The Pentagon’s August release of the F-15EX Eagle II’s selected acquisition report warns that the Air Force’s plan to expand its fleet from 129 to 267 Boeing fighter jets risks unpriced costs, production delays, and obsolescence challenges that officials are still working to quantify.
The expansion from 129 to 267 jets requires increasing production lots from 8 to 12, stretching the program’s timeline years further into the future. According to the acquisition report, this extended run will likely force Boeing to conduct “a major technical refresh” to overcome diminishing manufacturing sources and material shortages that could render key systems obsolete before production ends.
The radar, mission computer, electronic warfare suite, and engines could all require replacement mid-production — a shift the Pentagon describes as “a significant redesign effort.” To manage this risk, the program plans to integrate upgraded subsystems into operational flight program releases scheduled between 2031 and 2035, allowing flight testing and fielding without halting the production line.
Yet the most pressing uncertainty is financial. Program officials stated in the report that they have not yet fully estimated the costs of extending production to 267 aircraft. The Air Force is using government estimates for initial budget sizing while “commissioning formal studies to obtain preliminary cost and schedule estimates from the contractors,” according to the acquisition document. A rapid cost estimation process is underway to inform the fiscal 2028 budget request, but the full price tag remains unresolved.
Production Delays and Parts Shortages Compound the Risk
A strike at Boeing’s St. Louis plant from August to November 2025 has permanently set the F-15EX behind schedule. The acquisition report calls these delays “unrecoverable.” Boeing was contractually obligated to deliver all 12 Lot 3 jets in early calendar 2026, but the company will now deliver only 6 by the end of 2026, the report states.
Critical parts shortages are intensifying the production risk. The most acute shortages include Elbit-made large area displays and low-profile head-up displays for the jet’s glass cockpit, General Electric F110 engines, and Collins-made cartridges for ejection systems. While Boeing stockpiled supplies during the 2025 production halt to cover Lot 1B, the risks remain for future lots. The Pentagon has resorted to borrowing-and-payback agreements with foreign military sales customers to maintain the supply of crucial parts.
The cascading delays are hitting overseas deployment plans hardest. The first Lot 3 F-15EXs, originally scheduled to arrive at Kadena Air Base in Okinawa, Japan, in spring 2026, will not be fielded until at least the first quarter of fiscal 2027. Lot 4 deliveries have slipped even further — from an expected 2026 start to calendar 2028. To catch up, Boeing must increase its production rate to two aircraft per month, roughly double its historical pace of one per month over the past 20 years.
The Air Force is working with the Defense Department’s Business Operators for National Defense team and Air Combat Command to optimize the production schedule and create a bridging strategy that keeps older jets or alternative force structures available until the F-15EXs arrive.
The F-15EX expansion was driven by delays in F-35 modernization upgrades and the Air Force’s decision to recapitalize its aging F-15E Strike Eagle fleet rather than retire those aircraft. Boeing declined to comment on the Pentagon’s concerns raised in the acquisition report. The Air Force did not immediately respond to queries about the findings.
Sources
- Air & Space Forces Magazine — Pentagon report on F-15EX doubling risks, production delays, and cost uncertainties; details on Boeing strike impact and parts shortages.
- MiGFlug Afterburner — Analysis of F-15EX selected acquisition report findings, production lot increases, and obsolescence risks.
- U.S. Department of Defense — F-15EX Selected Acquisition Report (FY2027 President’s Budget), released August 2026, detailing cost and schedule challenges.
