The easiest way to fix the problem is:

1. Disconnect the pushrod from the control horn on the affected/problem surfaces.

2. Make sure the gap and covering surfaces are ABSOLUTELY CLEAN AND FREE OF OIL. Clean the gap and surrounding areas TWICE using rubbing alcohol and a CLEAN cloth/paper towel for each cleaning.

3. Depending on your skill level and if you have the proper tools you can either cut strips of matching covering (Hobbico uses MonoKote on their ARFS ) about 3/4" - 1" wide. Fold the strips in half lengthwise (dull side out ), flex the surface as far as it will go, then insert the strip in the opening (many people just seal the bottom only) and seal it down with a TRIM iron. You can use a regular iron, but for this it is a bit clumsy.

If you don't have an iron (or don't want to do it with monokote strips, disconnect the control rod as mentioned above, flex the surface as far as it will go and use 3M brand "Magic" scotch tape. This tape holds very well and will blend in and be hardly noticeable. While not absolutely necessary, I would tape both sides of the hinge gap.