A U.S. Air Force F-15C Eagle aircraft pilot signs off on maintenance forms after preparing an F-15 for short-notice takeoffs at the Keflav?k International Airport in Iceland May 14, 2014, during Icelandic Air Policing.
U.S. Air Force units participated in a NATO-sponsored exercise designed to bolster aerial refueling, fighter aircraft interception and combat search and rescue skills. (DoD photo by Tech. Sgt. Benjamin Wilson, U.S. Air Force/Released). Original public domain image from Flickr