A U.S. Air Force F-35A Lightning II aircraft assigned to Hill Air Force Base, Utah, is refueled by a 100th Air Refueling Wing KC-135 Stratotanker during a flight to Estonia, April 25, 2017. The F-35s participated in a first-ever flying training deployment to Europe, and the forward deployment to Estonia allowed Airmen to better understand NATO's current infrastructure and strengthen interoperability with allies. U.S. Air Force photo by Senior Airman Christine Groening