I had a slight incident with my Avistar and my main wing's leading edge, (damn safety fences and T posts). I damaged or actually broke the leading edge of the wing between two ribs. The damage only goes back into the wing about 3/4" from where the leading edge was. I replaced that section of the leading edge with some leading edge stock I got at the lhs. The wing has thin sheet balsa over the leading edge and goes back maybe 4" on the top and bottom of the main wing. Do I need to fabricate a piece of sheet balsa to replace the damaged portion, or can I just put some packing tape over the damaged area and fly. Other than not looking pretty the wing does appear to be in good shape, with no damage to the main spar.

IMO, I would replace the sheet balsa if it was my airplane.
That is up to you. If it is near the tip of the wing you will be safer but if it is closer to midwing or in from there structual support is even more critical.
Check your lateral balance after repairs.

All of the damage is at the leading edge tip of the wing. The damage goes back from the leading edge maybe 3/4".

the leading edge sheeting is used more to shape the airfoil than for structural strength. If you don't mind the packing tape look, you will be ok.

If you don't replace the sheeting, or at least smooth the hole out, it will leave a concave indent when you recover it. I wouldn't trust packing tape, it'll melt when you recover. I'd cut another piece of sheet and CA it in.

Here is a nice article on sheeting repair.

http://www.rcuniverse.com/magazine/a...?article_id=98

Thanks for the link. I wasn't sure how I was going to attach the new sheeting to just the exposed edges that were damaged

Run the grain the same as the original so that it will bend properly. If cross-grain it will not bend right. This applies to the support strips and the patch itself.

sand - fill - sand again - cover - done