While looking for something else, I found this very interesting publication: Mech Magazine (Apr-Jun ‘01), from the US Naval Safety Center.
It’s a bunch of real-life anecdotes about maintaining ships, planes, etc., including tales of things gone wrong and how to avoid them. The anecdote that led me there is “Any Fastener That Fits,” about a set of Milson fasteners on a particular FA-18 access panel. They’re all the same diameter, and look the same when screwed in, but certain fasteners are specified to be shorter than the others.
What happens when you take a bunch of the fasteners out, and then later put a bunch of fasteners back in? If you’re not careful, sooner or later you’ll get some of the short ones in the holes meant for the long ones, which means the panel isn’t secured properly anymore, with potentially disastrous consequences.
(As a systems and usability analyst, I’d add that this is poor design; screws with different lengths ought to be more distinguishable, e.g., with different diameter heads or the like.)
There are a number of other amazing stories of the detail that goes into taking care of the machinery, including a scary one which explains why pilots or mechanics shouldn’t have loose change in their pockets.
Mini-glossary: FOD = foreign object damage; CDI = collateral duty inspector; QAR = quality assurance representative.