Thanks to a congressional rescue and an 11th-hour change of heart by the Pentagon’s civilian leadership, the contract to develop the U.S. Navy’s next carrier-based fighter is now on track to be awarded by year-end.

Even after the F/A-XX program’s already circuitous 14-year journey, however, the stealthy replacement for the Boeing F/A-18E/F and EA-18G still faces a difficult path to arrive on carrier decks sometime in the next decade.

In addition to navigating yet another budgetary setback, the winning team—led by either Boeing or Northrop Grumman—must navigate a tight set of design constraints.

But simply securing a firm Pentagon commitment to award a contract this year must feel like a victory for F/A-XX program supporters.

A year ago, the program seemed lost. Newly appointed Navy Secretary John Phelan paused the source-selection process almost immediately after taking office. Phelan initially cited a need to review the balance of crewed and uncrewed aircraft in the Navy’s plans for the carrier air wing of the future. He then blamed the decision to pause the program on a loss of confidence that either of the competing teams would deliver the aircraft on time and on budget. Gen. Dan Caine, chairman of the Joint Chiefs of Staff, seconded those concerns, telling lawmakers in June that the defense industry’s “ability to produce” the future fighter was in doubt.

But the program’s support from the Navy’s military leadership and key lawmakers never wavered. Adm. James Kilby, then-acting chief of naval operations, reaffirmed that the requirement for a new carrier-based fighter to fly alongside the Lockheed Martin F-35C remained valid.

“It’s important to continue onward here because, I think, China is not slowing down, and we shouldn’t slow down either,” Kilby told lawmakers last June.

Congress emphatically sided with Kilby’s position. The Navy requested only $74 million in the fiscal 2026 budget plan for the F/A-XX program, saying the funding would be enough for both contractors to complete their designs. Lawmakers, however, decided to insert $1.69 billion for the Navy’s next-generation fighter, including $940 million in regular appropriations and $750 million in the One Big Beautiful Bill Act.

The extra money still tracks below expectations for a new fighter development program at this stage. By contrast, Congress awarded the Air Force $3.45 billion this year to ramp up the engineering and manufacturing development phase of the Boeing F-47, the next land-based fighter in the U.S. inventory. But the approved fiscal 2026 funding for F/A-XX is enough to get the program through the contract award milestone later this year.

The Navy’s commitment to ramp up F/A-XX development after this year remains uncertain. The comparison with the F-47 program is sobering. The Air Force revealed plans on April 3 to request $5 billion in the fiscal 2027 budget to enter the second year of full-scale development for the next land-based fighter. The line item for the Navy’s “next-generation fighter” in the fiscal 2027 spending plan is only $140 million, despite the Trump administration’s historic $1.5 trillion defense spending proposal to Congress.

To keep the Navy program on track, it will likely be up to lawmakers again to add hundreds of millions of dollars or more to the F/A-XX budget account.

The Navy’s performance requirements for the F/A-XX could complicate that development phase. Although the F/A-XX is widely expected to fall short of the speed, range and stealth requirements of the Air Force’s F-47, the constraints of operating from an aircraft carrier still make the Navy’s fighter program challenging.

Among the few performance requirements published by the Navy is a demand for a combat radius that is at least 25% greater than the Super Hornet’s. That suggests that the F/A-XX will be fielded with a combat radius of at least 750nm.

Although well short of the 1,000-nm requirement for the F-47, the Navy specification is ambitious. The Navy confirmed to Aviation Week in 2024 that the F/A-XX will be powered by a derivative of an existing engine, and none of the range-boosting adaptive turbofans is still in development by the Air Force. Further, the Navy lists the weight limit of the catapult and arresting gear for a Gerald R. Ford-class aircraft carrier at 80,000 lb., which sets a fixed cap on the maximum takeoff weight and onboard fuel capacity for the F/A-XX.