The F-15EX, built by Boeing, is an advanced version of the F-15E Strike Eagle and is intended to replace older aircraft while adding fighter capacity. The Air Force had previously said it needed both F-15EX and F-35A aircraft to maintain a balanced fighter force with different weapons loads and operational roles, including in a potential Pacific conflict.
Lt. Gen. David Tabor, deputy chief of staff for plans and programs, told the Senate Armed Services air-land subcommittee that delays involving the F-35’s Technology Refresh 3 and Block 4 upgrades influenced the decision. “As we encountered some slowdowns in deliveries of F-35s due to the previously discussed TR-3 and Block 4 upgrade issues, it became apparent to us that we needed another fighter capacity,” Tabor said.
“This, in conjunction with a lot of the work that has been done in force design and the capabilities of the F-15 and what that provides to us in the pacing challenge, [or China,] made it a very obvious choice,” Tabor added.
Tabor said the existing F-15EX production line also contributed to the decision because it gives the service a way to begin replacing some older F-15E aircraft. “So, that all kind of came together to lead to this decision,” he said.
The Air Force initially planned to buy as many as 144 F-15EXs when it awarded Boeing the first contract in 2020. Since then, procurement forecasts have shifted several times, falling to 80 aircraft, then rising to 104, 129 and now 267.
Tabor said the earlier plan for 104 F-15EXs was based on replacing aging F-15C aircraft at Air National Guard bases. He described that number as a limit “we kind of artificially held ourselves to.”
Delivery of the F-15EX has also faced delays, including effects from a monthslong strike in 2025 at Boeing’s St. Louis facility, where the aircraft is built. Those delays have contributed to operational adjustments, including the temporary deployment of F-22 Raptors to Kadena Air Base in Japan while the base awaits its permanent F-15EX aircraft.
Tabor said the Air Force, the Pentagon and Boeing are now negotiating ways to accelerate F-15EX production. The goal is to increase output as much as possible while supporting the expanded fighter procurement plan.
Lt. Gen. Luke Cropsey, military deputy to the Assistant Secretary of the Air Force for Acquisition, Technology and Logistics, said Boeing is not yet producing two F-15EXs per month on its single production line as required under contract. He said the Air Force is discussing with Boeing how to reach that production rate.
Cropsey said Boeing has presented “a well thought-out plan” to reach two aircraft per month. He added that the company also has a roadmap to eventually produce three or four fighters per month through additional infrastructure and capital investments in St. Louis, including one or two added production lines.
“From an acquisition standpoint, we’ve got some work to do ahead of us to be able to get to the ramp rates that we’re talking about,” Cropsey said. “But I think Boeing is actively in good faith working with us to figure out what that would look like.”
