In this Aug. 14, 2012 photo, a ground crew member stands in front of a U.S. Air Force KC-135 Stratotanker, which was built in 1958, at Kadena Air Base on Japan's southwestern island of Okinawa. For decades, the U.S. Air Force has grown accustomed to such superlatives as unrivaled and unbeatable. Now some of its key aircraft are being described with terms like decrepit. (AP Photo/Greg Baker)

Associated Press
In this Aug. 14, 2012 photo, a ground crew member stands in front of a U.S. Air Force KC-135 Stratotanker, which was built in 1958, at Kadena Air Base on Japan's southwestern island of Okinawa. For decades, the U.S. Air Force has grown accustomed to such superlatives as unrivaled and unbeatable. Now some of its key aircraft are being described with terms like decrepit.  (AP Photo/Greg Baker)
In this Aug. 14, 2012 photo, a ground crew member stands in front of a U.S. Air Force KC-135 Stratotanker, which was built in 1958, at Kadena Air Base on Japan's southwestern island of Okinawa. For decades, the U.S. Air Force has grown accustomed to such superlatives as unrivaled and unbeatable. Now some of its key aircraft are being described with terms like decrepit. (AP Photo/Greg Baker)