Avoiding Crashes — 5 tips to save your RC airplane!

Avoiding Crashes — 5 tips to save your RC airplane!

Avoiding Crashes — 5 tips to save your RC airplane!

We’ve all been here, done that!

The life expectancy of your RC airplane is directly proportional to how well you follow directions. That is to say, you’ve built and setup your plane properly as explained by the instructions. This article is intended to give the first time model builders some helpful tips for being successful the first time out. We’ll talk about avoiding the avoidable, not correcting for things like crosswinds or hitting something with your plane.

There are several things that are common in that they can greatly affect your airplane’s safety. Like a weak link in a length of chain, any one of these things can bring the best built planes down. Let’s break down these areas of concern into the following groups.

  • Center of Gravity Balance Point. In my opinion, more airplanes are damaged or destroyed on their first flight because they were improperly balanced. The balance point for all RC model airplanes (with the exception of small foamy RTF planes,) are called out on the plans of a kit built plane, or in the instructions of an ARF plane. It is absolutely imperative that you take the time to balance your plane properly. Use a balancing jig or simply use your finger tips to hold the plane by the wing to see where it balances. If the tail hangs low while placing your fingers where the instructions say the balance point is, it is tail heavy. If the nose hangs low, it is nose heavy. Of the two, slightly nose heavy is better than slightly tail heavy. As the plane becomes more and more tail heavy, the more and more sensitive it becomes to control inputs until it gets to a point where it is uncontrollable. We’ see this all the time. The plane takes off and the wing rock back and forth. The nose stays high and eventually the plane snaps to one side and crashes. You prevent this by adding nose weight.

Avoiding Crashes — 5 tips to save your RC airplane!   Avoiding Crashes — 5 tips to save your RC airplane!

(Above) The GP Balancer is a great tool to have in your workshop. Du-Bro Stick on weights are excellent for adding nose weight.

  • Engine/Fuel System. The next item most likely to kill your plane is an unreliable engine. This can be caused by a poorly broken in engine, an improperly adjusted carburetor and/or an improperly installed fuel tank. Always follow directions and break in your new 2-stroke or 4-stroke engine before trying to fly. This requires several tanks of fuel and a controlled running of the engine to condition it for proper operation. What you want to do is obtain a reliable idle and a smooth transition from idle to full power. When it comes to power output, always run the engine slightly rich, not lean. Lean engine runs cause overheating and can lead to a damaged engine. The fuel tank should also be installed properly to supply the engine with fuel. Assemble it correctly and install it so the center of the fuel tank is even or slightly below the center of the carburetor. The simplest setup is a 2-line setup with the output line attached to the carburetor and the other line acting as a vent. You fuel the tank by removing the line from the carburetor. A common problem is a fuel clunk that gets jammed forward in the fuel tank after a hard landing or nose over. Always make sure the fuel pickup line is free to move around in the tank. If it is jammed forward, the next time you take off and the model’s nose is pointed up, the fuel level will move back and the clunk will start to suck air and cause your engine to lean out and die. Avoiding Crashes — 5 tips to save your RC airplane!

(Above) The model airplane engine is an important investment in your hobby. Treat it right and it will treat you and your airplane right.

  • Radio Battery. Another common failure point is the onboard battery powering the receiver. You should always fully change your radio system the night before you go flying and have a battery checker to monitor the condition of your battery pack at the flying field. Batteries seldom fail before you next flight, and when they give up the ghost during a flight, you are out of luck because your model is going to lose control and it will eventually hit the ground…hard! I check the battery voltage before every flight with a loaded volt meter. You simply plug it into the charging jack and it tells you what the voltage levels are. If the voltage is below 4.8v for a 4 cell pack or below 6v for a 5 cell Ni-Cd pack, do not fly! So it is always good to have a DC quick charger/peak detection charger in your field box so you can top off your battery pack. Also, check the battery switch and connections. Never install a battery pack without foam rubber padding. Always make sure your pack is securely installed and doesn’t more around.

Avoiding Crashes — 5 tips to save your RC airplane!

(Above) Use good quality battery packs and use high capacity packs when you use more and more servos in a plane.

  • Final Condition Check Besides these three basic failure points, always check the condition of your model before every flight. Make sure the radio system and servos are properly installed and working correctly. If you have a programmable radio, make sure you have the correct model memory called up for your airplane. Check the screws and clevises and make sure everything is connected and secured properly. If you have recently repaired a plane, or if it is the very first time you’ve brought it to the field, have a friend go over it as well. A second pair of eyes can often detect something you over looked. Always check your control throws for proper amount and proper direction.
  • Don’t push a bad situation! Again, we see this all the time! If your engine is just not operating properly, or if something is not working correctly, just don’t fly! The best course of action is to step back and take a breath. Maybe you need to work on the engine back home on a plane stand, to solve the problem. If an aileron is twitching, maybe the servo needs to be replaced. You are the pilot in command. Abort your flight attempt. The plane you save may be your own!

Avoiding Crashes — 5 tips to save your RC airplane!

Photos courtesy of rcplanescrashes.com

Updated: July 23, 2015 — 10:30 AM

18 Comments

  1. These are all excellent points, and I hope to never be a victim of them. I my issue in every crash I had is stick freeze/disorientation. Inverted to close to the ground, moved the stick the wrong way…Near an obstacle flying towards me, moved the stick the wrong way….See a pattern 🙂

  2. Don’t push a bad situation got me. Had engine issues; Couldn’t get the mixture right and it kept dying when I cut the throttle. I flew anyway and was practicing stall turns. I was able to make a few then it happened; motor died. I was trying to glide back to me and got greedy because I didn’t want to walk in a cow pasture to go get my plane so I tried to make it all the way. She tip stalled at 60 feet and I almost recovered out of the dive. It was a glancing blow with terra firma and fortunately with a little ply, balsa and monocote; was repairable. I was one of the lucky ones… My plane flies again…

    When I was learning to fly my instructor said “Don’t fall in love with it. All planes have an expiration date on them; we just don’t know when it is…”

    1. all good advise. made me smile thinking of all my mistakes and planes over the years. A smart man told me, “They don’t always come down the way you want them to.”

  3. thanks for this tips, 30 years loving RC planes, but never learned to fly, now I decided to do that, Im building a Kadet Senior, adn collecting all tips to put it in the air, Im a little afraid!! but definetly has to do this step!!

    1. A good choice,get help when you fly.

  4. Hello, very good points. From my experience, no gas, and not checking the battery was some fatal causes at my field. I have a Patty Wagstaff Extra 300 that I fly in Arizona at Superstition Airpark, e maiden flight the wing flew off. Caused by vibration from the engine, it vibrated the nut right off. It is amazing how a little thing like a nut would bring a plane of that size down. ALWAYS CHECK THE AIRPLANE BEFORE EACH FLIGHT.

  5. I liked all your tips, here is one more that I think causes many crashes, it is flying past our attention span, which is about 10 minutes for me. I don’t have any statistics but I do believe that most dumb thumb crashes occur after 10 minutes of flight.

  6. On one of your comments of balancing I have is my plane is nose heavy could not move radio gear far enough back to balance so I added a little tail weight’ was this the correct way she seems to fly good but seems a little heavy now the model is great plane stick 40 arf with a os 70 4 stroke any thoughts what I could do different or leave it alone Thanks A lot of great stuff on this news letter Andy Michels

  7. I lost my pride and joy Venus2, now discontinued. The cause of the crash was a faulty receiver switch. I purchased this Hobbico “heavy duty switch” this spring. I intend to send that back with a nasty grahm… FYI make sure you have complete control while moving the wires around (that come out of the switch)

  8. So I crashed..sad but let’s get the craft put back together, done! Everything is fine with all the controls except the electric motor does not run. Check battery, all controls work (except motor) OK, check the transmitter, all is OK, I have selected the correct model, all switches are on…help!!! How do I find out what is wrong with my motor?

    1. Check your ESC…mine with UBEC has unsoldered resistor ground so when I start fliing and go for dive resistor lose contact with ground and cut my TX off and motor was running for 5 sec, lose signal stoped and chrashed… Thanks for trainers and my knowledge of electronics I have repared and he is alive

  9. I need some help I recently crashed my apprentice 15e and I don’t think I can save the body on the plane. I need someone to give me some tips on how to deal with the issue im prepared to build a new plane if i need to… all the electronics are fine and working my number Is (361)-396-9286

    1. Jack, Is this one of the foam Apprentices? In many cases, you can do some repairs with epoxy. Do you have a picture of the crashed plane that we can see? Wings are usually easier to fix than fuselages, but if we could see the extent of the damage, maybe we can help you. I’ve cracked up a couple of foamies, and unless it is severely damaged, it may be fixable. You may also have to add some reinforcements to the areas of the fuselage that have been busted. It has been my experience that when the fuselage breaks, it is usually in the tail area. But sometimes the nose area can get crushed in the impact is in the front. I had a foamie that I fixed using epoxy to glue the tail section together. You can also use some kind of reinforcement to add some more strength to that area. Make sure that if that repair is what needs to be done, that you check the center of gravity again and make any adjustments needed. My plane that I had to do that with was a HobbyZone Mini Super Cub. But if you need a new fuselage,They should be plentiful for that plane. How are the wings? No matter what, you will have to install your electronics into the new fuselage, and possibly the wing as well if you have to get a new one of those. I just hope you don’t have to get a whole new airplane. If you really want to save some money, check out some of the local RC plane swap meets. You may be able to find one there. Make sure you have someone who knows what they are doing with you so you can get some good advice. If you are in a club, someone may actually have one you can get. I’m just proposing some less expensive ways of doing this. One of the guys in my club actually got his wings flying an Apprentice.

  10. Good advice plus reread this, repeat and re read 😀

  11. Use the correct servos and servo arms! Lost my Revolver 70” due to using a weak Servo and mostly to my choice of Servo arm extensions (the one where you use the saddle and then the sliding arm)yeah the screw for the servo arm is only so long and the result is it vibrated lose on take off! My plane did snap roll and then SMASH! Into a million pieces of balsa! Also to add to this is Always add extra glue to your ARF they don’t put enough glue on at the factory. It can be gas/Nitro or EP it can still vibrate apart

  12. I have a Black Horse Stuka with a YY120 fitted. I am setting up the Flaps prior to its maiden flight. Do I need to mix in some elevator with ten flaps or does this model stay neutral when flaps are activated???

  13. Why do low wing planes need to be balanced inverted?
    The C of G cannot move by its self, it’s a fixed point on the airframe.
    The mass of the plane cannot change by its self, whether it’s inverted or right way up.
    So why do people say it is important to balance low wing planes inverted?

    Rinnie

  14. CG was mentioned front to rear, but no mention the leveling of the wings

    Next, it was mentioned if you lose your motor battery, a crash will result. Not true. You may lose motor power, but still have enough power for you to have a controlled landing.

    Best back would be to have 2 batteries, one for the motor, and the other for the electronics….

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