Don’t trash that crash!

Jul 16, 2012 13 Comments by

We’ve all done it. That one dumb thumb move, the very brief moment when our brain wanted to go right and our thumb decided to go left. There’s nothing you can do but pick up the pieces and take them back to the shop. Some professional aircraft impact testers even have a trash bag in their flight box for damage retrieval. The first rule of crash repair is to pick up all the pieces, but once you have all the parts home, what’s next? Let’s look at one of the more common impacts, wing damage. This type of damage can happen anywhere and is perhaps one of the more common repairs. Let’s see how we can repair this wing and get back into the air by the next weekend.

YOU’LL NEED

Here are some of the tools and repair supplies you may need for your repair. You won’t use all of these every day, but you’ll need many of them every time. Supplies include CA glue, accelerator, epoxy, heat-shrink film, scissors, mixing sticks, tape, iron, trim iron, #11 hobby blade, pliers, reinforcement material (fiberglass) and extra balsa.

1 DAMAGE

Here is the damage to the wing that needs to be repaired. Fortunately, most all of the parts are still inside the wing because the covering held together.

2 INSPECTION

Cut around the damaged area and leave the covering attached to any rib that can still support it. Inspect the damage inside and remove the broken parts to use as templates. Here the center rib is damaged beyond repair, but the adjacent ribs can be used as a base part to which I can glue the new ribs.

3 MAKING THE TEMPLATE

By piecing the part together, I was able to make enough of a rib to make my first template. After checking the fit, I needed to make another template until I got one that was just about the right size. The right size is one that is just a tiny bit large, so it can be reduced in the next step.

4 FINISHING THE TEMPLATE

After getting a piece that is slightly larger, I sanded to fit. I am looking to make this part so that it fits snugly in place between the spar and the leading edge. Once I have the perfect fit, I’m ready to make my repair pieces. I will label this template with the name of the plane, just in case I need to use it again.

5 CUTTING THE PARTS

Now I can use this template to cut out my three ribs. Use a sharp hobby blade and keep the knife vertical to make a straight edge with a clean cut on the ribs.

6 SANDING

Don’t put away that sanding block just yet. Use it to fine-tune the part for an exact fit. I like to sand all the parts together; this way I can make sure I have the same size ribs going across the wing.

7 PARTS INSTALLED

All three ribs are now glued in place and ready for covering. I used CA glue to place them so I don’t have to wait to move on to the next step. The stubs for the broken ribs are used as a glue surface to give the new ribs more “bite.” If you use epoxy or resin glue, just give it time to dry before adding the covering.

8 CUTTING THE COVERING

Cut the covering to extend beyond the undamaged rib; now you can tack it all around the damaged area. Finding covering that matches the base can sometimes be impossible and you have two choices. You can either use the covering that is close and live with the slight deference in color cast or choose another color with a design in it and duplicate it on the other side of the plane. I am fine with my repair piece being a slightly different hue.

9 APPLYING THE COVERING

Tack down the covering to all the solid wood around the damaged area and then use the heat gun to shrink it down. If you can’t find the same brand of covering that was used on the aircraft, make sure that your patch piece is of a material that uses a lower heat setting. This way, you will not melt the original covering.

10 FINISHED REPAIR

Here’s my finished, repaired wing all ready for its next flight. Total time for the repair: just a little over an hour. That’s less time then it would take for me to assemble another plane and a heck of a lot less money pulled from my wallet.

You can apply these steps to any damaged area and save that crashed aircraft. Remember: the money you save by repairing that crash can be used to get that great high-end radio you’ve been drooling over. That’s worth an hour of your time, isn’t it? Enjoy!

TEXT BY JOHN REID; PHOTOS BY HOPE MCCALL

How-tos, Uncategorized

About the author

Executive editor About me: I’m a publishing professional who has a passion for aviation and RC, and I love creating issues, books and a website that help RC pilots to enjoy this sport even more. I admire scale aircraft and enjoy the convenience of flying smaller electrics.

13 Responses to “Don’t trash that crash!”

  1. FHH says:

    Those of us that have built from kits have been doing major repairs for a very long time.

    I had a Sig Kobra (.25 glow, 1970′s design) which by the time I quit rebuilding the only original wood in the plane was the wingtips.

    I have known several trash can scavengers who got all of their aircraft by rebuilding what others had tossed. Sometimes the repairs needed were minor…

    Anything can be repaired. The question is: When is it easier and cheaper to replace it.

  2. C Jewell says:

    One of the best pieces of advice I received long ago was whenever you build a kit keep all the die cut blanks for any possible crash. All you need to do it just trace out the piece on a new sheet and cut/sand/fit. Saved me many times.

  3. Paul Mayhan says:

    I’m a committed dumpster shopper and am a bit amazed at the things that guys will throw away instead of fixing. I guess a lot of it has to do with how much they enjoyed the plane to begin with. Maybe the ones that crash aren’t their favorites?

  4. Chuck says:

    I wish they were all that easy to repair. I’m currently flying a Funtana 40 that had a heavily damaged fuselage. A lot of work, but I enjoyed the challenge.

  5. Bill says:

    Have never been one to trash the crash. If the crash is beyond repair have found that some of the crash trash can be used for other projects.

  6. Lanis B Ossman says:

    If all else fails, can you say “spare parts” :-)

  7. Jim Laurienti says:

    We have a designated airplane resurrectionist in our club. He is good at it, and actually enjoys working with epoxy, balsa scraps andcowls made from plastic bottles. To each hs own. In return for his labors he gets a resurrected airframe from me.

    As for me, there is a point at which I will eschew gluing and regluing and get a new airframe. The illustration shows a repair that any modeler should do in a drunken stupor, else he should take up macrame pot hangers. But destroy a fuselage such that everything north of a banged-up wing is thin air, and “Lazarus” gets first grab right before the dumpster.

  8. Jim says:

    I flew for years with our version of the “designated resurrectionist” whose nickname is the “Undertaker”. He could work wonders with what was left from a crash. He is the one who taught me to pack a plastic trash bag in the front of the tail section. The bag doesn’t change the CG but it sure helps keep all the bits from getting lost.

  9. Allen D. Hoffmann says:

    Most R/C fliers today have no idea how to build an airplane or tune an engine. I know owned a hobby shop. R/C flier by an engine trow out the instruction mount it on the plane and never touch the needle valve. They could care less about their engine, by cheapest fuel they can find and never use after run. So they conclude that glow engine are unreliable. Myself and friends used to raid their trash and rebuild their airplanes. Yes I’m a control line racer we build our planes paint them too and we don’t hover them like helicopters, further I tune my engines, including changing head shims and my engine run reliably and start first flip.

    • Roderick Warren says:

      Mr. Hoffmann, High sir, You said in your that you tune your engine. Can you tell me where and how I can get info for these doings. I have had people trim my plane and adjust my emgine. But when I ask how did they adjust the engin they say they tune it by ear. Well I am 77 and hard of hearing. I ask you again Where can I get info to do this correctly. Roderick Warren

      • Terry Solesbee says:

        You don’t have to hear it to tune it. You need a tachometer to do it. In a nut shell, start your motor and go to full power and use the tachometer to see how fast it is spinning / running.It will be on one or the other side of lean (needle in too much) or rich (needle out too much).If you see some smoke from the exhaust that’s a good sign,that means that it is on the rich side and that is better than being on the lean side for starters. After you check the engine speed turn the needle valve one way or the other 1/4 turn and check the speed again. Did it speed up or slow down ? If it sped up then turn the needle valve in the same direction another 1/4 turn. If it slowed down or quit then turn it back 1/2 turn the other direction and check the speed again.Your looking for the highest engine speed (RPM) and once you find that you will want to turn the needle valve out (counter clockwise) which will make it tun on the rich side slowing the engine down about 200 rpm from max. That is the best tuning for a glow engine. In flight you always want to see a little trail of light smoke behind it. it is always better for your motors life to be a little rich than a little lean.

  10. Terry Adair says:

    Now days it is not the cost of the wood so much as the cost of the monocoat that is a consideration for rebuilding. Here in Houston, Monocoat cost 20 bucks a roll and a major rebuild could require as much as 2 to 3 rolls + wood, glue, and other essentials.

  11. jim waddell says:

    my instructor, who was very good, i soloed my first day with a goldberg eagle 63 / enya 60, was an accomplished dumpster diver. however, i never saw a “goog” looking plane he had rebuilt. i think he covered with random pieces of film covering from other mishaps. he also used balsa salvaged from wwII life rafts. he rebuilt engines. they were mostly the old k&b 40;s. he even made pistons and rings for them. he even made his own fuel. he worked for som chemical outfit. when ever he fired up his engines, the old timers at the field, would head up wind from him. being new to the hobby, i asked them why. it seems that he was using nitro benzeen instead of nitro methane in his fuel. benzeen is a carcenogen (spelling?) and no one wanted to breathe the smoke. and you know those old k&b’s smoked….by repairing, i made my old goldberg clipped wing cub last about 20 years…

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