The revised plan covers 266 production fighters and two development aircraft. The baseline approved in June 2024 included 96 production aircraft and two development jets.
The increase reflects 21 aircraft funded through fiscal 2024 supplemental appropriations and one aircraft added by Congress for fiscal 2026. The fiscal 2027 budget request adds another 148 aircraft through fiscal 2031.
Under the new profile, the Air Force would procure 24 F-15EX Eagle II fighters in fiscal 2027 and another 24 in fiscal 2028. Annual purchases would then rise to 28 aircraft in fiscal 2029 and 36 in each of fiscal 2030 and fiscal 2031.
The expansion would turn what had been a smaller replacement programme into a long-term production run for Boeing and its suppliers. It would also give the Air Force a much larger fleet to replace F-15C and F-15D aircraft that face structural risks, wiring problems and obsolete components.
Procurement accounts for almost $35 billion of the revised acquisition estimate, while research, development, testing and evaluation would total $1.93 billion. The average procurement unit cost is projected at $131.6 million in then-year dollars, or $99.2 million in constant fiscal 2020 dollars.
Despite the sharp increase in the programme’s overall value, its average procurement cost remains broadly flat in constant-dollar terms. The report estimates a decline of 0.05% from the previous baseline, reflecting the effect of spreading programme costs across a much larger fleet.
For Boeing, the additional Air Force aircraft would extend the outlook for its F-15 production line. A separate Israeli order for 25 F-15IA fighters, with options for 25 more, is expected to support production beyond existing U.S. contracts and provide greater stability for lower-tier suppliers.
That industrial outlook, however, rests on a production system already running behind schedule. Boeing must increase output to two aircraft a month to meet delivery requirements for Lot 4 and subsequent batches.
As of April 14, 2026, the company had delivered 18 F-15EX Eagle II aircraft against a contractual requirement for 33. A 15-week strike at Boeing’s St. Louis facility in 2025 halted production, and the company subsequently struggled to meet recovery targets.
Those delays are expected to push the programme beyond its July 2027 threshold for full operational capability. The aircraft tied to that milestone is now forecast for delivery in early 2028, prompting the Air Force to prepare a formal schedule rebaseline.
The larger production run also creates a longer-term engineering challenge. Extending procurement through Lots 9 to 12 will require a major redesign involving a new radar, mission computer, electronic warfare suite and engines as existing systems become obsolete.
The programme did not yet have an approved cost assessment for the additional aircraft and redesign work when the report was prepared. Initial budget planning is based on government estimates while contractors develop preliminary cost and schedule projections.
Supply-chain pressure remains another source of risk. The report identifies large-area displays, low-profile head-up displays, GE engines and Collins Aerospace cartridge- and propellant-actuated devices among the components that may affect future deliveries.
Operating and supporting the expanded fleet through 2070 is provisionally estimated to cost $140.67 billion in then-year dollars. The report described that figure as a very rough estimate and said a more detailed assessment was still being prepared.
The two-seat F-15EX Eagle II is derived from the F-15QA developed for Qatar and incorporates Air Force-specific electronic warfare systems and mission software. It is intended primarily for defensive and offensive counter-air missions as the service replaces its ageing F-15C and F-15D fleet.
