A Pratt & Whitney F135 engine hangs in Arnold Engineering Development Complex (AEDC) Sea Level Test Cell 3 at Arnold Air Force Base, Tenn., between test runs Sept. 2, 2021. The F135, used to power the F-35 Joint Strike Fighter, is undergoing Accelerated Mission Testing in the AEDC facility in support of Component Improvement Program efforts. (U.S. Air Force photo by Jill Pickett)