Key Points – President Trump’s recent proposal (May 15th in Qatar) for a new “F-55” fighter, envisioned as a twin-engine “super upgrade” of the single-engine F-35, faces skepticism regarding its strategic necessity and financial viability.
-With the sixth-generation F-47 NGAD already under development, critics argue an “F-55” risks being an expensive and redundant stopgap.
-Transforming the F-35 into a twin-engine platform would necessitate a complete, costly redesign, effectively creating a new aircraft rather than a simple upgrade.
-This announcement, made with defense contractor CEOs present, also raises questions about its political motivations versus sound military and fiscal planning.
The F-55 Fighter Is a Strange Idea
During U.S. President Donald Trump’s recent visit to Qatar, he expressed interest in an upgraded version of the F-35, which he dubbed the F-55.
This new fighter is envisioned as a dual-engine variant of the F-35 Lighting II that will also incorporate a number of new technologies. The F-55 and what Trump called a “Super F-22” would be designed to play a central role in America’s future airpower capabilities.
However, with the development of the sixth-generation F-47 well underway, is it really the best idea to introduce upgrade packages to the two most expensive fighters on the planet?
What is the F-55?
The F-55 is apparently envisioned as a twin-engine evolution of the F-35. The added engine would purportedly address what Trump described as a critical flaw in the current design: its reliance on a single engine. He expressed a clear preference for twin-engine aircraft, saying the would be safer.
While the F-35 has proven itself as a capable and versatile multirole fighter, its single Pratt & Whitney F135 engine has long been a point of contention among military analysts. A twin-engine configuration could theoretically enhance survivability in combat, especially in hostile environments. It could also offer increased thrust, potentially improving speed, climb rate, and payload capacity.
The F-55 would not be a simple upgrade. Integrating a second engine into the F-35’s stealth-optimized airframe would likely require a complete redesign of the aircraft’s structure, avionics, and flight control systems. This makes the F-55 less of a variant and more of a new aircraft, albeit one inspired by the F-35’s design philosophy. However, the question is whether such an aircraft is something the U.S. needs at this time.
What About the F-47?
Meanwhile, the F-47 was supposed to be the centerpiece of the Air Force’s sixth-generation fighter initiative. Developed under the Next Generation Air Dominance program and awarded to Boeing, the F-47 is designed to surpass fifth-generation capabilities. It is expected to incorporate advanced stealth features, AI-assisted piloting, and sensor fusion, along with collaborative combat capabilities that allow it to operate alongside unmanned wingmen. These drone wingmen, such as the YFQ-42A and YFQ-44A, are already undergoing ground testing and are integral to the F-47’s operational concept. If the F-55 is indeed forthcoming, where does this put the F-47?
Is This the Best Use of Resources?
Would the F-55 be a necessary enhancement or an expensive redundancy? While a twin-engine F-35 might offer incremental improvements, it would not be a generational leap in capability. Critics could argue that it risks becoming a costly stopgap between the F-35 and the F-47, one that diverts funds and attention away from more transformative technologies.
Like any Air Force project, the budget must be considered. The F-35 program has already cost over $1.7 trillion over its lifetime, making it one of the most expensive defense programs in history. Developing a twin-engine variant would involve extensive research and development, flight testing, and production retooling, all of which could significantly increase costs and delay procurement timelines. Pursuing an F-55 alongside the F-47 could strain the defense budget and complicate acquisition strategies.
There are also political and industrial dimensions to the F-55 proposal. The announcement was made during a high-profile international visit that included representatives from major defense contractors such as Boeing and GE Aerospace. This has led some observers to view the proposal as politically motivated, aimed at boosting domestic aerospace industries and securing international defense contracts. Lockheed Martin, the manufacturer of the F-35, has expressed support for the idea but has provided few details, suggesting that the concept is still in its early stages.
The Air Force’s New F-55 Question
If a new fighter is in the works, the Air Force would now have to balance an expensive new project with the numerous other highly expensive endeavors currently underway. The purported project is not without its potential merits, however. Proponents would argue that a twin-engine F-35 could provide a valuable bridge between current and future capabilities, offering enhanced safety and performance while the F-47 matures. It could also appeal to international partners who have already experienced the F-35’s qualities firsthand.
On the other hand, the F-55 could be seen as a redundant effort that risks undermining the momentum of the F-47 program. Retrofitting a second engine into the F-35’s airframe would likely require a complete redesign of the airframe, thus resulting in another massive fund-guzzling program. The proposal might reflect a short-sighted desire for incremental improvements rather than a coherent and comprehensive vision for future air dominance.
About the Author:
Isaac Seitz graduated from Patrick Henry College’s Strategic Intelligence and National Security program. He has also studied Russian at Middlebury Language Schools and has worked as an intelligence Analyst in the private sector.
