The B-17F Memphis Belle is shown in an undated photo with its clear plastic nose cone visible. (U.S. Air Force photographs via Associated Press)
Jason Davis re-skins the wing tips at the Memphis Belle restoration at the National Museum of the U.S. Air Force in Dayton, Ohio. (Associated Press)
The B-17F Memphis Belle is shown in the restoration hangar at the National Museum of the U.S. Air Force in Dayton, Ohio. The most celebrated American aircraft to emerge from World War II is undergoing a loving and fastidious restoration. (U.S. Air Force photographs via Associated Press)
FILE - This undated file image provided by the U.S. Air Force shows the X-37B spacecraft. The unmanned Air Force space plane steered itself to a landing early Saturday, June 16, 2012, at a California military base, capping a 15-month clandestine mission. (AP Photo/U.S. Air Force, File)
FILE - This undated file image provided by the U.S. Air Force shows the X-37B spacecraft. The unmanned Air Force space plane steered itself to a landing early Saturday, June 16, 2012, at a California military base, capping a 15-month clandestine mission. (AP Photo/U.S. Air Force, File)
Staff Sgt. Marie Martinson, one of two female bomb techs in the 88th Air Base Wing Explosive Ordnance Disposal unit at Wright Patterson Air Force Base in Ohio, is seen here in Afghanistan with a robot pack beside her. (U.S. Air Force)
This Nov. 17, 2010 photo provided by the U.S. Air Force shows an aerial view of the F-22 crash site located approximately 100 miles north of Anchorage, Alaska. An Air Force official says evidence found at the remote, rugged Alaska site where an F-22 Raptor crashed indicates the pilot died, Friday, Nov. 19, 2010. (AP Photo/U.S. Air Force,Master Sgt. Jeremiah Erickson)
Retired Master Sgt. Ed Horton honors the memory of retired Lt. Col. Horrace Crouch by turning his goblet upside down in 2006. The tradition honors Raiders who have died since the last reunion. (U.S. Air Force)
The F-16 Falcon has been a mainstay in the U.S. Air Force arsenal, but the jet fighter and other types of tactical aircraft are being retired by the service for reasons of age and pressure to meet budget-cutting demands. (Associated Press)
