110809-F-YX459-164

A pair of Russian air force Su-27 Flanker fighter aircraft escort a simulated hijacked airliner during the second day of flight operations for exercise Vigilant Eagle Aug. 9, 2011, over the Pacific Ocean. The Russian fighters followed and monitored the aircraft while it was in Russian airspace, handing it over to U.S. F-15 Eagle fighters from Elmendorf Air Force Base, Alaska, when it entered U.S. airspace. Vigilant Eagle is an annual joint anti-terrorism exercise between the Russian air force, the Federal Aviation Administration and the North American Aerospace Defense Command that trains personnel to respond to an air terrorism threat that crosses international boundaries. (DoD photo by Tech. Sgt. Thomas J. Doscher, U.S. Air Force/Released)