I'm not doubting that... but my question is have you ever corrected an error of a coworker?
.
And have you seen work that has been incorrectly done by any other US mechanic, including that done by a mechanic at another airline?
.
And do you think that DL runs a good maintenance operation and is able to correct whatever problems might exist with its aircraft regardless of whether they are a result of aircraft that have problems in service or as a result of problems with repairs either from DL mechanics or something from outsourced mechanics.
When we did our overhauls, it was routine for the airplane to return from its verification flight with a clean log book. I have personally gotten airplanes from our wonderful outsourced overhaul facilities that come straight from them to us and had to work a dozen items before we could put the a/c back into service. Th MD88's are the worst.
We did them faster and better. End of story.
Do our mechanics make mistakes? Of course, we are all human, but in the end we turn out a much superior product.