> The 17-ton, non-stealthy F-16 is too difficult to upgrade with the latest software, Brown explained. Instead of ordering fresh F-16s, he said, the Air Force s

> The 17-ton, non-stealthy F-16 is too difficult to upgrade with the latest software, Brown explained. Instead of ordering fresh F-16s, he said, the Air Force should initiate a “clean-sheet design” for a new low-end fighter. It's more difficult to upgrade the F-16 systems than to design a whole new aircraft? I mean, maybe there are other reasons to design a new aircraft, but this doesn't sound like the whole story.