OFFUTT AIR FORCE BASE Neb. -- A Boeing E-4B, an airborne command post, flies over the U.S. Navy Blue Angels F-18s during the 2009 Defenders of Freedom Open House and Air Show here Aug. 29 - 30. The E-4B serves as the National Airborne Operations Center for the president, secretary of defense and the Joint Chiefs of Staff. In response to an emergency, the aircraft can provide a highly survivable, command, control and communications center to direct U.S. forces, execute emergency war orders and coordinate actions by civil authorities. U.S. Air Force Photo by Josh Plueger