle, and the T-7A Red Hawk trainer. It even helped power two experimental jets in the past.

How does an afterburner work?

An afterburner sprays extra fuel into the hot gases leaving the engine. This makes a big burst of extra thrust. Pilots use it when they need a quick boost of speed.

Variants

F404-GE-400
Original 1980 production variant for the U.S. Navy F/A-18A/B Hornet. 16,000 lbf afterburning, 10,700 lbf dry. The variant flown on early Australian, Canadian, and Spanish Hornets.
F404-GE-402 Enhanced Performance Engine (EPE)
1992 upgrade with 10% more thrust (17,700 lbf afterburning) and full-authority digital electronic control. Standard engine on F/A-18C/D Hornets and most international F/A-18 fleets.
Volvo Aero RM12
Swedish licence-built variant for the JAS 39 Gripen A/B/C/D. Single-engine bird-strike-certified, FADEC-controlled, 18,100 lbf afterburning. Built by Volvo Aero (now GKN Aerospace) under licence from GE.
F404-GE-IN20
Indian variant for the HAL Tejas Mk1A light combat aircraft. 19,000 lbf afterburning class. The interim engine until the HAL Tejas Mk2 transitions to the GE F414.
F404-GE-102
Trainer-tuned variant for the KAI T-50 Golden Eagle and Boeing T-7A Red Hawk. 17,700 lbf afterburning with reduced wear-rate hot section tuned for high-cycle training fleet use.
F404/RM12 demonstrators
F404 variants powered the YF-17, the Boeing X-32 JSF demonstrator, and the Lockheed X-35 JSF demonstrator (which later led to the F-35 / F135 program).

Notable Operators

F/A-18 Hornet (1980-present)
The original launch platform. Two F404 engines per airframe. U.S. Navy F/A-18A/B/C/D retired from front-line U.S. service in 2019 but still flown by Australia, Canada, Finland, Kuwait, Malaysia, Spain, and Switzerland.
JAS 39 Gripen (1996-present)
Saab JAS 39 Gripen A/B/C/D fly the Volvo Aero RM12 variant. One engine per airframe. Operators include Sweden, Czech Republic, Hungary, South Africa, Thailand, and Brazil. Gripen E/F transitions to the larger F414.
KAI T-50 / FA-50 (2002-present)
Korean T-50 Golden Eagle trainer and FA-50 light combat aircraft. Operators include South Korea, Indonesia, Iraq, Philippines, Thailand, Malaysia, and Poland.
T-7A Red Hawk (2024-present)
U.S. Air Force T-7A Red Hawk jet trainer replacing the T-38 Talon. Single engine per airframe. Currently in early production at Boeing St. Louis.
HAL Tejas Mk1/Mk1A (2016-present)
Indian Air Force HAL Tejas light combat aircraft flies the F404-GE-IN20. Mk1A deliveries ongoing in 2026. The Mk2 will transition to the larger GE F414.

Frequently Asked Questions

What aircraft use the GE F404?

The F404 powers the F/A-18 Hornet (two engines), the Saab JAS 39 Gripen A/B/C/D (Volvo RM12 variant), the KAI T-50 Golden Eagle and FA-50, the Boeing T-7A Red Hawk, and the HAL Tejas Mk1/Mk1A (F404-GE-IN20 variant). It also flew on the YF-17 Cobra and the X-32 and X-35 Joint Strike Fighter demonstrators (GE Aerospace F404 page).

How much thrust does the F404 produce?

The current F404-GE-402 Enhanced Performance Engine produces 17,700 lbf with afterburner and around 11,000 lbf dry. The original F404-GE-400 produced 16,000 lbf. The Swedish RM12 variant on the Gripen produces 18,100 lbf, slightly above the U.S. baseline thanks to higher turbine inlet temperatures.

What's the relationship between the F404 and the F414?

The F414 is a larger derivative of the F404, developed in the 1990s for the Boeing F/A-18E/F Super Hornet. It scales the F404 fan and core flow path up by roughly 14% in the same external envelope, raising thrust from 17,700 lbf to 22,000 lbf while preserving engine bay compatibility. Both engines share many parts at the maintenance level.

Why does the Gripen fly a Volvo-built engine instead of the GE F404?

The Saab JAS 39 Gripen is a single-engine fighter, so it cannot afford the same bird-strike risk as the twin-engine F/A-18. Volvo Aero (now GKN Aerospace) licence-built the RM12 variant with strengthened fan blades, single-engine bird-strike certification to Swedish military requirements, a Volvo-developed full-authority digital electronic control, and slightly higher thrust at 18,100 lbf. The core is otherwise identical to the F404.

Is the F404 still in production?

Yes. GE Aerospace builds the F404 at its Lynn, Massachusetts plant for the Boeing T-7A Red Hawk, KAI T-50/FA-50 exports, and the HAL Tejas Mk1A program (GE Aerospace F404 page). More than 5,000 engines have been built across the family's 45-year production run.

Which JSF demonstrators flew the F404?

Both the Boeing X-32 and the Lockheed Martin X-35 Joint Strike Fighter concept demonstrators flew with F404 derivatives. Lockheed won the JSF competition in 2001, and the production F-35 transitioned to the much larger Pratt & Whitney F135. The F404 also powered the earlier Northrop YF-17 Cobra prototype that became the F/A-18 Hornet.

Sources

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