Trump Floats Ambitious Idea for a Twin-Engine “F-55” Fighter Jet; Sparking Debate Over New Aircraft Design

Former President Donald Trump has proposed a significant shift in U.S. fighter jet design, suggesting a new version of the F-35 stealth fighter with two engines—an aircraft he says he would call the “F-55.” While the idea has drawn attention for its boldness, military experts and former program insiders warn that such a redesign would effectively require creating an entirely new plane from the ground up.

This week at a business meeting in Qatar, Trump talked about the idea. He said, “The F-35, we’re doing an upgrade—simple upgrade—but we’re also doing an F-55. I’m going to call it an F-55,” citing his aversion to single-engine aircraft. He referred to the projected F-55 as a “super upgrade” with two engines for increased safety and performance.

A Conceptual Overhaul of the F-35

Lockheed Martin makes the Pratt & Whitney F-35 engine that the F-35 Lightning II will use.  The world’s strongest jet engine is here. But the plane’s structure, software, and internal systems are all carefully built around a single motor.

 According to retired US Air Force Lt. Col. Eric Gunzinger, who worked on the F-35 program, adding a second engine would necessitate a significant redesign. “It’s not just adding another engine—it’s reinventing the whole plane,” he said. “From hardware to software to aerodynamics, everything changes.”

He emphasized that this would not be a mere “upgrade,” as Trump suggested, but the birth of an entirely new fighter platform—a process that could span decades and cost billions.

F-55: Ambition versus Reality.

Trump’s “F-55” idea comes while both the F-35 and the older F-22 Raptor are receiving major improvements.  These include F-35 Block IV upgrades and Tech Refresh 3, which aim to improve sensor capabilities, weapon systems, and stealth materials.  These are part of defined upgrading paths that have previously been funded and are underway.

 In comparison, the F-55 would completely break from that approach.

 While the attractiveness of a twin-engine aircraft is based on safety and performance (redundancy in the event of engine failure), its feasibility is uncertain. Gunzinger, who also flew the twin-engine F-111 Aardvark, acknowledged that dual engines can indeed prevent catastrophic losses. However, he pointed out that the F-35’s architecture is built exclusively for a single engine due to compromises made to meet the needs of the Air Force, Navy, and Marine Corps.

Among the most complex variants is the F-35B, designed for short takeoff and vertical landing (STOVL) via a unique lift-fan system. Engineers agree: putting two engines into the F-35B variant is nearly impossible. “It’s technologically a bridge too far,” Gunzinger noted.

Military and Industry Response: Cautious Optimism or Dismissal?

So far, the Pentagon and Lockheed Martin have remained largely silent on Trump’s twin-engine proposal. A spokesperson for Lockheed offered a diplomatic statement, saying only that the company is “looking forward to supporting the administration’s vision for air dominance.”

Frank Kendall, former Secretary of the Air Force, was more direct. In an interview with Breaking Defense, he dismissed the twin-engine idea as a concept that had never even been entertained during his tenure. “It would be virtually a complete redesign,” he stated.

Industry insiders also view the timing as questionable. Lockheed Martin CEO James Taiclet recently announced plans to “supercharge” the F-35 into a “fifth-generation-plus” fighter, featuring stealthier materials, more advanced sensors, and longer-range weaponry—but no mention was made of a second engine.

Twin-Engine Fighters: Proven, But Not Plug-and-Play

The allure of twin-engine jets is not new. The U.S. Air Force’s F-22 Raptor, Russia’s Su-57, and China’s J-20 and J-35 fighters all boast dual engines. Notably, the Chinese J-35 has drawn comparisons to the F-35, appearing visually similar but featuring two engines.

Still, experts caution against assuming that adding another engine equates to a better aircraft. The F-35’s single engine has 43,000 pounds of thrust, which is more than any other jet engine.  The F-22’s two engines produce about 70,000 pounds of thrust between them, but the plane’s range and ability to carry different loads are less flexible than the F-35’s.

Budgetary and Strategic Implications

Redesigning the F-35 into a twin-engine F-55 would demand massive investment—something analysts say the current defense budget cannot accommodate without major tradeoffs.

“You’d have to choose,” Gunzinger warned. “Do you want the F-55, which is essentially a new plane, or do you want the NGAD [Next Generation Air Dominance] fighter?” The latter, a sixth-generation platform in development by Boeing, is expected to redefine U.S. air combat capabilities.

Pursuing both would strain defense resources and risk delays to both programs.

Conclusion: Visionary or Vanity Project?

Trump’s comments have certainly stirred debate within defense circles, with some seeing visionary ambition and others labeling the idea as impractical and premature. Unless there’s a classified project already underway—something not uncommon in military aviation history—experts agree that the so-called F-55 remains more political theater than policy reality.

Even so, the conversation has drawn fresh attention to the limitations and capabilities of America’s current fleet of fighter jets and the difficult trade-offs that come with innovating at the bleeding edge of aerospace technology.

Trump’s F-55 Fighter Vision: How It Compares to Modern Air Superiority Programs

The Next Generation Air Dominance (NGAD) Dilemma

The Pentagon is putting a lot of effort into the Next Generation Air Dominance (NGAD) program to make a sixth-generation fighter that will replace the F-22 Raptor. Trump’s idea about the F-55 is very bad for making plans. NGAD, led by Boeing and deeply funded by the U.S. Air Force, aims to deliver not just a fighter, but an integrated family of systems that includes drones, advanced AI, and cutting-edge stealth capabilities.

Gunzinger and other defense experts argue that allocating funds to both the F-55 and NGAD could jeopardize the progress of either. “It’s not just a matter of building planes. It’s about maintaining superiority in a rapidly evolving global landscape,” said one defense analyst. “Every dollar spent has to count.”

While the F-35 was conceived as a “joint strike fighter” capable of serving multiple military branches with slight modifications, the NGAD is being built with air dominance as its sole purpose. The F-55, if pursued, would likely need to straddle both roles to justify its existence—a challenging feat without massive investment and time.

Political Theater or Serious Proposal?

For critics, the F-55 proposal is just another example of Trump’s penchant for grand announcements that lack policy depth. But for supporters, it signals a willingness to push defense innovation beyond bureaucratic inertia. Either way, the proposal has ignited conversations across Capitol Hill, defense think tanks, and within the defense industry itself.

Some lawmakers have begun inquiring whether such a redesign could be explored under a new DARPA-funded program or perhaps as an offshoot of NGAD. As of now, no official legislation or appropriations have been introduced to fund or investigate the feasibility of the F-55.

What Would a Real F-55 Need?

Let’s break down what it would take to turn Trump’s “F-55” into a reality:

• Airframe Redesign: The current F-35 frame is built around a massive single engine. Twin engines would require a wider fuselage, new wings, and likely a longer airframe.
• Software Reengineering: Every system in the F-35 is integrated via a sophisticated software backbone. A new propulsion system would demand major software rewrites, which is no small feat considering the F-35’s software complexity.
• New Cooling and Fuel Systems: Two engines would create more heat and demand more fuel. That would mean more onboard cooling systems and fuel tanks, compromising stealth or internal weapon storage.
• Weight and Thrust Calculations: The addition of a second engine would increase the jet’s weight significantly. Engineers would have to reassess thrust-to-weight ratios, which impact maneuverability and performance.

Fighter Jet Programs: A Lesson in Time and Cost

Historically, fighter jet development timelines are long, and costs often spiral. For instance, the F-22 program took nearly two decades from inception to full service. The F-35 program, despite being streamlined with international partners, also took more than a decade and incurred costs of over \$1.7 trillion for development and lifetime maintenance.

Could the U.S. afford to repeat that process while simultaneously fielding NGAD, upgrading the F-22, and supporting NATO defense commitments? Experts are skeptical.

Fighter Jet Comparisons: F-35 vs. Proposed F-55 vs. F-22 vs. NGAD

Aviation Experts: The Risk of Distraction

One aviation analyst summed it up best: “Every time you suggest a new airframe, you delay capability delivery. You divert funding, and you complicate logistics, training, and maintenance. The F-35 isn’t perfect, but it’s deployable. The F-55? It’s a PowerPoint plane.”

And that’s a real concern for top brass. Operational readiness in today’s rapidly shifting global landscape—especially amid tensions with China and Russia—requires platforms that are deployable now, not in 2040.

The Role of International Partnerships

Another complication: the F-35 is part of a multinational consortium involving allies like the UK, Italy, Australia, and others. Over 1,100 jets have been delivered globally, with common training and logistics.

Introducing a new “F-55” into that mix would fracture that unity. Would allies have to buy into the new program? Would it be exclusive to the U.S.? That kind of fragmentation could weaken interoperability, the very reason the F-35 was created as a unified solution in the first place.

Trump’s Comments and the Defense Industrial Base

Trump’s backing of Lockheed Martin’s F-35 and comments about “super upgrades” come just weeks after CEO James Taiclet mentioned plans to “supercharge” the aircraft with next-gen enhancements. Though no mention was made of an additional engine, Trump’s remarks may signal alignment with Lockheed’s ambitions—or an attempt to pressure further investment.

Lockheed has not confirmed whether talks about a twin-engine variant are underway, only stating that it “looks forward to supporting the administration’s vision.”

Errors in the Twin-Engine Design of the F-35B Variant

The F-35B is the most challenging of all the F-35 models when considering a twin-engine variant.   Designed for short takeoff and vertical landing (STOVL), this version was deployed by the Marine Corps. It generates vertical force using a sophisticated mechanism comprising a swivelling back nozzle and a lift fan.

 Including a second engine to the F-35B would probably make the STOVL capability unfeasible rather than what is necessary from a new aircraft.“There’s just no room,” said Gunzinger. “The entire design is a balancing act between thrust, weight, and vertical lift systems. Throwing in a second engine would disrupt that harmony completely.”

This highlights one of the major technical barriers to creating a unified twin-engine “F-55” across all services. If the F-35B’s unique takeoff and landing abilities can’t be replicated with two engines, the new platform would either exclude Marine Corps needs or require two completely different designs under the same name, defeating the goal of joint interoperability.

The Redundancy Debate: Is One Engine Enough?

A central part of Trump’s pitch is the notion that “two engines are better than one.” That belief is common in aviation circles, particularly among military pilots who’ve had engines fail in combat scenarios. With two engines, a fighter jet can limp home. With one? The risk of losing the aircraft—and the pilot—dramatically increases.

This concern is valid. The F-16, also a single-engine fighter, has had incidents where engine failure led to total losses. Still, the engine of the F-35 is built with a great safety record and great self-monitoring capacity.  To reduce the possibility of catastrophic failure, it contains early warning systems, fail-safes, and duplicate controls.

Still, no system is perfect.  Redundancy appeals on a gut level to pilots and decision-makers both.  But in modern combat, survivability is measured not just by engine count; stealth, electronic warfare skills, situational awareness, and autonomous backup systems all play equally critical roles.

Rivals Globally and the Twin-Engine Factor

Looking at America’s strategic competitors, China and Russia have made twin-engine stealth fighters the cornerstone of their fifth-generation fleets. The Chinese J-20 and J-35 both rely on dual engines, prioritizing thrust and range. Russia’s Su-57 also features two engines and has been pitched as a heavy air superiority fighter with ground attack capabilities.

Does that mean the U.S. is behind by sticking with single-engine designs like the F-35? Not necessarily.

The F-35 was purpose-built as a lighter, more flexible multirole fighter designed to integrate with a broader range of NATO and allied forces. Its engine, the F135, is vastly more powerful than either of the Chinese or Russian designs, meaning it doesn’t need two engines to achieve comparable performance.

Still, perception matters. In the age of great power competition, maintaining both the reality and appearance of superiority has strategic value. That’s part of why Trump’s call for a “super upgrade” and a new designation (F-55) resonates with some defense observers.

The Logistics and Maintenance Puzzle

Another overlooked consequence of introducing a new twin-engine variant: the supply chain.

The F-35 program already represents one of the most complex logistics operations in military aviation. Its parts, training modules, and maintenance tools are spread across dozens of countries. Introducing an F-55 would mean:

Creating an entirely new logistics pipeline

Training new maintenance crews

Manufacturing different spare parts

Updating simulation and flight training tools

In short, it would double the backend burden, driving up costs and potentially reducing readiness in the short term.

Trump’s Track Record on Defense Procurement

Trump has long taken a hands-on approach to defense procurement, even as president. He famously criticized the F-35’s high price tag before taking office, and later claimed credit for negotiating cost reductions with Lockheed Martin. He has also shown interest in modernizing older platforms like the F-15 and F-22, favoring visible upgrades as a sign of strength.

With the F-55 proposal, Trump is once again trying to inject innovation, though critics argue it’s more about branding than engineering. “Calling it the F-55 doesn’t change the math,” one analyst said. “You’re talking about a new plane, not a tweak.”

Final Thoughts: Futuristic or Far-Fetched?

At a time when the U.S. military is racing toward sixth-generation fighters and autonomous air combat platforms, Trump’s F-55 concept may seem out of sync. It’s rooted in a very traditional view of airpower—more thrust, more engines, more noise equals more dominance.

But the future of aerial combat may not follow that formula. Drones, artificial intelligence, and data fusion are becoming just as critical as dogfighting prowess. That raises the question: Should America spend billions on a new twin-engine fighter, or leap ahead with NGAD and unmanned systems?

Conclusion

The “F-55” is an intriguing idea that taps into long-standing desires for redundancy, power, and prestige. But the engineering challenges are immense, the costs astronomical, and the strategic value unclear, especially when more advanced sixth-gen options are on the horizon.

In the end, Trump’s pitch might be remembered more as a political soundbite than a turning point in aviation history. Whether the Pentagon takes the proposal seriously or shelves it as wishful thinking remains to be seen.

FAQs

 1. Why just one engine powers the F-35?

 Designed with a single strong engine (Pratt & Whitney F135), the F-35 balanced performance, cost, and adaptability over several military branches.  Additionally, streamlining maintenance and logistics is a single-engine configuration.

 2. Development of the F-55 would cost what?

 Although there are no official numbers, analysts project it might cost hundreds of billions over decades, the same as the initial F-35 development program.

 3. Could the F-55 actually replace the F-35?

 Contrary to expectations.  Deeply ingrained in U.S. and partner air forces is the F-35. Developed F-55 would probably be considered a different aircraft.

 4. Are two engines truly safer than one?

 From a redundancy standpoint, indeed.  Two engines give a backup should one fail.  Modern engines like the F135 are rather dependable, though.

 5. Will the F-55 be used going forward by the Pentagon?

 Not yet are official plans in place.  Most analysts feel it would be more sensible to concentrate on the NGAD program and current upgrade routes.

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