I would be a little surprised if most larger GA airports didn't have some rule against bringing your own mechanic. As much as I don't like it, the cities/counties/airport authorities have to have some rules to protect the FBO's that they are charging rent to. Think of it as renting a space at the mall to sell widgets, paying the mall rent, plus a % of gross sales, and in the parking lot a widget vendor sets up and starts selling widgets for a little less than you are with no rent to pay.

I don't agree with the policy, but I understand where it comes from. I bet Atlantic is paying a chunk in rent and fuel flowage fees as well as a % of the service business. I'm sure they have some concerns about liability, which may or may not be legitimate, but it doesn't have make sense for the county to buy it.

All that being said, the FBO is using a formerly un-enforced rule to try to force business their way, it never works, people will just fly somewhere else for maintenance, that's what I do!

you get used to it pretty quick.

and you can buy fuel at your maintenance base as well.