Inside The World’s Most Highly effective Fighter Engine

The F-35 Lightning II is the world’s most succesful fighter jet and is ready to carry out a variety of missions. What’s uncommon for a fighter jet of its dimension is that it solely has a single engine. The F-16 Combating Falcon solely has a single engine, however it is usually a a lot smaller airplane. Giant multirole fighter jets around the globe, from the F-22 Raptor to the Eurofighter Hurricane, have two engines. In the meantime, the so-called J-36 next-generation fighter noticed flying in China throughout late 2024 has three engines.

The F-35 is powered by a single Pratt & Whitney F135 afterburning turbofan. The F-35 is by far essentially the most produced fighter jet in the USA. In 2024, it accounted for 110 of the 153 fighter jets US trade delivered, and in 2025, Lockheed Martin is planning to ship a report 170 to 190 F-35s, together with these for export. Here’s what to know concerning the highly effective engine powering the Lightning II.

The Sudden Situation With Single-Engined Plane

As a single-engine fighter jet, the F-35 Lightning II drew the ire of President Trump in Could 2025 when he confusingly acknowledged “We’re going to do an F-55, and I believe — if we get the best value, we now have to get the best value — that’ll be two engines and a brilliant improve on the F-35.” He additionally stated, “I don’t like single engines… if an engine goes out, it’s good to have two, three, or 4. That’s why, I just like the 747, it’s bought 4…”

The statements caught many individuals without warning. Reconfiguring the F-35 with two engines can be something however the easy improve that the President acknowledged. It could quantity to an nearly full redesign of the plane. Former Air Power Secretary Frank Kendall advised Breaking Protection that not solely wouldn’t it be a brand new design, however “It’s an choice that was by no means offered and that we by no means thought of, to my information.”

At the very least for now, the F-35 will proceed to be made with its single Pratt & Whitney F135 afterburning turbofan. It appears unlikely that the F-35 shall be redesigned to hold two engines. Whereas there are cases of the F-35 crashing, it does not crash greater than its friends. Nonetheless, its mishaps are extra closely reported as a result of it’s such a high-profile airplane.

The Pratt & Whitney F135 Afterburning Turbofan

Pratt & Whitney’s F135 solely powers the F-35 household of plane, together with the F-35A, F-35B, and F-35C. The LiftSystem for STOVL operations within the F-35B is supplied by Rolls-Royce. The engine efficiently outcompeted the Basic Electrical/Rolls-Royce F136 turbofan to be chosen because the engine to energy the F-35.

The primary manufacturing engines had been delivered in 2009 and had been based mostly on the Pratt & Whitney F119 engine that had been developed for the F-22 Raptor. The dual-engined Raptor is powered by two F119 engines. The F-35’s F136 engine has been designed to supply 43,000 lbf with its afterburner and round 28,000 lbf with out the afterburner.

The F135 can also be designed to enhance the low-observable signature (stealth) of the F-35. It has been designed with glorious thermal administration to cut back its detectability. Against this, the Russian Sukhoi Su-57 is powered by two Saturn AL-41F1 afterburning turbofans, that are variants of the engines used to energy the non-stealthy Su-34/Su-30 Flanker sequence of plane. The meant Saturn AL-51 turbofan with a lowered signature nonetheless hasn’t been fitted onto these jets.

Continuous Enhancements

Like different engines, the F135 is continually improved and upgraded. Enhancements embrace decreasing the F135’s gasoline burn and growing its reliability whereas decreasing the wanted upkeep. Lowering gasoline burn is essential within the Air Power, as elevated effectivity permits the plane to have an elevated vary. Vary is among the best limitations of recent fighter jets, exacerbated by the elevated vulnerability of tanker plane.

Enhancements will see the F135 engine have elevated thrust and higher thermal administration. Extra enhancements are deliberate as a part of the Engine Core Improve (ECU) for the F-35’s future Block IV improve (anticipated round 2029). Pratt & Whitney says that because the F-35 fighter jet is modernized to incorporate new capabilities wanted to defeat future threats, the Engine Core Improve will present the elevated efficiency to satisfy these necessities.

It needs to be famous that top velocity was by no means the core a part of the engine’s design. In truth, the F-35 was slowed down from a deliberate cruise Mach of 1.8 to 1.6, making it significantly slower than the F-22 and even the F-4 Phantom II. It is because classes realized from prior conflicts are that fighter jets maneuver at slower speeds in battle eventualities, excessive speeds burn gasoline and scale back vary, and improve warmth friction, which makes the F-35 much less stealthy.

A Generational Leap

Pratt & Whitney claims the F135 engine is the most secure and most superior engine of its sort at present in service. It says the engine “delivers a generational leap in efficiency and reliability” and that it constantly exceeds full mission functionality fee necessities of 94%. To date, greater than 1,300 F135 manufacturing engines have been delivered by Pratt & Whitney, and greater than 1,200 accomplished F-35s have been delivered by Lockheed Martin.

Rebutting issues about single-engine security and extremely publicized F-35 mishaps, Pratt & Whitney asserts its security fee is “greater than an order of magnitude higher than earlier generations of fighter engines” when put next throughout engine life cycles. The F135 has fewer elements in contrast with related engines, and this helps in enhancing the engine’s reliability.

The engine is designed to be simple to take care of with all line-replaceable elements (LRCs) in a position to be eliminated and changed with a set of six widespread hand instruments. The engine’s standing can also be digitalized because of its well being administration system, which offers maintainers with real-time information. It additionally permits them to troubleshoot points and put together wanted alternative elements earlier than the plane returns to base.

The F-35B’s Distinctive Variant

The Air Power’s standard F-35A and the primarily Navy F-35C variants use the same F135-PW-100/400 variants. The principle distinction between the -100 and the -400 is that the -400 has salt-corrosion-resistant supplies. Nonetheless, the STOVL F-35B fighter makes use of the significantly tailored F135-PW-600 variant. That variant has a barely decrease max thrust with afterburner (41,000 lbf) and is heavier with a dry weight of seven,260 lbs in contrast with the -100/400 dry weight of 6,422 lbs.

The F-35B’s engine has an exhaust nozzle that rotates downwards, and it integrates with the Rolls-Royce LiftSystem to allow the fighter jet to hover on a cushion of air and land vertically. About 46% of the downward thrust is supplied by the carry fan positioned in entrance of the engine, and one other 46% is supplied by the vectoring exhaust nozzle. The remaining 8% is supplied by a nozzle in every wing.

The F-35B’s superior STOVL system was a giant cause why the Lockheed Martin X-35 gained the contract towards the competing Boeing X-32 design. One check pilot known as Phil “Rowdy” Yates, who flew the demonstrator plane, stated the X-35’s vertical carry system required 17 miracles to return collectively, they usually labored splendidly throughout testing. In the meantime, the Boeing X-32 design was principally an replace on the older Harrier soar jet design and needed to carry out its demonstrations at sea degree, the place the air was thicker.

A Worthy Fifth-Technology Engine

The F135 might not propel the F-35 to excessive speeds in contrast with different high-performance fighter jets, however it isn’t meant to. The quickest fighter jet in service at present is the Russian MiG-31 Interceptor, which might attain round Mach 2.8 in contrast with the F-35’s Mach 1.6. Nonetheless, that outdated Soviet-era fighter jet is taken into account to be approaching obsolescence, as velocity shouldn’t be the defining issue that makes fashionable fighter jets deadly.

The F-35 is designed underneath the concept “you may’t run, however you may cover,” and to that finish, the F135 turbofan has been designed to supply the Lightning II the bottom doable thermal signature. When the engine was developed, it sat on the slicing fringe of engineering. Now, Pratt & Whitney (and GE Aerospace) are working to develop the subsequent technology of engines to energy sixth-generation fighter jets.

Whereas the F135 might have been designed with sufficient energy and reliability that engineers felt they solely wanted one engine, this may occasionally not carry ahead to future fighter jets. It’s extensively believed that sixth-generation fighter jets, just like the F-47, are being developed with two engines. The Anglo-Japanese Tempest/GCAP is being designed with two engines, and the so-called J-36 fighter has three. Sixth-generation fighters shall be required to have distinctive vary and electrical energy technology to energy sensors and even lasers. These ‘system of programs’ plane are additionally set to be a lot bigger than fifth-generation fighters.