How To Prevent a Crash
I‘ve seen many crashes in the four years that I have been flying model helicopters and most of them are pilot error, sometimes it is a glitch, a dead battery, or someone forgot to re-fuel their heli. If you want help preventing crashes and tips on how to keep your heli in good working order I invite you to read on.
One thing that I have learned over the years is to keep servo or gyro extensions short because they can cause glitches, especially on metal machines. If the extension gets too long it will act like an antenna. When you move the cyclic, collective or tail rotor a signal is sent to the receiver to move the servo a certain way but the long extension is also picking up a signal, so eventually the two signals meet and cause glitches. I have never seen this happen in flight but I have on bench checks. Another way to stop a crash is to keep any wires away from any spinning parts such as the main gear, up around by the rotor head, clutch bell or anything in that regard, if they come loose they may get caught and rip your servo and/or gyro wires or whatever you have hanging there leaving you with little or no control over the machine. You also don’t want to keep your antenna or any loose wires near is the muffler or jammed between any screws because the screws can chafe against the wire causing them to wear down. Eventually when it gets past the plastic/rubber insolation it will rub up on the metal causing glitches. You shouldn’t have to worry about stuff like that if you are a neat and tidy kind of person. My dad and I like to bundle up our loose wires in velcro strips so they can never make contact with anything they shouldn’t. We always try to have our antenna on the opposite side of the muffler connecting it to the vertical tail fin with a rubber-band so it cant rub against the hot metal and short out the wires. In some cases this may be ok if the muffler and antenna have a good spacing apart.
You should never ever leave any screws loose in the side frames as they can rattle around making little sparks that the eye can’t see, this is a good start to getting glitches. This is why you can never be too lazy and must double check everything over at the beginning of a day out at the field. I’m not saying to bring your manual out to the field and go over the whole heli step by step, just the most obvious parts which you think something could go wrong with.
Crashes normally happen out of stupidity and no one is to blame but the pilot, well most of the time anyway, sometimes there may be an unexpected mechanical failure. I’ll tell you about one of the crash experiences I’ve had, and it was due to a servo failure. It happened about three years ago when my dad was flying his X-Cell gas machine. He was fairly high up flying around inverted and suddenly it went into a nose dive rolling straight for the ground, of course we all thought he was doing something just to impress us. Oh and it did, because he had pulled out at the last second but as he was flying low and slow across the field it rolled inverted and drove it self in the muck. I thought he just messed up but during that moment he had no control over the roll servo. It didn’t come unplugged or anything of that nature, it just stopped working, from his control point of view the servo was doing whatever it wanted. But that was not my dads fault, there was no one to blame other then the manufacturing process.
Sometimes in haste people forget to check for binding in the control system at full travel and throw a linkage. The results are expensive and embarassing. It can happen to anyone just as easily as selecting the wrong model in the transmitter might happen.
Last but not least one of the main ways to stop a crash from happening is before you try anything like a complicated trick always be sure your pitch and throttle curves are properly set up. If not, you may possibly have a flame out, reduced engine power and rotor speed, or not have enough negative or positive pitch. Generally, make sure your heli is in good shape. If you think some thing seems wrong or looks out of place then you should always double check, never leave it, and if you don’t understand how to fix it ask for some assistance from someone more experienced. If you’re not totally ready to do a trick and you just want to impress your friends don’t take the chances because the odds are against you and the only thing you’ll be impressing them with is the most spectacular crash of the year. To your benefit, invest in a battery voltage checker if you do not already have one. This will allow you to check if your rx battery is ok for more flying at about the space between every 4-5 flights depending how large you battery is. Remember you should always follow through with a daily inspection because the feeling of a crash in not pleasant, trust me! I have never had a crash from pilot error or because something along the line of a loose part or even a battery failure. I have only had two prangs, the first being a mid air and the second from pushing the model beyond its abilities causing an inflight boom strike at the bottom of an inverted exit “death spiral”. Many helicopters have aerobatic limits that need to be respected or you may find these limitations the hard way. Remember this hobby is much better if you stay safe. Not only do you do this for yourself and your machine but also to keep members and spectators safe so we can all enjoy the hobby.