The full hot-life capability of Pratt & Whitney’s F135 engine, used in the F-35 Lightning II, was successfully demonstrated during Accelerated Mission Testing (AMT), in test cell ‘Sea Level 2’ (SL-2) at the Arnold Engineering Development Center (AEDC).
Sponsored by US Air Force Engine Component Improvement Program Office, the test focused mainly on the Conventional Takeoff and Landing engine variant that powers the F-35A model for the USAF. CTOL development represents a key milestone of the F135 program.
Michael Astahoff, chief of the CIP Branch for the US Air Force, stated, “Due to the component commonality across all three F-35 variant engines, the lessons learned will save costs for the entire fleet, including the [other] Services and the non-US participating countries.”
The engine achieved 5,210 total accumulated cycles or more than seven years of operation in 235 days of testing. This is equivalent to approximately 1,200 F-35 missions.
AMT testing is performed to evaluate reliability and maintainability performance of the engine over its life span. The testing is also used to identify potential issues before they are encountered by the operational fleet.
During an AMT, engines accumulate hours under monitored conditions and accrue hours at a faster rate than when operating in the aircraft.
John Kelly, deputy for operations of the Aeropropulsion Combined Test Force at AEDC, stated that on average 55 total accumulated cycles (TACs) were achieved in a single day of testing, with the maximum number of 101 TACs in a day. “That amounts to about 30 sorties in the field,” he said.