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’s also a a lot smaller airplane. Massive multirole fighter jets world wide, from the F-22 Raptor to the Eurofighter Storm, 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 probably the most produced fighter jet in the USA. In 2024, it accounted for 110 of the 153 fighter jets US business 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 Surprising Situation With Single-Engined Plane

As a single-engine fighter jet, the F-35 Lightning II drew the ire of President Trump in Might 2025 when he confusingly said “We’re going to do an F-55, and I believe — if we get the fitting worth, we’ve to get the fitting worth — that’ll be two engines and an excellent improve on the F-35.” He additionally mentioned, “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 acquired 4…”

The statements caught many individuals abruptly. Reconfiguring the F-35 with two engines could be something however the easy improve that the President said. It will quantity to an virtually full redesign of the plane. Former Air Power Secretary Frank Kendall informed Breaking Protection that not solely would it not be a brand new design, however “It’s an choice that was by no means introduced and that we by no means thought-about, to my information.”

No less than 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 will likely be redesigned to hold two engines. Whereas there are cases of the F-35 crashing, it does not crash greater than its friends. Nevertheless, 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 Common 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 offer 43,000 lbf with its afterburner and round 28,000 lbf with out the afterburner.

The F135 can be designed to enhance the low-observable signature (stealth) of the F-35. It has been designed with wonderful thermal administration to cut back its detectability. In contrast, 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 collection of plane. The supposed Saturn AL-51 turbofan with a diminished signature nonetheless hasn’t been fitted onto these jets.

Continuous Enhancements

Like different engines, the F135 is continually improved and upgraded. Enhancements embody lowering the F135’s gas burn and rising its reliability whereas lowering the wanted upkeep. Lowering gas burn is essential within the Air Power, as elevated effectivity permits the plane to have an elevated vary. Vary is without doubt one of 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 fulfill these necessities.

It ought to be famous that prime velocity was by no means the core a part of the engine’s design. In reality, 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’s because classes discovered from prior conflicts are that fighter jets maneuver at slower speeds in battle eventualities, excessive speeds burn gas and cut back vary, and enhance 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 presently in service. It says the engine “delivers a generational leap in efficiency and reliability” and that it repeatedly exceeds full mission functionality charge 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 charge is “greater than an order of magnitude higher than earlier generations of fighter engines” compared throughout engine life cycles. The F135 has fewer components in contrast with related engines, and this helps in bettering the engine’s reliability.

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

The F-35B’s Distinctive Variant

The Air Power’s typical F-35A and the primarily Navy F-35C variants use the same F135-PW-100/400 variants. The primary distinction between the -100 and the -400 is that the -400 has salt-corrosion-resistant supplies. Nevertheless, 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 elevate 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 an enormous 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, mentioned the X-35’s vertical elevate system required 17 miracles to return collectively, and so they labored splendidly throughout testing. In the meantime, the Boeing X-32 design was largely an replace on the older Harrier leap jet design and needed to carry out its demonstrations at sea stage, 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’s not supposed to. The quickest fighter jet in service right now is the Russian MiG-31 Interceptor, which might attain round Mach 2.8 in contrast with the F-35’s Mach 1.6. Nevertheless, that outdated Soviet-era fighter jet is taken into account to be approaching obsolescence, as velocity isn’t the defining issue that makes fashionable fighter jets deadly.

The F-35 is designed below the thought “you possibly can’t run, however you possibly can 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 reducing fringe of engineering. Now, Pratt & Whitney (and GE Aerospace) are working to develop the following 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 will likely 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 will likely be required to have distinctive vary and electrical energy technology to energy sensors and even lasers. These ‘system of techniques’ plane are additionally set to be a lot bigger than fifth-generation fighters.