I meant that it's how I determine if it's thrust or rudder (not just a rudder check . . sorry not very clear there ). If it's deviating early in the vertical, it's probably rudder . . if it's later then it's thrust. It's an ongoing process of checks really . . and I usually check things every few flights to make sure nothing has changed. It's amazing how much of a schedule is affected if something goes out [:'(] !

Naturally, "eyeball" the rudder from the top and back as it it should look inline with the fin . . it's the starting point. If the plane is built true, it should be fairly right straight off with only a couple of 'clicks' to get it sorted.

JB