In recent times, the President of the United States, Donald Trump, has made a change by asking for the development of a twin-engine version of the F-35 that he would rename F-55. This request has generated a lot of interest and queries among the defense community regarding the next aircraft program of the U.S. Air Force
During a roundtable with business executives in Doha, Trump branded the idea as an “upgrade beyond super” of the F-35. He doubted the value of single-engine fighters while praising the significance of safety through the use of spare systems. To add to it, he even went on to talk about an “F-22 super,” a next-gen Raptor variant, suggesting that he was not only breaking but also rewriting the history of American fighter development strategy.
Trump’s idea of F-55 would essentially be a revision of the F-35 aircraft with two engines instead of one,e whi, in his opinion, would extend the aircraft’s capabilities to a large extent. The logic of his line of thinking is simple: there is no such thing as a bulletproof engine, and therefore, the presence of multiple engines is what gives the aircraft the highest level of safety. To demonstrate how the concept of redundancy in aviation is applied, Trump cited the example of a Boeing,g 74,7 which is equipped with four engines.
The response from the defense and aerospace community has been guarded, if not skeptical. Former Air Force Secretary Frank Kendall called the proposal “mystifying” since a twin-engine version of the F-35 would nearly need to be redesigned.
Aerospace analyst Richard Aboulafia was more direct, calling the proposal “not feasible” and likening it to a child’s drawing instead of an actual engineering proposal. Putting in a second engine basically would create a whole new plane, with all the expenses and engineering challenges that come along with it.
Technological challenges are very real. As J.J. Gertler of the Teal Group explains, the F-35’s existing airframe does not have space for a second engine. Redesigning it would involve a greater, stronger frame, new wings, tail, and air intakes, in effect building an entirely different airplane with minimal connection to the original.
Stacie Pettyjohn of the Center for a New American Security further noted that stealth would be especially difficult to maintain, as even slight alterations in the airframe’s shape or material would destroy low observability.
Strategically, the timing and logic of the proposal are questionable. The Air Force already chose the F-47 as its sixth-generation fighter, built from the ground up to replace future operational requirements. Building a twin-engine F-35 may duplicate the mission profile of the F-47, risking redundancy in terms of size, cost, and capabilities.
In addition, the F-35 program itself is already being heavily modernized and upgraded in terms of sustainment. Multi-billion-dollar upgrades are in the pipeline for engines, thermal systems, and power systems, while the Block 4 upgrades offer increased combat capability. Lockheed Martin has also floated a “fifth-generation-plus” variant of the F-35, providing much of the F-47’s future capabilities at lower cost. Yet the program still leaves unanswered questions about sustainment, maintenance responsibility, supply chains, and intellectual property, highlighting the sheer complexity of such a bold fighter program.
For the defense sector, Trump’s remarks are a mixed message. An interest in purchasing and modernizing the F-35 and F-22 might prove helpful to Lockheed Martin and its partners. Yet the technology and strategic difference between the F-55 concept and current modernization plans means that the undertaking is not likely to go further than the concept phase. Aboulafia cautioned that firms pursuing such an effort without government support would be assuming giant, perilous expenses.
The F-55 debate emphasizes a key conflict in U.S. airpower strategy: reconciling the aspiration for aggressive, paradigm-shifting capabilities with technical constraints, cost, and strategic unity. As the Pentagon presses forward to modernize its fighter force and close the F-35’s sustainment issues for the long term, the F-55 reminds us that visionary concepts have to be anchored in technical possibility and workable planning.