F-35 TR-3 Upgrades Face Further Delays, Raising Concerns Over US Air Force’s Combat Readiness

Washington, D.C. – The long-awaited operational tests for the F-35 Joint Strike Fighter's Technology Refresh 3 (TR-3) upgrades are now expected to begin in the mid-to-late fiscal year 2026, marking yet another delay in the modernization of the world’s most advanced fighter jet. This comes more than two years after Lockheed Martin started rolling out TR-3-equipped aircraft and at least three years after the originally scheduled test date.

According to the Office of the Director, Operational Test and Evaluation (DOT&E), which submitted its annual report to Congress on January 31, the tests will only commence once the TR-3 software stabilizes and necessary aircraft modifications, flight test instruments, and open-air battle shaping capabilities are in place. However, the office also noted that if these requirements are met earlier, testing could be accelerated.

A Crucial Upgrade Facing Setbacks

TR-3 represents a significant technological leap for the F-35 program, enhancing its computing power, memory, and displays—all necessary to support future improvements, particularly Block 4 upgrades, which will expand the jet’s weapon-carrying capacity, targeting capabilities, and electronic warfare systems. Despite the importance of TR-3, the program has suffered from software development and integration challenges, delaying its combat readiness.

Originally scheduled for release in April 2023, TR-3 faced repeated postponements, forcing the Pentagon to halt the acceptance of new F-35 deliveries until July 2024. By that time, an interim version of the software—sufficient only for training flights—was completed, allowing limited deliveries to resume. However, TR-3-equipped F-35s remain incapable of conducting combat missions.

In a statement to Defense News, Lt. Gen. Michael Schmidt, the Pentagon’s F-35 program executive officer, assured that the program is making progress.

“We are aggressively implementing comprehensive test plans to ensure this critical upgrade delivers cutting-edge capabilities to the warfighter. The F-35 [Joint Program Office] remains focused on working through known risks to deliver TR-3 combat capability in 2025. The capability will continue to be improved in future lots to ensure warfighters have what they need to win in future conflicts.”

However, some within the defence establishment remain sceptical about this timeline. Lockheed Martin’s Chief Financial Officer, Jay Malave, revealed in a January earnings call that TR-3 development might not be complete until early 2026, casting doubt on whether the jet will achieve combat capability next year.

Operational Testing and Fielding Timeline

An official familiar with the F-35 operational test program, speaking on condition of anonymity, emphasized that the testing delays would not impact the fielding of the jets.

“It is not uncommon for fielding decisions to come before operational testing is complete,” the official stated.

This suggests that TR-3-equipped jets could continue entering service even before formal operational testing validates their effectiveness. However, concerns persist over whether this approach might lead to fielding incomplete or underperforming aircraft, potentially affecting combat readiness.

Impact on Block 4 Modernization

Beyond TR-3, these setbacks have cascading effects on the F-35 Block 4 upgrade, a critical modernization effort aimed at keeping the fifth-generation fighter ahead of emerging threats. Block 4 enhancements are expected to introduce:

• Expanded weapons integration, allowing the F-35 to carry a broader range of munitions.
• Advanced sensor and targeting systems for improved threat detection and engagement.
• Enhanced electronic warfare capabilities to counter modern adversary defences.

However, the DOT&E report criticized the F-35 program’s inability to meet software development and testing deadlines, warning that these failures are jeopardizing the entire modernization effort.

“The F-35 program has shown no improvement in meeting schedule and performance timelines for developing and testing software designed to address deficiencies and add new capabilities,” the report stated.

What’s Next?

With the Pentagon, Lockheed Martin, and allied nations relying on TR-3 as the foundation for future F-35 advancements, continued delays threaten to impact combat operations, international procurement plans, and overall fleet effectiveness. While the F-35 Joint Program Office remains optimistic about delivering TR-3 capabilities by 2025, historical trends suggest further delays remain a distinct possibility.

As the F-35 program navigates these challenges, policymakers and defence officials will have to decide whether fielding partially upgraded jets is a risk worth taking—or if further delays are necessary to ensure full operational capability.

For now, the world’s most advanced fighter remains in a technological limbo, awaiting the upgrades that will define its effectiveness for decades to come.