Refueling Mission An Air Force KC-135 Stratotanker refuels a Canadian air force CF-18 over Alaska, Oct. 20, 2016, during Vigilant Shield 2017, a training exercise in the high Arctic. Air Force photo by Tech. Sgt. Gregory Brook SHARE: Download: Full Size (1.45 MB) Credit: Tech. Sgt. Gregory Brook VIRIN: 161020-F-OH871-631A.JPG Photo Gallery