In the new 3" wingtips I built I installed 0.016 2024 T3 stiffener plates at the aft end to close the opening outboard of the ailerons with the mounting flanges turned outboard (into the wingtip) and mounted them with pop rivets. Thus, the tip side wall is flush with the opening instead of recessed. This has worked well and would appear to reduce drag. Using other methods and materials I plan to "flush up" the end recesses in all of the control surface end openings. I'm sure this has been done. Any observations or experience comments?
Bob Axsom
Bob Axsom