I asked a Part 121 Fed once what he thought about pilots doing engine run-ups. His response? "You're nuts, there is no way I'd do one". I guess he's seen how the sausage gets made when something goes awry. It's your ticket to lose, and no one else's. Is it really worth 15 minutes of pay? Wasn't it AA who managed to torch a 767 at the gate doing a run-up? I wonder how that all worked out for the crew?

To me, the same thing applies to running one at the gate, without compensation (the door's open) or protection of SOP. While freelancing sounds good, in reality, it's potentially a can of very expensive worms.

We can all find neat ways to skin a cat, but why?
Why leave a hub without an APU when you're headed to MEX in the summer?

Airlines have a lot of tools at their disposal to minimize refusals. Let's all hope that PP is the last one they reach for.