Air Warfare

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

The competition sets up a showdown between incumbent supplier Honeywell Aerospace and competitor Collins Aerospace.

F-35A Demo Team at Warriors over the Wasatch Airshow 2024
A U.S. Air Force F-35A Lightning II assigned to the F-35A Lightning II Demonstration Team performs a practice aerial demonstration prior to the Warriors Over the Wasatch Air Show at Hill Air Force Base, Utah, on June 28, 2024. (U.S. Air Force photo by First Lieutenant Nathan Poblete)

UPDATED at 4:20 PM ET with clarification from Lockheed Martin on structure of PTMU competition.

FARNBOROUGH 2024 — Lockheed Martin will launch a competition to overhaul 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 Lockheed is now planning a 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, the prime contractor on the fifth-gen fighter, would integrate the new PTMU capability onboard the F-35. 

Greg Ulmer, 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, but told Breaking Defense in a Tuesday interview that it would be a “competitive selection.” 

In a later statement provided to Breaking Defense, Lockheed said it will “evaluate all solution options and determine the best path forward in terms of capability and cost to meet the F-35’s future mission requirements. We expect contract authorization from the Joint Program Office this fall, allowing down-select, development and deployment to new and fielded aircraft.”

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 and a test run, which officials said showed 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.