The thermal test program for the Pratt & Whitney F135 propulsion system for short takeoff/vertical landing, or STOVL variant, of the F-35 Lightning II was successfully completed in mid October. The high temperature margin test that took place at Arnold Engineering Development Center at Arnold AFB, Tennessee, involved intentionally running the engine to turbine temperatures beyond design conditions while simultaneously operating the turbomachinery at or above 100 percent of design conditions. The purpose of this test is to demonstrate design margin at the most extreme operating conditions. The test also demonstrated the F135 propulsion system’s ability to produce margin relative to thrust. The test engine produced twenty-eight percent more thrust than the specification requirement.
