can anyone tell me how to patch a L shap tear in my fabric wing?

What kind of fabric is it? Iron on? Best bet is a square patch.

I patched my Cub (covered with 21st Century fabric) by cutting the area out between the ribs (I cut the hole a 1/4" smaller all the way around and the sealed the edge to the side of the rib, then cut the patch 1/2" larger than the hole leaving a 1/4" over lap, sealed the edge with sealing iron on hot and the used a covering iron to shrink the patch. The patch is visible but only when looking for it, came out much better than I thought it would.

thanks i will give that a try don't know what kind of fabric it is but that sounds like that will work