packet

I thought I would share my perspective on RC crashes and what causes most of them. I know Im preaching to the choir for most of you, but maybe our RC newcomers can benifit from my observations. Of all the planes I have crashed, 100 percent of them were due to pilot error, whether that be piloting skill or engineering. Of course radio failures happen, but given the reliability of todays systems, not very often. In my experience, 98 percent of my crashes were caused by engineering mistakes. Remember Murphy's law, if anything can go wrong, it will go wrong, and usually at the most inconvenient time. My last engineering disaster happened with a 1/5 scale Piper Supercub. I had to add quite a bit of lead to the firewall to ballance. I was getting concerned with the overall weight of the plane and thought I came up with a good fix. The prop shaft is a considerable distance from the firewall, therefore, less weight farther forward will do, right? I found a nice weighted propnut and that fixed the ballance. It was now perfect, and the first flight proved it. Things got real interesting on the second flight. About two min. into the flight, the engine threw the prop and nut thus changing the ballance. I picked up the pieces and went home to lick my wounds. I lost an aircraft that I had spent many months creating. I now have a second and third party look over my planes and listen to their input. I cant bear the thought of losing another plane or possibly hurting someone because of faulty engineering. A full scale pilot does everything he can to prevent a disaster, after all, his life is on the line. RC pilots should treat their aircraft the same way.

divergoff

I could not agree more. This really applies to people who fly real airplanes and decide to try R/C. I was one of those and destried a nice plane b/c I thought it would be easy. People need to start simple a build up, in both planes and maneuvers

mjfrederick

Nice points there, packet. I agree 100%. I know that all but one of my crashes (I've only crashed 3 planes, 2 of which were destroyed, not a bad record considering I've been flying for about 16 years) could have been prevented just by performing some sort of pre-flight check. Check the battery, check control surface direction and linkages, etc. Granted the pre-flight before a maiden flight should be much more detailed, but on a proven airframe a quick 3 min check of the plane before flying can save hours upon hours of building or repair time, not to mention money for lost/broken parts. I feel this is a subject not touched upon often enough on its own and ends up getting buried deep inside other posts. Thanks for bringing this up, and reminding us that we need to learn from our mistakes.

Flak

My Feedback: (1)

Packet,
The prop nut was part of your nose weight, right? Obviously, you did not tighten the prop nut properly. I always use a box end wrench to tighten prop nuts. This insures plenty of torque is applied. I have seen some folks use one of those 4 way glow plug wrenches to tighten a prop nut...Don't do it! You can't get any torque ot if that process. Good luck in the future.

RhyanO

Packet,
I also agree with your assessment that most crashes are PILOT ERROR either with the actual control of the aircraft or as a result from improper preparation.
You hear many blame radio interference, wind gust, an engine kills... the list goes on and on.

Happy flying,
Ryan

Villa

Hi FLAK. You are right on. I use a 10 inch adjustable because I have it available. This is way too large so I do NOT recommend it to others. The little cross wrenches we all have been using cannot tighten it hard enough.

packet

Flak, I did tighten the prop nut jast as you do, but somehow it spun off. Having seen engines that had properly tightened prop nuts do this, I should have known better.

k3 valley flyer

My Feedback: (18)

I agree totally, 99.99 % are result of some type of human error. Now over in the radio forum the guys who have jumped on the Spektrum band wagon want to convince us of the evils of 72mz radios. I don't buy it. Some say that at their field frequency conflict shoot downs are "a way of life". We have not had a shoot down in decades. I would suggest that if they have that many shoot downs they in effect don't have any frequency control system or at least don't have an effective one. If someone shoots you down at our field they owe you a plane, period. Also, if those fields ever have someone end up in court over a liability issue for injury, and it comes out shoot downs are common at their field, watch AMA deny coverage, violation of safety requirements, etc. So yes, good to hear someone admit most of the crashes are our own fault.

packet

Evils of 72mh huh! I dont buy it either. I have flown 72mh systems on at least a dozen different channels and never had a problem. These people have probably never flown 27mh systems like I did in the early days. We did indeed have more interference on that band but still, the crashes due to interference were very low. Like I said in an earlier post, I have never crashed due to radio interference or failure, but maybe Im an exception.

Sir_Sparksalot

My Feedback: (8)

Hello All,
I had a question for thought. I fly on a JR 72mhz Ch 26. I have not had a shoot down. More and more though, I worry about the home hobbyist that buys a plane and radio, either new or used, and flies it in his/her backyard or at a nearby field. Not knowing or understanding the AMA rules and regs of Channel Security/Safety. Has there been any talk on this that you know of, or am I just a bit over concerned.
Thanks for the thoughts on the safety. None of us can be reminded too many times. I personally met a man that was hit by a plane and is thankfully alive and recovering, though not the same as before.
One question for Packet. Was the weighted prop nut thrown from a two stroke or a four stroke? Would a double nut have helped the situation? Please let me know what you think I fly a few birds with with weighted prop nuts and don't want to have the outcome you experienced. Sorry for the loos.
Thanks for the great Thread!!
Eric

packet

Sir_Sparksalot, the engine was an OS .61fs, two stroke. I suppose that doubling locknuts would be better, but this could still fail. If you think about it, which I didnt at the time, any ballancing weight should be part of the airframe,and unable to move. Even worse than weighted propnuts, those adhesive backed lead weights are a ticking time bomb. With all that oil that ends up on the firewall, and the vibration, why would anyone want to stick a weight there?

DocYates

My Feedback: (102)

So all of these years after I witnessed a crash and heard "radio glitch" they could have been mistaken....surely not....(Satire dripping from my fangs)....

packet

Yeh Doc, more likely a glitch of the brain causing a glitch of the thumbs.

crash080

My "thumbs" have been responsible for returning many models to their kit form. A few others have been rekitted because I did not perform a pre-flight and lost a key connection (e.g. elevator linkage). In the 27 years that I have been flying I've had one "shot down" when someone did not impound their transmitter and turned on a transmitter on the same frequency. He was later expelled from the club because, although he admitted doing it "to see what would happen", he refused to replace the plane. Generally it was not a good situation. Anyway, I agree that the vast majority are caused by "pilot error" either while flying or by missing something before putting the plane in the air. All too often people simply pass it off as just a toy until they are reminded that it's like having a chainsaw flying around at 100 mph.

Flyboy76

My Feedback: (14)

I have had 3 crashes and 2 of them are not from pilot error. Still my fault but not my piloting skills. First one was a seagull p-51 crash where the servo control horn for the elevator broke off turning the plane into a lawn dart. It was my building error as i had trimmed off the other arms on the horn and got to close to this horn not leaving enough for strength. Second crash was my trainer Arrow from hangar-9 i was flying in a stiff wind and had adjusted my throws up to the max. i did a real sharp turn and the wing twisted in the saddle and 3 of the 4 rubber bands slid and jammed the aileron in the up position. I almost got it all the way down, i would call this more of a rough landing a very rough landing. third one was all my piloting bad, i tried to lift off to soon with my world models super chip with full flaps and snap rolled it into the dirt. So while they were all def. my fault it wasn't my piloting skills that caused most of my crashes. Looking forward to flying again once the snow stops.

Flyboy76

DocYates

My Feedback: (102)

Flyboy,
your signature is too funny, I never thought of a whiskey sour from lemons, but it makes more sense than lemonade....

hughesracer

Crashes are bound to happen, over confident stunts will do it too. One that wasn't my fault was the best I've ever seen. A Spitfire 40 ARF, I purchased at an auction for 50 bucks. The plane flew great for months with a 75 Supertiger, bomb drops, low attack runs. Then one day after a G turn, low full speed pass and a victory roll, the right wing came off. Watching it from behind it spun, up then arched into a corn field. It looked like a gun camera shot from WWII without the smoke. Buried the engine 8" into the ground. I wasn't upset because the show it gave us all was so good.

mundo330

My Feedback: (3)

I have rekited a few planes and helicopters in my 28 years of flying R/C. I can not attribute one to a "radio glitch". I have had a switch destroy itself (poor choice of mounting location) and a battery pack become disconnected (now I tape all my connections together). One of my most spectacular crashes was a Bud Nosen Trainer with a 108 ASP. 102 inches of wing and after a move to Florida must have been damaged in the move. The 21'st Century fabric hid the damage well. A spare let go and the right wing folded on the fist flight at Markum Park. I should have inspected it closer! And in '91 I had a 1/4 scale laser 200 with a Saito 180 twin and flying inverted just a few feat off the ground I forgot I was inverted when i went to pull up. REKIT!!! The only time I ever had a glitch was an electric helicopter caused by the speed control, poor choice of mounting location! The only time I ever saw radio glitches was on channel 20 at a field with a large communications antenna close by. The Channel 20 pin was left off the frequency board and a sign read " Due to interference Do not use channel 20 at this field". Well of course you will have someone not heed the warning.

Deadeye

I have crashed 4 planes in my nearly 5 years in this hobby. 3 of them were in my first year, and I attribute their demise to my inexperience. My last crash happened last spring with a SSE. 80 flights with a Saito 82 was too much for the RX crystal. It failed about 10 seconds into the flight, giving me no radio response. The SSE I have now has a vibration isolation mount.

aerowoof

I had two crashes over 30 years ago due to radio failure specifically one rx battery going dead the second was the tx pack went dead open cell.I must admit that I thought I had a glitch while flyng a model tech thunderbird about 20 years ago when I applied full up elevater to perform a manuver the plane nosed up as it should then snapped rolled and ended up inverted sort of a very sloppy imellman.I was low and far away at the tme so thought it was a glitch but after landing and checking everthing ,all was okay but i could repeat the scnario at will by just pulling full up at any time.I had too much elevator throw and was causing a high speed stall.since this was a new plane at the time if it had met it's demise I would have sworn it was interference but further flight test showed it was just too much control throw.reducing the throw from 1/2" to 3/8" solved the problem.makes you wonder how many other so called glitches could have been high speed stall from too much control throw.