The upgrade is designed to provide additional power and thermal-management capacity for F-35 Block 4 weapons, sensors and other systems. It will support all three F-35 variants while maintaining full engine life.
The review examined the detailed engine design, propulsion technologies and aircraft-integration requirements. It also assessed technical risks and the industrial base’s readiness for production and retrofits.
“Completing RRDR is an important milestone that demonstrates the maturity of the F135 Engine Core Upgrade and the progress our team is making to deliver this capability to the warfighter,” said Jill Albertelli, president of Pratt & Whitney Military Engines. “This approach strengthens fleet readiness and provides operators with a proven, cost-effective path to sustain and modernize the F-35 for decades to come.”
Risk-reduction work is funded under a contract awarded in 2024. The effort covers design maturation, aircraft integration, test preparation, engineering and supply-chain readiness.
Pratt & Whitney designed the Engine Core Upgrade around the existing F135 architecture. The modification is intended to retain high commonality with engines already in service.
The company describes the ECU as a drop-in upgrade for newly built and fielded F-35 aircraft. It can be installed during engine production or retrofitted at F135 depot facilities.
“The Risk Reduction Design Review highlighted strong collaboration among our industry and government team, demonstrating a mature ECU design,” said U.S. Navy Capt. Mitch Grant, F-35 Propulsion Program Manager. “The ECU program remains on track to deliver substantially improved readiness and to support F-35 modernization to outpace our adversaries.”
Pratt & Whitney has delivered more than 1,500 F135 production engines to customers across 20 allied nations. The existing global production and sustainment network is intended to support the upgrade’s future introduction.
