F-35 Block 4 Modifications Begin; Developments for Block 5 Unveiled
Lockheed Martin Prepares F-35 Block 4 Upgrade, Eyes Future Enhancements
AURORA, CO - Lockheed Martin is gearing up to release the first F-35 Block 4 software updates this summer, with the company and the Joint Program Office already analyzing potential components for Block 5 and subsequent upgrades.
Chauncey McIntosh, Lockheed's vice president and general manager for the F-35 program, revealed that the forthcoming Tech Refresh 3 (TR-3) software release would provide pilots with a substantial increase in stability. McIntosh spoke to reporters at the AFA Warfare Symposium.
Previous issues with TR-3 have been an ongoing concern. In mid-2023, deliveries of F-35s were temporarily halted due to aircraft being built with TR-3 systems prior to full testing. The hold was finally lifted in July 2024, with Lt. Gen. Michael Schmidt, the program executive officer, stating that TR-3-equipped jets were safe to fly following demonstration of less in-flight software reboot necessity.
TR-3 forms the hardware and software foundation for around 80 improvements comprising the Block 4 upgrade. Key features include a high-performance processor, increased memory, and new displays for the F-35, along with other enhancements improving targeting, navigation, communication, and electronic warfare capabilities, as well as enabling new munitions.
McIntosh stated that Block 4 will focus on enhancing sensor upgrades, sensor fusion, and integrating new weapons into the jet. The threat environment is driving continual updates to the roadmap prioritizing Block 4 and later improvements, McIntosh said.
The TR-3 is considered essential for providing the F-35 with the computing resources necessary for future advancements. While this raises questions about future program developments, both Lockheed and the Joint Program Office are studying potential needs for Block 5 and beyond, with priorities likely to shift over time.
Expanded and upgraded sensors and weapons are currently the top priorities for future developments, according to McIntosh. However, capabilities originally developed for the F-22, such as infrared search-and-track systems or low-drag stealth fuel tanks and pylons, have not yet been confirmed for inclusion.
Lockheed is yet to establish specific timelines for Block 5 and later programs, with McIntosh recognizing that some capabilities may move forward from Block 5 to 4, or be deferred to later blocks to allow technology maturation.
McIntosh remained tight-lipped about specific Block 5 and future capabilities, aside from indicating they would represent the most important advancements to maintain dominance over adversaries.
Previous Lockheed statements predict that the company will deliver between 170 and 195 F-35s this year, marking a total of 110 delivered to the US and partner countries in 2024. The F-35 recently surpassed one million flying hours prior to the symposium.
Almost all jets stored during the delivery hold have now been delivered, a company official confirmed. McIntosh did not disclose whether full TR-3 testing and certification would be completed this year, with the JPO predicting it would happen in the fall, and company officials suggesting it might occur in early 2026.
The Government Accountability Office has repeatedly urged Congress to separate Block 4 as a distinct major defense program from the F-35, in order to gain finer resolution on its successes and delays. This measure would help classify significant setbacks in Block 4 as Nunn-McCurdy breaches, rather than allowing them to pass unnoticed due to their low percentage of the overall F-35 cost.
One Block 4 capability already integrated into the F-35 is the Automatic Ground Collision Avoidance System, which saves lives by automatically pulling the aircraft away from potential crashes.
- The Future Enhancements for the F-35 Block 4, as revealed by Chauncey McIntosh, include sensor upgrades, sensor fusion, and the integration of new weapons.
- The Air Force's Space Force is studying potential needs for the Block 5 and beyond upgrades, with a focus on expanded and upgraded sensors and weapons for the F-35.
- The Government Accountability Office has urged Congress to separate Block 4 from the F-35 as a distinct Major Defense Program, a move that would help in classifying significant setbacks and gain finer resolution on its successes.
- The Defense industry looks to technology advancements for the F-35's future, with Lockheed Martin aiming to maintain dominance over adversaries through the most important advancements in Block 5 and future programs.
