Honeywell Unveils P40 Upgrade for F-35 Cooling Capacity

Honeywell has announced a significant upgrade to the F-35's Power and Thermal Management System, increasing cooling capacity by 25% in the near term. The P40 system, set to enter service between 2029 and 2030, raises cooling capacity from about 32 kilowatts to 40 kilowatts through software changes and targeted improvements to liquid cooling.

The upgrade responds to rising thermal demand from more capable sensors, mission systems, and onboard processing. Honeywell expects the P40 system to be installed alongside the F-35's planned Engine Core Upgrade, allowing operators to add cooling capacity during an already scheduled maintenance event.

P40 is positioned as the first stage of a phased modernization plan that could eventually increase capacity to 62 kilowatts and beyond. The existing PTMS performs 14 mission- and safety-critical functions on the F-35, including auxiliary and emergency power, engine starting, environmental control, and thermal management.

Honeywell has analyzed nearly 1 million flight hours to identify causes of non-resettable in-flight shutdowns attributed to Honeywell. Corrective measures incorporated into P40 are projected to reduce those events by about 30%.