This has brewing since last year where I had lots of BS maintenance and paperwork issues. The last airline to have such a poor relationship that mechanics squawked every issue and took their time fixing it was Eastern Airlines. But Eastern has poor economics, lots of competition, old jets, and other issues. In this case the mechanics see the airline doing well with pilots and cabin crew benefitting and they want their cut before the airline economy takes a downturn. American has oodles of other new jets so they shouldn't be in a backlogged maintenance hole with old jets ala Eastern days.

The 737 Max is a real impact but that has to be solved structurally by canceling flights until the jets return to the fleet. Im hearing October for a real large scale return of Max’s to the skies.