First-aid kit for crash repairs
- > Clear packing tape
- > Various glues: quick-drying CA (foam safe, if you fly foamies), epoxy
- > Glue gun
- > Fiberglass or cotton material for reinforcement
- > Balsa scraps and/or ice cream sticks
- > Covering material
- > Covering iron
- > X-acto knife
- > Needle-nose pliers
- > Soldering iron
- > Scissors
Clean sweep–don’t leave any part behind
The first thing to remember when you get to the crash site is to turn off the power. You may then want to mourn a bit before you begin the salvage operation; this is perfectly fine and accepted in the modeling community. When you’re ready to move on, gather up every piece of the plane you can find; this is a very important part of the repair process. Once back in the shop, begin to put the puzzle pieces back together, and if a piece is missing, I almost guarantee that it will be the hardest one to duplicate. So make sure you pick up all the pieces. Now let’s look at how to repair some common crash/bump damage.
Landing gear–the first thing to make contact
By far the most common airplane mishap has to do with the landing gear either getting pancaked or being pulled right off. After all, this is the first thing that touches the ground and is, therefore, most likely the first thing to be broken off. Many times, new and experienced pilots will stall out the plane on landing, and the plane will hit hard, thus putting a lot of pressure on the landing gear. This constant pounding eventually breaks the plywood that holds on the landing gear.
Reconstruction begins by removing the landing gear and piecing all the parts back together. Use thin CA to glue the parts. Reinforce the inside of the landing-gear platform with triangle balsa stock, and use fiberglass or denim material with epoxy to strengthen and bond all the pieces together.
On foam planes, use foam-safe CA or epoxy (although this will add some weight) to glue all the pieces back together. Reinforce all the parts with clear packing or reinforced tape.
Wingtips–damage at the ends
I have seen many competent pilots tip-stall a plane on landing and cause damage to the wingtips. This type of damage is common to many planes, especially low-wing designs. It’s best to prevent rip tears in the covering in the first place by adding a protective wingtip covering. A number of products on the market will prevent wingtip damage, including plastic wingtip guards and adhesive Mylar that sticks to the covering. Both products prevent damage by taking the brunt of the abrasive impact on the ground. But if you’re like me, too late for that; damage done. How do I fix it?
The first step is to remove any shreds of torn covering and fill in the damaged balsa or plywood wingtips. You can do this with any wood fillers, but I found spackle or Lite Spackle (available at home centers) the easiest to use. It is easy to apply with a putty knife or an old credit card, and it sands faster than balsa, creating a smooth finish. Cut a piece of color-matched covering that overlaps the existing covering by at least 1/2 to 1 inch all around the damaged area. Use an iron with a higher heat setting, so you can stretch and mold the covering around the complex curves of the wingtip. If you aren’t able to color-match the covering, use a color that works with the color scheme. Cover both tips so that it doesn’t look like a repair when you’ve finished. And once you’ve achieved a great-looking repair, why not try that scuff-resistant Mylar film this time?
Covering repair –easiest to damage
The second most common repair is fixing holes in film covering. This damage occurs when you poke your finger through the covering as you pick up the plane, or when a stick pokes through on landing, or broken parts break through the covering, or during transportation to the field. Any of these events can leave your pristine covering damaged and unsightly. These areas need to be repaired as soon as possible because the damage will affect the aerodynamic stability of the plane. The torn covering will get worse as the air pulls up more and more covering on each flight.
At the field, you can do a quick repair by using some good-quality packing tape to place over the ripped covering film. Cut the piece of tape so it extends at least 1 inch beyond or around the damaged area. Stick the tape to one side of the tear, and gently pull the tear together before you push down on the entire tape strip.
Once at home, you should make a permanent repair. The first step is to purchase the same color covering as in the damaged area. The covering brand and color are often printed at the beginning of the assembly manual. If the damaged area has a complex color pattern, or you just can’t find the right color of covering, you can still repair it by using clear covering.
Whether you use a matching color or a clear covering, the steps for repairing the damaged area are the same. Use the low-heat setting on the covering iron, tack down the repair covering on one side of the rip, working from the center out to prevent air bubbles from forming under the film. Pull the repair covering so that the gap in the damaged covering closes, and then tack down the covering again working from the center out. Now, turn up the heat on the iron, and go over the entire repair area to get a nice solid bond that should last the life of the plane.
Motor mount–the front is the first to hit
The new breed of outrunner motors has much more power and durability than motors from just a few years ago. These well-built powerhouses don’t bend or break when the plane encounters a prop strike. The force from the strike is instead transferred to the motor mount, which in many cases is much weaker than the motor. Even a light prop strike may result in some significant damage around the motor mount. Repairs in this area are easily fixable, in most cases.
On foam models, glue all of the pieces back together with foam-safe CA or epoxy. When using epoxy, try not to overuse it because cured epoxy adds a fair amount of weight. Fill in any gaps with foam-safe CA and microballoons, and then reinforce the area with some packing tape. Reinstall the motor, and you’re good to go.
For balsa models, the fix will require a little more time. Again, glue all the pieces back together with CA. Depending on the construction of the motor area, you can use extra 1/16-inch balsa sheets to reinforce the area, or use light fiberglass with epoxy or CA. I also found that Popsicle sticks work great to beef up an area, especially around the motor mount. Some planes have the motor mounted on a motor box; to reinforce these, you can use balsa triangle stock to strengthen the inside corners. When you’ve finished the repairs, sand everything smooth, and add new covering and/or a new cowl.
It’s all good
Now you should be able to fly at ease in the knowledge that if an accident with your plane does occur, you can rebuild and, in some cases, make it better than it was. As the saying goes, “If you’re not crashing, you’re not flying”; but now you also know that a crash doesn’t always mean the death of the plane. Enjoy.
Last but not to be forgotten, make sure to revisit balancing the model! Make sure the wing CG and centerline of the model are back where they belong or you’ll be back at the shop repairing faster than you can say, “Oh Fudge!!”
I have had a few lol crashes this year with my big gassers and ive found that going over the joints in the airframe with liquid steel epoxy before you have a crash helps keep damge to the airframe to a minimum and it also keeps the damage from normal vibration down too the liquid steel epoxy does not weigh much either it doesn’t look as pretty as thin ca but it works alot better thanks for listening to my 2 cents fly low
One thing I have learned after many crash repairs is to not forget to recheck the CG when repairs are finished. It often changes after the repairs are completed.
Often times, pilots throw the plane away in the anger, frustration, and disgust of the immediate post crash emotional moment. I have done it myself. Try this: MAKE yourself gather up every single piece of the plane, and put it away for a week or two out of sight. Then get it out and have a look at it in a calmer state of mind. You will find nearly always when doing this that instead of wanting to beat the thing silly with a hammer, you instead automatically start seeing your way to a repair. Works for me!
I have a small foamy cub that is mostly packing tape and glue and round toothpicks. Still flies good. Just doesn’t glide as good as it is on the heavy side now.
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