Sky Sentry An Air Force KC-135R Stratotanker refuels an E-3 Sentry during an orientation flight at Tinker Air Force Base, Okla., Feb. 25, 2020. SHARE IMAGE: Download Image: Full Size (1.09 MB) Tags: Air Force Photo By: Air Force Senior Airman Mary Begy VIRIN: 200225-F-AO039-9095M.JPG Photo Gallery