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General Electric TF34

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

General Electric TF34 — Aircraft Engine
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The General Electric TF34 is a high-bypass turbofan developed in the late 1960s for the U.S. Navy's S-3 Viking carrier-based anti-submarine aircraft and adopted by the U.S. Air Force for the A-10 Thunderbolt II close-air-support aircraft. First run in 1971 and entering service in 1972, the TF34 produces 9,275 lbf of dry thrust from a 4.0 bypass-ratio core that runs efficiently at low altitude and low subsonic speed. A civilian derivative, the CF34, was developed in the early 1980s and has gone on to power more than 4,000 Bombardier and Embraer short-haul jets — making the combined TF34/CF34 family one of the most-produced General Electric turbofan lineages.

The TF34 was the U.S. Navy's response to the requirement for a fuel-efficient long-endurance engine on the Lockheed S-3 Viking carrier-based anti-submarine aircraft. The S-3 needed nine-hour mission endurance with minimal fuel consumption to track Soviet submarines from a CVA-class flight deck. General Electric responded with a high-bypass turbofan, the first on a U.S. Navy carrier aircraft, with a 4.0 bypass ratio that cut fuel burn by around 25 percent below the contemporary low-bypass TF30. The TF34-GE-2 entered S-3 Viking service in 1972 at 9,275 lbf dry thrust.

The A-10 Thunderbolt II close-air-support aircraft adopted the TF34-GE-100 in 1975 for the U.S. Air Force's dedicated tank-killing platform. Two TF34s mounted high on the rear fuselage power the A-10 with around 18,500 lbf of total thrust. The high-mounted installation protects the engines from ground fire during low-altitude close-air-support runs, and the high-bypass core produces a relatively cool exhaust signature that complicates infrared missile lock-on. The TF34-GE-100A variant from 1985 added improved hot-section materials and longer time-on-wing. The A-10's planned retirement in 2032 will end TF34 military service.

The civilian CF34 derivative launched in 1983 as a 9,140 lbf engine for the Challenger 600 business jet. Bombardier scaled the CF34 up through the CF34-3A1 (9,220 lbf) for the Challenger 601, the CF34-3B (8,729 lbf) for the Challenger 604, and the CF34-8C (14,500 lbf) for the CRJ-700/900. The CF34-10E (20,000 lbf) powers the Embraer E190/E195. The CF34 has been the dominant 70-110-seat short-haul jet engine since the early 1990s, with around 4,000 units produced for the Bombardier and Embraer families. Production continues in 2026.

The TF34 itself is being retired alongside its airframes. The S-3 Viking was retired from U.S. Navy service in 2009; the last TF34-powered military aircraft will be the A-10 fleet, scheduled for retirement to AMARG storage in 2032 as the U.S. Air Force consolidates close-air-support around the F-35A and uncrewed systems. The CF34 family will continue in short-haul service until the late 2030s as Embraer E2 and Mitsubishi SpaceJet replacements complete their fleet rollovers. The TF34/CF34 family's combined production run from 1972 through the late 2030s will exceed 65 years.

For Kids — a shorter, friendlier version

The General Electric TF34 is a jet engine made in the late 1960s. It powers two famous military planes. These are the A-10 Thunderbolt II and the S-3 Viking. The engine first ran in 1971 and entered service in 1972.

The TF34 is called a high-bypass turbofan. This means it pulls in a lot of air around the hot core. That makes it very fuel-efficient. It can fly for a long time without burning too much fuel. The S-3 Viking could fly for nine hours on one mission!

The A-10 Thunderbolt II flies low and slow to support soldiers on the ground. The TF34 is perfect for this job. It runs well at low speeds and low heights. Each A-10 uses two of these engines.

In the early 1980s, engineers made a civilian version called the CF34. This engine now powers small passenger jets made by Bombardier and Embraer. More than 4,000 of these jets use the CF34. That makes the TF34 family one of the most-built jet engine lines ever made by General Electric.

The CF34 is smaller than the huge engines on a jumbo jet, but it is very important. It carries millions of passengers on short trips every year. The military and civilian versions together show how one great design can do many different jobs.

Fun Facts

  • The TF34 first ran in 1971 — more than 50 years ago!
  • Each engine pushes with a force of 9,275 pounds — heavier than two full-grown elephants!
  • The A-10 Thunderbolt II carries two TF34 engines, one on each side of its body.
  • The S-3 Viking used TF34 engines to hunt submarines for up to nine hours at a time.
  • The TF34 was the very first high-bypass engine ever used on an American Navy carrier plane.
  • The civilian CF34 version now powers more than 4,000 short-haul passenger jets around the world.
  • The TF34 burns about 25 percent less fuel than older jet engines of its time.
  • The TF34 and CF34 together make up one of the most-produced jet engine families General Electric has ever built.

Kids’ Questions

What planes use the TF34 engine?

The TF34 powers two military planes. These are the A-10 Thunderbolt II and the S-3 Viking. The A-10 supports soldiers on the ground, and the S-3 Viking was used to track submarines from aircraft carriers.

Is there a passenger jet version of this engine?

Yes! Engineers created a civilian version called the CF34 in the early 1980s. It powers small passenger jets made by Bombardier and Embraer. More than 4,000 of these jets use the CF34 engine today.

Why is the TF34 good at saving fuel?

The TF34 is a high-bypass turbofan engine. It pulls in a lot of cool air around its hot core. This design burns about 25 percent less fuel than older engines. That means planes can stay in the air much longer.

Variants

TF34-GE-2
Initial production variant for the S-3 Viking from 1972. 9,275 lbf dry thrust.
TF34-GE-100 / -100A
A-10 Thunderbolt II variants from 1975. Two engines per A-10 produce around 18,500 lbf of total thrust. The -100A added improved hot-section materials from 1985.
CF34-1A / -3A1 / -3B (civil)
Civilian variants for the Bombardier Challenger 600/601/604 business jet family. 9,220 lbf class.
CF34-8C / -8E
Scaled-up CF34 for the Bombardier CRJ-700/900/1000 70-100-seat short-haul jets. 14,500 lbf class.
CF34-10E
Largest CF34 variant. 20,000 lbf class, powers the Embraer E190/E195 100-120-seat short-haul jets. In production through 2026.

Notable Operators

Fairchild Republic A-10 Thunderbolt II
Twin TF34-GE-100 on the U.S. Air Force's dedicated close-air-support and tank-killing aircraft. Around 280 airframes in service in 2026; planned retirement to 2032.
Lockheed S-3 Viking
Twin TF34-GE-2 on the U.S. Navy's carrier-based anti-submarine aircraft 1972-2009. 188 airframes built; retired in 2009 when the U.S. Navy consolidated ASW around the P-8 Poseidon and helicopter ASW.
Bombardier CRJ-700/900/1000
Twin CF34-8C5 on the CRJ-700/900 series and twin CF34-8E5 on the CRJ-1000. More than 1,500 airframes built; operated by Lufthansa CityLine, Air France Hop, Delta Connection, American Eagle, Skywest, Mesa, and many smaller carriers.
Embraer E190/E195
Twin CF34-10E on the larger Embraer E-Jet variants. More than 1,500 airframes built; operated by JetBlue, Air Canada Express, KLM Cityhopper, Lufthansa CityLine, and many flag and feeder carriers worldwide.

Frequently Asked Questions

Why high-bypass on a military engine?

Low-altitude fuel economy and infrared signature. High bypass ratios (the TF34 runs 4.0, versus 0.7 for the contemporary TF30) cut specific fuel consumption by around 25 percent at low subsonic cruise — critical for the S-3 Viking's nine-hour anti-submarine missions and the A-10's long loiter time over Forward Edge of Battle Area engagements. The high bypass ratio also mixes hot core air with cool bypass air, lowering exhaust temperature and reducing infrared-missile vulnerability against shoulder-fired SAMs.

Why are the A-10's engines mounted so high?

Three reasons. First, the high mounting protects the engines from ground fire during low-altitude close-air-support runs and from foreign-object-damage on rough forward airstrips. Second, the high position shields the engine inlets from the gun gas of the A-10's 30mm GAU-8 Avenger cannon, which fires at around 4,200 rounds per minute and produces meaningful exhaust gas. Third, the high mounting allows ground crews to service the engines without ladders or aircraft jacks (USAF A-10 fact sheet).

What is the CF34 and how does it relate to the TF34?

The CF34 is the civilian commercial designation for the TF34 architecture. General Electric scaled the TF34 core up through the 1980s and 1990s to produce a family of short-haul jet engines, from the 9,220-lbf CF34-3A1 on the Bombardier Challenger 601 to the 20,000-lbf CF34-10E on the Embraer E190. The CF34 shares the TF34's basic core architecture, bypass-duct design, and rear-fuselage mounting convention.

When will the A-10 retire?

2032, under the current U.S. Air Force long-range plan. The U.S. Air Force has cited the cost of supporting an aging single-mission airframe and the availability of the F-35A and uncrewed close-air-support systems as reasons for retirement. Congressional and Army opposition has slowed previous retirement attempts; the 2032 timeline reflects the most recent Fiscal Year 2025 budget submission. After A-10 retirement, no military TF34 applications will remain.

What replaced the S-3 Viking?

For carrier-based fixed-wing anti-submarine warfare, nothing — the U.S. Navy ended the carrier-based ASW mission entirely with S-3 retirement in 2009. The land-based maritime patrol mission moved to the Boeing P-8 Poseidon (a CFM56-7B-powered 737-800 derivative). The S-3's secondary aerial-refuelling tanker role went unfilled until the carrier air wings rebuilt aerial refuelling with the MQ-25 Stingray uncrewed tanker. The MQ-25 entered service in 2026 with the U.S. Navy's first carrier-based uncrewed aerial vehicle.

Is the CF34 still in production?

Yes, in 2026. The CF34-10E and CF34-8E5 continue in production for the Embraer E190/E195 first-generation E-Jet aftermarket and for new CRJ production. The next-generation Embraer E2 family uses the Pratt & Whitney PW1900G geared turbofan, ending Embraer's CF34 dependence for new types, but the installed CF34 fleet will fly through the late 2030s.

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