Once upon a time, many years ago, I boarded a Delta jet at SFO somewhat early. I had a seat on the aisle in an emergency exit row. I was just making my nest when three Delta employees showed up and asked the lady in the row across from me if she would mind getting up for a few minutes. She got up and they proceeded to open the exit door (it was a lot heavier than I would have thought) and all get out on the wing. They stood there looking down at a small access door about six to ten feet out from the fuselage and then one of them, presumably the mechanic (engineer to non U.S. readers), took a roll of duct tape (aka speed tape) out of his overalls and proceeded to carefully apply tape along the edges of the door, overlapping both the door and the wing. He stood up, the other two (presumably an inspector and a supervisor) nodded their heads, and they all clambered back inside. It took a little jiggling and manhandling to get the door back in place but they did, thanked the lady, and departed the airplane. Passengers kept boarding through all of this.
The folks on that side of the jet kept the rest of us informed as to the condition of the duct tape all the way to Dallas...