EXCLUSIVE: Pentagon launching competition to replace F-35 cooling system

FARNBOROUGH 2024 — The Pentagon will launch a competition for the overhaul of the F-35’s cooling system, which could see Honeywell Aerospace and RTX subsidiary Collins Aerospace battle for the much-anticipated upgrade, Breaking Defense has learned. 

In response to questions from Breaking Defense, the F-35 Joint Program Office confirmed that it is now planning an open competition for the right to produce the Power and Thermal Management Unit (PTMU), bringing to a head over a year of back-and-forth between contractors and the government about what is the best way forward.

Changes to the PTMU — as well as a separate suite of F135 engine upgrades — are seen as vital for the F-35 in the coming years as it receives a laundry list of hardware upgrades and software updates that will tax the jet’s current power and cooling capabilities. A competition would offer a lucrative contract to an eventual winner, who would provide parts to retrofit likely a bulk of the roughly 1,000 F-35s currently in service and manufacture the upgraded system for future aircraft.

“Contract award for the upcoming phase of the PTMU [Power and Thermal Management Unit] program is expected in Fall 2024,” the F-35 Joint Program Office said Tuesday. “We will work with Lockheed Martin throughout the entire process to ensure all known PTMU solution options are evaluated for performance and economical retrofitability to existing aircraft; bringing maximum capability to the warfighters while accounting for cost.” (The program office did not immediately respond to further questions about the scope of the phase 1 contract.)

The JPO added that its PTMU team conducted “extensive” market research earlier this year and concluded that Lockheed Martin, the prime contractor on the fifth-gen fighter, would integrate the new PTMU capability onboard the F-35. 

Greg Ulmer, vice president of Lockheed’s aeronautics division, declined to comment on whether the F-35 producer would rather lean toward an upgrade for the current system — an approach favored by incumbent Honeywell — or pursue a new architecture such as the solution floated by Collins, stating that the decision would be up to the Pentagon.

“It will be a competitive selection run by the JPO and we’ll help the JPO be informed on the requirements. And then the JPO will make a decision on how to move forward with the PTMU,” Ulmer said during a Tuesday interview here at the Farnborough air show.

So far, two companies have publicly expressed interest in the PTMU overhaul effort, albeit with very different proposals for how to turn down the temperature of the stealth fighter. 

Honeywell builds the F-35’s current cooling system, dubbed the Power and Thermal Management System (PTMS), a single apparatus that combines an auxiliary power unit, environmental controls and emergency power system. Its proposed solution would upgrade the aircraft’s heat exchangers and improve the flow of liquid coolant, but be carried out by moving around parts of the existing system and upgrading key elements — a tactic Honeywell has said could tamp down cost and development risk.

Company officials have said the proposed changes would provide the cooling necessary to offset 80 kilowatts of heat generated by the F-35’s subsystems, an objective set by the JPO. 

“When I think about what puts the F-35 program at risk the most is change,” Honeywell Defense and Space President Matt Milas said in a Tuesday interview with Breaking Defense. “It is so integrated that it just begs the question of, why would we try to change out something that is so integral into the system, when we’re already having all these problems with TR-3, getting to Block 4, [and when] we have potential conflicts all across the globe? Now is not the time where you want to mess with the centerpiece of your defense strategy.” 

Lockheed and the JPO, Milas said, should consider sole-sourcing the upgrade to Honeywell.

Collins Aerospace — whose fellow RTX subsidiary Pratt & Whitney builds the F-35’s engine — has floated a replacement of the current PTMU with a brand new one it calls the Enhanced Power and Cooling System (EPACS). The company invited reporters in January to view a prototype version of the system, which officials said could also hit 80 kilowatts of cooling.

The cooling system works in tandem with the F-35’s engine, and Pratt has said the company has firewalled itself from its fellow subsidiary Collins amid concerns about improper collaboration, most notably raised by Honeywell. 

Henry Brooks, president of Collins Aerospace power and controls said, “A new power and thermal management system is not only critical to the current overall performance of the jet, but it will be essential to enabling future requirements well beyond Block 4.”

No other companies have publicly signaled interest in the program.