I use my 10" table saw to cut ailerons out, and then face the wing and ailerons with balsa to take up for the saw kerf. It's always arrow straight, with no wandering like you can get with a knife and straightedge. Just set the blade angle and go. I've also done it on my router table using a 1/8" veining bit -- this is a better choice if you are cutting out a barn door aileron, as you can plunge-cut it to start. Of course for both of these methods you need to use the fence!