While this sounds like a silly question I woulds argue that for a low time pilot it is actually a teachable point.
Obviously most trimming involves the elevator, but many new CPL's will not see three axis trimming until they get their first job. I realized this many years ago when watching a new Navajo Copilot fuss with the rudder and aileron trim. The problem is, of course, the fact that rudder and aileron trim affect each other. After watching much fiddling with the trim wheels for a few minuites the light dawned and I realized what the problem was.
Things got much better when I told him to hold the wings level with the control wheel and centre the ball with the rudder trim. Then I got him to trim off the roll pressure. Pretty obvious to someone with some experience aircraft with 3 axis trim, but something not so obvious to a newbe and rather sad it had never been covered in his training.
The real problem was that as part of his preflight he had put all the trims to zero, apparently on the advice of some instructor in flight school fantasy land.
So here is a tip. If you are a new copilot and are preflighting an aircraft that just came in from a revenue flight like this guy was, and you find the rudder trim at 1.5 units right and the aileron trim at 1 unit left wing down, there was probably a good reason for it and maybe you don't want to mess with it.
Anyway after the copilot got the aircraft flying nice and straight guess where what the trim settings were
