The Pentagon is facing further delays and cost uncertainties in its efforts to modernize the F-35 fighter jet, with the completion of the Block 4 upgrade now projected for 2031 at the earliest, a five-year slip from the original timeline. This comes as the Department of Defense (DoD) scales back the scope of the modernization, a congressional watchdog agency revealed.
New Setback for Critical Upgrade
A new Government Accountability Office (GAO) report indicates the latest delay, pushing the completion date two years further than the previous estimate of 2029 released in May 2024. A congressional mandate in 2023 led to the reorganization of the F-35’s Block 4 modernization and Technology Refresh 3 (TR-3) into a new subprogram, intended to address rising costs and schedule overruns.
Fewer Capabilities, Unclear Costs
„According to program officials, the new Block 4 major subprogram will have fewer capabilities, will experience schedule delays, and will have unknown costs until the program office finishes developing its cost estimate,” the GAO stated. The specific capabilities that will remain part of the subprogram are set to be finalized in acquisition planning documents expected in the fall of 2025.
Engine Delays Compound Problems
Technologies dependent on upgrades to the F-35’s engine and power management system will be deferred, as the F135 engine core upgrade is not expected to be in production until at least 2031. Post-Block 4 capabilities reliant on these engine upgrades are now projected to be delivered in 2033, further extending the timeline.
Cost Estimates Remain Elusive
An updated cost estimate for the Block 4 effort, previously valued at $16.5 billion in 2021, is anticipated „later in 2025,” according to the GAO.
GAO Expresses Cautious Optimism
Despite the challenges, the GAO expressed cautious optimism that the Block 4 subprogram will provide improved insight into cost, schedule, and performance, enabling more informed decision-making.
Contractor Assurances
Lockheed Martin, the F-35’s prime contractor, stated its commitment to delivering at least 170 F-35s in 2025 and continuing to field Block 4 capabilities to maintain the aircraft’s dominance.
Delivery Delays Persist, Incentive Fees Questioned
However, both Lockheed Martin and engine manufacturer Pratt & Whitney continue to struggle with on-time deliveries of aircraft and engines. The GAO criticized the use of incentive fees, which reward contractors even for late deliveries.
Incentive Fees Under Scrutiny
The GAO recommended a reevaluation of incentive fee structures to ensure they effectively drive performance gains. The existing Lot 12-14 contract allowed Lockheed to deliver aircraft up to 60 days late while still earning a portion of the fee. “The F-35 program’s use of incentive fees has largely been ineffective at holding the contractors accountable to delivering engines and aircraft on time,” the GAO concluded.
Implications and Future Outlook
The continued delays and cost uncertainties surrounding the F-35 modernization program raise concerns about the long-term viability of the platform and its ability to meet evolving threats. The restructuring and scaling back of the Block 4 upgrade may impact the F-35’s future capabilities and necessitate further investments to address emerging technological advancements.
