Pratt & Whitney’s F-135 engine, pictured here on the final assembly line. Photo, courtesy of Pratt & Whitney.

RTX‘s Pratt & Whitney has received a more than $1.6 billion U.S. Navy contract for sustainment of F135 engines for the tri-service and international F-35 fighter by Lockheed Martin, the Pentagon said on Nov. 28.

The funds will cover “recurring sustainment support, program management, financial and administrative activities, propulsion integration, replenishment spare part buys, engineering support, material management, configuration management, product management support, software sustainment, security management, Joint Technical Data updates, support equipment management, depot level maintenance and repair for all fielded propulsion systems at the F-35 production sites and operational locations, as well as training for propulsion systems used in [the] F-35 air vehicle,” according to the contract announcement, adding that the contract will also provide “global maintenance services for [the] F135 propulsion system at unit and depot levels, as well as replenishment spare parts.”

Kinda Eastwood, Pratt & Whitney’s vice president of F135 sustainment, said in a company statement that the contract “helps us maintain readiness rates that enable the warfighter to accomplish their critical missions.”

“Looking ahead, the F135 Engine Core Upgrade [ECU] will leverage this sustainment network, providing F-35 partner nations with a proven, cost-effective infrastructure that enhances readiness and ensures seamless support across the fleet for decades to come,” Pratt & Whitney said.

In August, the company received a $2.8 billion Navy contract for Lot 18 F135 engines.

House and Senate appropriators’ versions of their fiscal 2026 defense bills, as in fiscal 2024 and 2025, bar the Defense Department from funding an F-35 alternative engine to the F135.

The Senate appropriators’ bill adds $280 million for F135 spares and $500 million for F-35 sustainment to help address “sub-optimal projected operational readiness rates.”

On Sept. 30 last year, DoD said that Pratt & Whitney had received a received a more than $1.3 billion cost plus incentive fee contract for the F135 ECU.

In fiscal 2024, the Air Force decided to scrap the Advanced Engine Transition Program and move ahead with ECU.