RTX (NYSE: RTX) subsidiary Collins Aerospace has successfully completed altitude testing of its Enhanced Power and Cooling System, known as EPACS, a next-generation power and thermal management platform.
The system is designed to deliver significantly increased cooling capacity to meet the evolving demands of advanced mission systems aboard the F-35 fighter jet and future aircraft.
EPACS is built to provide the critical thermal margin required to support planned technology upgrades, ensuring the F-35 remains operationally competitive throughout its entire service lifecycle.
Altitude testing represents a crucial step in early development and risk reduction for any new power and thermal management system, pushing hardware to its operational limits.
During the testing phase, the system was run for several days at power levels specifically designed to replicate real-world mission requirements across various altitude conditions.
Engineers collected performance data and demonstrated that EPACS can deliver the emergency power output expected during actual flight operations, while also validating the system’s performance models.
Ira Grimmett, vice president of Environmental and Airframe Control Systems for Power and Controls at Collins Aerospace, said the results mark a major step forward for the program.
“Successful altitude testing validates system performance in real-world flight conditions,” Grimmett said. “Completing this phase of testing advances EPACS maturity and reinforces confidence in the system’s capability and performance.”
This latest milestone follows Collins Aerospace’s announcement in 2025 that EPACS had met requirements for aircraft integration, reflecting steady progress in the program’s development timeline.
Collins Aerospace employs approximately 80,000 people and is focused on delivering technologies that advance sustainable and connected aviation, passenger safety, mission success, and space exploration.
Parent company RTX, headquartered in Arlington, Virginia, reported 2025 sales of more than $88 billion and employs more than 180,000 people globally across its aerospace and defense operations.
RTX continues to position Collins Aerospace as a central player in next-generation defense platform development, with EPACS representing a significant investment in the long-term capability of the F-35 program.
