Pentagon awards Pratt $1.3 billion to continue work on F-35 engine upgrade

WASHINGTON — RTX subsidiary Pratt & Whitney has secured a not-to-exceed $1.3 billion contract to continue developing an upgrade for the F-35’s engine, the Pentagon announced Monday evening.  

Known as the Engine Core Upgrade (ECU), the enhancement is expected to boost performance as well as power and cooling for the Pratt-made F135. Monday’s award — issued as an undefinitized action, meaning the Pentagon and Pratt are still working to finalize terms — says that work under the contract is expected to be completed in March 2028.

“This contract is critical to continuing our positive forward momentum on this program,” Jill Albertelli, president of Pratt’s military engines business, said in a statement. “It allows us to continue work in the risk reduction phase with a fully staffed team focused on design maturation, aircraft integration, and mobilizing the supply base to prepare for production.”

The ECU is needed, Pentagon officials say, in large part to head off power and cooling concerns on the F-35. The current F135 engine is already overtaxed by cooling demands, and a suite of forthcoming upgrades known as Block 4 is expected to turn the temperature higher. The engine upgrade is planned to restore engine life that has been lost to heating issues and fully enable Block 4 capabilities, while a separate improvement to the fighter’s cooling system is geared at facilitating features beyond Block 4. 

Pentagon officials last year, somewhat controversially, opted to upgrade the current engine in a sole-source deal with Pratt rather than pursue a wholesale replacement through a competition, reasoning in part that a new engine was too expensive and not compatible with all three variants of the F-35. The ECU, on the other hand, is planned to fit with the fighter’s existing A, B and C models. 

The ECU cleared a preliminary design review in July. Pratt officials have previously estimated the ECU could cost as much as $2.4 billion, and have recently set a target to begin deliveries in 2029. Pratt did not immediately respond to questions about the contract issued Monday.

Engine giants Pratt and GE Aerospace are separately competing to develop a new engine that will power a planned sixth-generation fighter for the Air Force. That engine effort is known as Next Generation Adaptive Propulsion, though the program’s outlook is in question as the service aims to drastically reduce costs for the sixth-gen jet.