plans built full size wing tip rib

[sjt]

On the outer full size rib (wing tip) it seems to be correct to cut lightening holes where the nose and center rib would normally have them. My concern is the portion of the rib aft of the rear spar. All of the pictures I see indicate that lightening holes are cut in that area. Why wouldn't that let air flow and whistle thru when the aileron is deflected? If I do not cut them it would be air tight in the fiberglass section.

[John Rheney]

I'm building a 4 place, but I did not cut the lightening holes out of the rear aileron section of the tip rib for that very reason. I did put a angle stiffener in that area just to be sure though.

Best,
John

[sjt]

Thanks for the suggestion of the stiffener. I think I will flush rivet the aileron side. I guess I will stick with the 9/16 flange like the other ribs . As far as I can tell a single row of nutplates are used to fasten a fiberglass tip. I suppose the nut plates must be deformed to follow the contour.

stan