Back when I was still on Reddit, I encountered a post saying that they are used in airplane maintenance. They might have specified that their experience was with the military or I might be misremembering that part.
I have no experience in this area and cannot vouch for the veracity of the claim, just wanted to let you know that I have seen something that supports your theory.
edit: Sentences make way more sense when you use the right word and not a completely incorrect one.