Vintage B-25 Mitchell bombers fly over the National Museum of the U.S. Air Force on Wright-Patterson Air Force Base in Dayton, Ohio, April 18, 2010, during a memorial flight in honor of the 68th reunion of the Doolittle Tokyo Raiders. The event commemorates the anniversary of the Doolittle Tokyo Raid, which took place April 18, 1942, when U.S. Army Air Forces Lt. Col. Jimmy Doolittle's squad of 16 B-25 Mitchell aircraft bombed targets in response to the Japanese attack on Pearl Harbor. (DoD photo by Tech. Sgt. Jacob N. Bailey, U.S. Air Force/Released)