Here is exclusive footage showing how their technicians disassemble an entire U-2 spy plane for inspection. It’s a remarkable feat because every part of the plane gets inspected and repaired or replaced if necessary. That is, more than 40,000 rivets and 1,800 individual parts gets looked at and then gets reassembled for every 4,700 flight hours. This attention to detail is how the U-2 Dragon Lady manages to fly for decades without issues.
https://www.youtube.com/watch?v=EW7M4CDHIes&list=PL15KbAxfKZE2DnUA9RNWn4IJQGR6VsBkF
Source footage courtesy of Lockheed Martin.