The U.S. air force is holding a post-cold war fire sale of used, and unneeded, F-16 fighters. Some 420 early model warplanes are on the block, with about half already sold to foreign nations. This is a one time event, as in the past the U.S. rarely sold warplanes that were still useful, but no longer needed. And in the past, there were few American warplanes that fit that description.