Pentagon spends $241 million upgrading F-35’s engine

The engine maker behind America’s most advanced fighter jet just got a quarter-billion-dollar boost to fix problems with that engine and make it more powerful.

Pratt & Whitney, the company that builds the F135 engine powering every F-35 Joint Strike Fighter, received a contract modification worth up to $240.8 million from the Department of War. The engine has been the source of ongoing frustration for the F-35 program, and this new funding is meant to help solve that.

The F135 is the single engine that powers all three versions of the F-35, the fighter jet flown by the U.S. Air Force, U.S. Navy and U.S. Marine Corps, along with more than a dozen allied countries. As the Pentagon has pushed the F-35 to handle heavier workloads, including running more onboard computers, sensors and eventually new weapons, the current engine has struggled to keep up. The Government Accountability Office and Pentagon officials have both flagged the F135 as overworked and in need of a serious upgrade for years.

This new money is meant to push that fix forward. Specifically, it funds engineering work to mature what’s called the engine’s “core upgrade,” essentially a more powerful, more efficient version of the F135’s guts. The contract moves that upgrade out of the design and planning phase and into actual engineering and manufacturing, the stage where a real, buildable engine starts to take shape. Part of the funding also covers building a spare test engine to support that work.

The money comes from three different pots. The U.S. Air Force is putting in $87.6 million. The U.S. Navy is matching that with another $87.6 million. And America’s F-35 partner countries, the allied nations that helped fund and now fly the jet, are chipping in $39 million more.

The work itself will happen across eight different U.S. locations. Most of it, 53 percent, stays at Pratt & Whitney’s home base in East Hartford, Connecticut. Another 15 percent goes to Indianapolis, Indiana, with smaller shares split between Connecticut, Florida, Maine, Illinois and Puerto Rico. The Pentagon expects the work to wrap up by March 2028.