The U.S. Dept. of Defense secured full funding in the 2024 Defense Appropriations bill for the F135 Engine Core Upgrade project, underway by Pratt & Whitney to modernize the propulsion system for the F-35 Joint Strike Fighter. The bill provides another $497 million for the F135 ECU, which DoD previously accepted as the plan for preparing the aircraft’s turbofan power plant to support the broader, Block 4 upgrade to the F-35 program.
Last year, the Pentagon awarded $701.9 million to begin the ECU effort. The new ECU funding comes in advance of the detailed design work that will get underway this year.
Funding for the F-35 has become a point of concern for DoD and the jets’ manufacturers and suppliers, with the Biden Administration expected to cut about $1.6 billion of the program’s budget in line with a Congressional budget agreement struck in 2023.
The F-35 is a series of single-engine, Stealth-enabled aircraft deployed for ground attack and combat, and available in three variants. The jets have been in production for more than a decade, and the Block 4 upgrade is focused on modernizing the F-35’s capabilities with electronic hardware and software advances to facilitate dozens of new weapons systems.
The new Block 4 capabilities are planned to be in place in 2029. But, before Block 4 can be implemented, the jets’ core processor and memory will be updated in an effort called Technology Refresh 3 (TR3.)
The ECU is part of the TR3 effort, which Pratt persuaded DoD is the most cost-effective approach to modernizing the F135 engine.
According to the engine builder, the ECU will build on the F-135’s 45,000-lb. thrust, thermal management, and integrated control systems, with “a modular approach to make way for newer hardware and software.”
Pratt reports that the ECU will maintain the existing F135 supply chain and manufacturing network, supporting over 57,000 jobs and 225 suppliers businesses.
