mooseflier

I recently crashed my super sportster 40 fairly hard and the wing got pretty messed up. I've rebuilt plenty of planes before, but this crash did a pretty good number on the wing and I'm worried about making sure that it's structurally sound once rebuilt. The biggest worry I have is that the trailing edge was snapped in two just past the 3rd rib. Both spars and the leading edge are still intact. The rib from #4 outward, and *behind* the spars and the webbing, are gone, including the trailing edge.

So, my plan is to rebuild those ribs (the back half of each, from the spars to the TE) and the trailing edge. I could re-enforce the joint between the two TE pieces fairly well with some plywood and epoxy, but I'm not sure if it would be necessary to do that with each rib. I'm thinking that wouldn't really be necessary for the ribs... once they're in place and monokoted, the monokote would hold that stuff in place pretty well. What do you guys think?

Also, the left half of the wing came out almost entire unscathed. However, the leading edge we crushed right next to where the body contacts the wing. In fact, it was likely the wing saddle that caused that crunch. Other than replacing that piece of the LE, I really don't think I have to be too concerned about it. Sound reasonable?

Thanks for any input!

Note: I added two pictures... one of the right wing and the other of the crushed LE.

foodstick

While I know I could rebuild that wing, especially if its a constant chord .... I am telling you , you are getting real close to making it a tough call...

That leading edge damage should probably be replaced fro the center of the wing out slightly past the damage. I'd make an angled joint, and put a light ply, or real ply plate behind the outboard joint.

The wing thats blown out shouldn't be to bad unless all those ribs taper down in thickness?

try to NEVER butt joint anything that will carry a load, and back the glued joint with a plate...my buddy always says fish plate..not sure thats the term. The ribs could probably be cleaned up and butted, but put some scrap balsa on the sides of the joint. Actually you could make the new back ribs 1/2 inch longer than needed and glue them all inboard, or outbard of the rib front pieces. They would be offset 1/16th inch but shouldn't be critical.

Also you will probably turn out one wing heavy on this repair, so check lateral balance when done.

I like the expanding gorilla glue, and elmers ultimate for repairs..it ain't pretty but it makes gussets in the joint..also experimenting with how far the glue expands, and runs IS A MUST!

Finding any hidden breaks is critical, do some twisting of the SUPPOSEDLY ok areas..look for hidden fractures, you may even need to cut access holes in some sheeting to repair things.

Its fixable..but its no walk in the park.

RC MANIAC119

My Feedback: (14)

Dude;

Save yourself a lot of time and trouble.......just build a new wing!! That will be much easier

mooseflier

Thanks for the feedback you guys, always appreciated. I am curious though RC Maniac... how could rebuilding the entire wing be easier than rebuilding 1/4 of it? As it is now, I need to cut out about 6 ribs, rebuild the TE and the wing tip and re-coat one half. If I were to rebuild the whole thing it would be much, much more work from my point of view. Not to mention, a lot more money in materials.

Thanks again for the help you guys!

Highflight

My Feedback: (4)

I've rebuilt much worse than that, more for the challenge than anything else.

It's definitely rebuildable and there is no problem building it back strong. The one thing I find that can get out of control during a rebuild, however, is weight. When a rebuild would require too much reinforcing beyond the minimum structure, and it looks like it's going to add some weight more than an ounce or two, I tend to replace and build a new structure.

I've also found out that after a rebuild, it's necessary to treat the part like it never flew before. By that I mean that you need to check everything about it because the most minute amount of twist could change the way it flies, or side to side balance, or the detailed way that an aileron might fit differently... all that and more means that you could have a "different" airplane than the one you had one second before the crash.

RC MANIAC119

My Feedback: (14)

Highflight answered the question!!! Strength, weight, twist/warps and all the leading edge damage area MAJOR factors. Besides...you would be rather surprised at the amount of Hidden damage you will find in the "good" half of the wing, which means you will have to redo the entire center section also! You have to rip it apart just to inspect it.

Sure, you can rebuild it, but with the leading edge damage.....I would rebuild a new...straight...light wing!! But that's just me..........

mooseflier

Ok, thanks for all the input you guys!

My main reason for rebuilding it as is, is saving money. Don't have a lot to blow right now. I can rebuild it for almost nothing, but a new wing kit (or all the balsa) I can't really afford at the moment. I'll struggle through it though and get her flying again soon. Thanks for the advice!

N1EDM

My Feedback: (2)

I'm sure that everyone has a suggestion, but one thing that I do is to get the wing jigged up straight and then try to glue in some of the larger pieces, even if it's not structurally sound. This tricks my brain into the "it's not as bad as I first thought" mode.

Once you get it looking a little bit more looking like a wing, the task doesn't seem so ominous. Just be careful not to glue yourself into a corner where you have to rip your newly-glued structure apart to add bracing.

Just my $.02

Bob