RTX says F135 Engine Core Upgrade moves closer to production, adding power and cooling for F-35 Block 4 weapons and sensors

Pratt & Whitney completed a risk-reduction design review for the F135 Engine Core Upgrade, moving the programme closer to detailed development and eventual production for the F-35 fleet. The upgrade is intended to provide additional power and thermal-management capacity for Block 4 sensors, electronic-warfare equipment and weapons while retaining the existing F135 architecture. Completion of the review confirms design maturation rather than production authorization; further engineering, testing and programme decisions remain necessary before fielding. The planned approach is designed to support all three F-35 variants without replacing the aircraft's propulsion system wholesale.