A U.S. Marine Corps MV-22 Osprey tiltrotor aircraft from Marine Helicopter Squadron 1 (HMX-1) flies en route to the Pentagon in Arlington, Va., July 29, 2014. The First Sea Lord and Chief of Naval Staff of the British Royal Navy, Adm. Sir George Zambellas, not shown, was onboard as part of the Commandant of the Marine Corps' Counterpart Program, which invites foreign military leaders to visit the United States and interact with U.S. military leaders. (U.S. Marine Corps photo by Cpl. Michael C. Guinto/Released)