Two Air-Defense Fighter F-16A Fighting Falcons from the North Dakota Air National Guard’s 178th Fighter Squadron lead an F-15C Eagle from the 27th Fighter Squadron at Langley Air Force Base, Va., in formation during a combat air patrol mission in support of Operation Noble Eagle. More than 11,000 airmen -- the majority Air National Guard and Air Force Reserve -- have generated more than 7,500 sorties to patrol American skies 24/7 since Sept. 11, 2001. (U.S. Air Force photo by Staff Sgt. Greg L. Davis)