Air Commandos from the 1st Special Operations Aircraft Maintenance Squadron look at a step-by-step checklist at Eglin Air Force Base, Fla., March 21, 2017. This checklist was used to bring power to the AC-130J Ghostrider gunship while it underwent its first cold soak, a test done to examine the aircrafts operational competence and resilience in arctic temperatures. (U.S. Air Force photo by Airman 1st Class Dennis Spain)