Today I came down on a wing tip of my avistar. A few of the rubber bands came loose, but not enough. The wing twisted enough in the saddle to break the leading edge where it meets the airplane. A chunk of balsa is broken away.

I don't know if I have given enough info, but I am wondering if there is any info in general about what would be required to repair the leading edge.

If it is only the leading edge and not the saddle or the spar or ribs of the wing, it should be an easy fix. How damaged is it and how bad is the tip? Is there any broken ribs? You can pull back the covering a little past the damaged area and see what you are up against. If any of the leading edge is intact, try to leave it and square it off for a new piece. Take a piece of balsa a little larger than the damaged area and cut, shape and sand it to fit. I would then epoxy it into place as you cannot be sure the CA would reach everything. Once done check the fit in the saddle and adjust accordingly. Cover the area and go try to land safely again. If possible, make sure a more experienced modeler is at your field when you are ready to fly it, explain to him how you fixed it and let him help you decide if it is flight worthy. [8D]

Good Luck,
Bob

You'll need to carefully check the wing's structure. If the leading edge was damaged, it's possible that there's some damage in the spar joiner area. You'll likely have to strip the covering and look carefully. You don't want to find out at a later date that the center joint was damaged and then have the wing fold in flight.

A 4-inch strip of glass cloth on the bottom of the joint from leading edge to trailing edge would be good insurance after such damage to the wing.

If the damage is minor, just a little balsa filler will do the trick.

I WOULD like to point out here, that although some damage was done, the rubber bands saved you from having a complicated Fuselage repair!

Let this serve as a warning to those newbies who want to bolt their wings on!

Thanks for the input. Another question... how many rubber bands should I have used? I tend to use a total of 12, is the about right? I wonder if I should have had less...

I used 10 on mine and never had a problem. My Avistar took a beating on the leading edge during my training period. I let it go for a while because the monokote was not torn and it still flew fine. I finally took the time to make repairs in 4 areas where the LE needed fixing. Depending on the amount of damage, this may not be the way to go, but it worked for me.

1. I cut out the bay in front of the spar where the damage was. I removed the covering and then cut along the sides of the bay leaving an open area between the ribs.

2. I traced out a pattern of each rib and cut it out of a 3X5 card. Then I transferred the outline to a sheet of balsa that was thick enough to add strength to the ribs one either side. (I made the extra rib just enough smaller to accommodate the leading edge sheeting when it was replaced. You need to leave this space, or you will not match the surface on each side when the sheeting is added.

3. I purchased a piece of leading edge balsa at the LHS and cut it to length between the ribs and glued it into place.

4. I glued in the balsa copies of the ribs on each side ensuring that they lined up with the sheeting on each side. This included checking to ensure that the bottom and tops followed the underside of the sheeting material that was still in place. The ribs also met up with the back side of the LE to help have something to glue to and add strength.

5. Glue another piece of square balsa in front of the spar so that the sheeting has something to glue to when installing.

6. Install the sheeting top and bottom bringing the sheeting out to the point on the leading edge. (I had to glue one into place, trim the front back to the LE balsa, and then installed the other.

7. Sand all parts until smooth and matching both sides, then re-monokote with same color.

I did this same procedure in 4 different bays in the plane and when covered it looked just like new. There may be a much simpler way, but this worked well for me. Of course, I spent about 3 weeks redoing the 4 places, took it out to the field to fly and after 11 flights I hit a bird and the plane was destroyed. I don't even want to know what I paid in time and money for those 11 flights.

I was told by my instructor "If your not crashing your not learning to fly...or your not flying enough"

I crashed my Alpha Trainer...BAD...Took about 16 hours and three trips to the LHS to put it back together. Don't think it's too much for you to do and follow the above instructions.

Remember you can put an engine on a flat piece of wood and it will fly...not very good or under control, anything more is better than that.

Straighten everything, check everything even the clevis you know didn't get damaged. Check the battery compartment very thoroughly as well, I had structural damage and

didn't find it until I was landing...no additional damage done, but it could have been worse.

Good Luck!!

Lefty