Hi Bidule,

Incidence meters are useful to align the wing to the tail and could, perhaps, be used to check if a wing is warped, but that's not the main purpose.

You can avoid warped wings when building if you ensure, at every step of the way, two things:-

1/ When the plans ask for the wing to be pinned to the flat building board, you continuously check to see if all ribs, etc are doing just that.

2/ Keep in mind what might happen to the structure if an off-centre load is being applied. By that I mean when starting to sheet the leading edge, or gluing one side of the two trailing edge sheets. I find placing weights on a long steel ruler over the main spar is useful when gluing either the leading or trailing edges in place.

Whatever caused it, the fact that it's possible to trim it out in flight with the ailerons means the warp is not particularly severe, and, has been said before, it can be taken out with the use of the heat gun on the covering and a pair of helping hands to carefully twist the structure. Do one side, then let it cool, then do the other side. For some reason, that seems to work best. Bear in mind though, that you are inevitably introducing a stress in the structure which might, over time, relieve itself (especially in hot weather) and the warp might tend to return. Just check occasionally at the flying field.

Hope all that helps; and good luck! It's a great plane to learn aerobatics with.

-David C.