also serves as a training hub for new weather professionals—both enlisted and officers. Other military activities and federal agencies using the base include the Navy Operational Support Center Tucson, a detachment of the Naval Air Systems Command, the Federal Aviation Administration, the U.S. Customs and Border Protection Air and Marine Operations Tucson Air Branch, and the U.S. Army Corps of Engineers. Based units Flying and notable non-flying units based at Davis–Monthan Air Force Base. Units marked GSU are Geographically Separate Units, which although based at Davis–Monthan, are subordinate to a parent unit based at another location. United States Air Force Air Combat Command (ACC) Twelfth Air Force Headquarters Twelfth Air Force 612th Air and Space Operations Center 612th Air Communications Squadron Fifteenth Air Force 355th Wing (host wing) Headquarters 355th Wing 355th Operations Group 354th Fighter Squadron – A-10C Thunderbolt II 357th Fighter Squadron – A-10C Thunderbolt II 355th Operations Support Squadron 355th Training Squadron 355th Maintenance Group 354th Fighter Generation Squadron 357th Fighter Generation Squadron 355th Component Maintenance Squadron 355th Equipment Maintenance Squadron 355th Maintenance Operations Squadron 355th Munitions Squadron 355th Medical Group 355th Aerospace Medicine Squadron 355th Dental Squadron 355th Medical Operations Squadron 355th Medical Support Squadron 355th Mission Support Group 355th Civil Engineer Squadron 355th Communications Squadron 355th Contracting Squadron 355th Force Support Squadron 355th Logistics Readiness Squadron 355th Security Forces Squadron 563rd Rescue Group 48th Rescue Squadron 55th Rescue Squadron – HH-60G Pave Hawk 79th Rescue Squadron – HC-130J Combat King II 563rd Operations Support Squadron 923rd Aircraft Maintenance Squadron Sixteenth Air Force 55th Wing 55th Electronic Combat Group (GSU) 41st Electronic Combat Squadron – EC-130H Compass Call 42nd Electronic Combat Squadron – EC-130H Compass Call 43rd Electronic Combat Squadron – EC-130H Compass Call 755th Aircraft Maintenance Squadron 755th Operations Support Squadron 557th Weather Wing 1st Weather Group 25th Operational Weather Squadron (GSU) US Air Force Warfare Center 53rd Wing 53rd Test and Evaluation Group 418th Test and Evaluation Squadron (GSU) – EC-130H Compass Call and HC-130J Combat King II 57th Wing USAF Weapons School 556th Test and Evaluation Squadron (GSU) – MQ-1B Predator and MQ-9A Reaper Air National Guard Air Force Reserve Command Test Center Detachment (GSU) – A-10C Thunderbolt II Air Force Materiel Command (AFMC) Ogden Air Logistics Complex 309th Aerospace Maintenance and Regeneration Group (GSU) Air Force Reserve Command (AFRC) Tenth Air Force 920th Rescue Wing 943rd Rescue Group (GSU) 305th Rescue Squadron