Aircraft welders, from what I hear, have to be some of the best out there. Even the guys that work on the skins would have to be very good. In the Northwest, we have WABO certification. You have to be certified to weld a certain kind of metal in one position, or any position, using a specific process. Steel plate certification would be a 1 inch plate, in vertical or overhead position, using a stick welder. Each certification is different, and need to be maintained to get a high paying job around here. One more quarter at the college, and I could have a Welding Certificate degree. I already have two degrees, a job, and that certificate is worthless as a qualification.
And yeah, they make fucking bank. If you put in the time, you'd write your own ticket.