Are you drilling through tapered ailerons? Keep in mind that a drill press will not help you on tapered stock unless you shim the tapered end so that the drill travels through the material perpendicular to the center line of the aileron. I mark the holes position with a Sharpie Ultra Fine Point then start the hole with a pin so that the drill doesn't wander. Another method is to use a very small straight bit screw driver and just spin it back and forth between you fingers. I used this technique for years. The small driver in the Stanely jeweler's screwdrivers worked great.