I am pretty sure the threat of unpleasant consequences does not work for everyone, but for those of us for whom it has an impact -- in case the awful result isn't enough, consider this -- you would almost certainly face both a manslaughter charge as well as a civil lawsuit if this incident occurred in the U.S. Don't even bother to start with the "that's why lawyers suck" nonsense, because bottom line is that our laws exist to protect us from people who demonstrate a "reckless indifference" to the lives of others. Is it reckless indifference if you fail to set your PCM failsafe to engine cut? I don't know, but I sure wouldn't want a jury to decide for me.

No one is trying to be a killjoy on anyone else's fun. We just want to make sure no one gets hurt as a result of that fun.

Antony

Boy this makes me think..
Back in the early nineties I had a G62 stinger combo fly away with a PCM radio. Throttle was set to go to low, but not low enough. No damage done except for a totaled stinger but it was a bad situation and I swore to my self that I would never fly again without a secondary kill system. A channel dedicated to a micro switch was adequate back then, but certainly not the best solution. As I have moved entirely into electronic ignition I cant say enough for this guy:

http://www.smart-fly.com/Products/Ignition/ignition.htm

$60 buck and thirty minutes of your time buys a LOT of peace of mind.
For you guys relying entirely on fail safe for your big block, I implore you to think again and spend the dough on this or anything similar.
A couple of milliseconds is all it takes to change peoples lives.

Thanks Jet guys for letting this thread continue here !

After reading this, I have been moved to add another layer of safety to my blossoming turbine career. Just as I have a spare pair of hearing guards, I will go straight to wal-mart and buy an air powered blow horn to hand to my spotter along with the hearing protection......

After being dumbfounded at watching my turbine fall into the ground (engine was shut off when model was deemed uncontrollable) I was soooooo relieved that no one got hurt. I learned many lessons that day and today I have learned a few more. I will set all my prop airplanes to engine off with failsafe.

Just for thought, what if, we could make a speed and altitude limited parachute deployment upon failsafe? A speed sensor can be bought from jetcat. A gps that senses altitude is also available. Yes, these are expensive (cheaper technology is out there, just look at some of those awsome casio watches...) but, I would pay $400 to save anyones life! Even those people on RCU that just love to start fights!!!

With some luck, the parachute would slow the model down giving it a more predictable trajectory and if just tore the airplane in pieces, then maybe the resulting increase in cross section, would slow the pieces down.....But again, if this were to happen among a group of spectators, then this would transform one falling piece into many falling pieces, albiet smaller pieces with less mass!!

I wish I had the capitol, ingenuity and the time to design something like this. From what I've been able to gather, when these turbines go into failsafe, there is not much we can do to save them anyways.....

I suppose a solution would be to set failsafe to snap with a parachute deployment....The snap would slow the airplane down and the parachute would give it a predictable trajectory....

Hey, I think I'm on to something!!!

sorry, I'm just rambling...

But, truthfully, every flying day should be a day in which we can scrutinize, atleast, our own behavior into a safer one. Safe and happy flying to all.

Raf

On what basis do you make such a claim ?

To me, the model seems to have went out of control approximately 5 seconds before impact. That's not enough time to bleed off enough kinetic energy to make it non-lethal, even with the engine at idle. However that's no excuse for anyone to not have a PCM failsafe go to idle.

To me, the main reason for PCM failsafe is to prevent energy buildup when uncontrolable model flying at high altitude gets into a nose down attitude with WOT. It's not a cure-all.

P.

P.S.
Did anybody notice the ING commercial shown just prior to the accident report with kids peacufully flying model gliders ???

ING commercial? What video link were you looking at? Please post.

It was posted on the first page of the thread:

mms://stream.publishing.hu:1755/tv2/video/tenyek/tenyek_0513_low.wmv

5 seconds is more than enough time to stop a prop by having failsafe set to engine kill

I switched back to PPM 10 years ago and I am much happier with it... I did crash a jet
with the PPM in Deland but I had some control all the way to the ground.

I get a lot more bumps and hits than everyone else but I see them all and when I get
two in a flight I land... no big deal...

I can't say if PPM (FM) would have helped in this case, but if it was like my crash he would
have %50 control at first.... Then %20... more than enough time to chop the power and
have the engine power back.. Way better than lock out at full power...

Eddie Weeks

I thought I was the last person on the planet to not belive in PCM. I fly PPM, and don't plan to change. I will gladly change to spread spectrum pretty soon, when that gets refined. But if I did fly PCM, the failsafe would be set to kill the engine! Anything else is nuts.

The funny thing is, when I range check my plane, with the engine running (PPM) I walk
until things start to chatter, and the engine quits right away sometimes... as the receiver gets
bad frames, it only takes one frame where the engine run channel goes to the stop engine... and
the engine quits... Also.. If I turn the transmitter off... The turbines quits right away.. A sec or less...
If the AMT ECU quits getting frames it shuts down really fast... The IPD system with multiplex is very
similar. Something to think about... I don't think if anyone will change back to PPM because it requires
less expensive radio gear...
Eddie Weeks

lol ...

From my experience (failed throttle servo, killing the engine using electronic kill switch in order to land), it takes around 15 seconds for a 32x10 CF prop to actually come to a stop during level flight.

20kg model at 80 mph (33 m/s) has 10890 J kinetic energy. Your average, relatively high-drag, giant scale model will slow down to approx. 55mph (23m/s) in 5 seconds, dropping the energy down to 5290 J.

A 32" prop has has moment of intertia approx. 0.025 kg/m^2, so spinning it at 5000 RPM gives you 3152 J kinetic energy.

A 9mm bullet right at the nozzle has approx. 500 J kinetic energy.

Either scenario is a losing proposition.

Although not intuitive, you're better off falling into a stationary 32" prop at 5000 RPMs rather than getting hit by 20kg glider at 55mph. Your worst nighmare (like the accident in question) is a spinning prop on a nose of a heavy airplane

P.

15 seconds!? That's a loong time. My 26" prop stops in about 5 seconds.
Sounds like you need a set of rings

It is said that “Charity beings at home� and such how many of you that have attended a jet event this year
had your AMA engine kill checked by the club or event organizer?

We should make it a must at every major / non-major jet event with no exceptions.

Sounds like something's wrong with your engine.

I'll tell you what.... if I give you the choice of sticking your arm into a 34 inch prop running at full bore, and doing the same for a prop that's windmilling lightly 5 seconds after being shut down on an engine that apparently has little or no compression - which would you choose ?

Given that you assert point blank that PCM set for engine kill could not have made any difference to the outcome of this event, either you have documented proof that the fatalities were not in any way attributable to the prop, or you believe that being struck by such a prop at full power can't kill you -- which is it ?

Gordon

What I'm saying is that, both the plane with windmilling prop and the fast spinning prop on its own, have enough energy to kill you several times over. Just shutting the engine does not make the plane safe - just a bit safer. From the video, I'm not able to tell if the engine was set with PCM idle failsafe or not, but even with the engine shut, there wasn't enough time for the plane to slow down to a non-deadly airspeed. I doubt that both victims got a direct prop hit, suggesting to me it was purely the total mass/velocity of the thing that did major part of the damage.

The major advantage of killing/idling the engine with failsafe is that hopefully, in most scenarios, the plane will impact at lower speed than with an engine running. However the plane has enough energy to be deadly several times over even with the engine dead.

Another wakeup call for me is what seems to be a generally accepted "safe flying practices" by the pilot - flying parallel to the runway behind a seemingly reasonable deadline, yet it's no help and doesn't give anybody time to react. I doubt sounding a horn would have helped much here either.

A really tall fence separating the spectators from the flying activity is about the only preventive measure I can see helping here.

I don't have the answers, but increasing the overall reliabality of the control system we all use sure sounds like a good start.

P.

Jussi,
AMA Experimental Class aircraft for many many years...until just recently were required to have a full fail-safe system which would kill the engine and deflect all flight surfaces to the max... to effect a snap roll engine out... so the aircraft would not be able to wander into a crowd. Rather it would basically stop flying and screw itself in ASAP!

As I have said before I believe this should be a requirement for all model aircraft weighting over 20 lbs. I have been flying my turbine powered Jets with this fail-safe setup for several years.

While a member of the Denver Airshow Team throughout the 90's and flying at many full scale airshows we always had fail-safes set for full snap-roll deflection... as I recall we had one or two radio failures over a ten year period of time and in each case the airplane just screwed itself in out in a safe flight zone.

If you've ever been at the controls of an model airplane that has locked up, with only the factory default HOLD fail-safe settings, you'll understand why this should be a requirement.

In court when the prosecutor asks you... did you do all you could to avoid an accident? What would your answer be?
Lee H. DeMary
AMA 36099

OK, here is the deal. It was a Composite-ARF Pitts S-10, with a 3W engine. The pilot is a highly qualified German pilot, of the caliber of the pilot who put the 117 in a few weeks ago in California. I have his name and have seen videos of him flying at different shows. He is a superb pilot but posting his name here would serve no purpose. It appears that a local pop radio station was broadcasting on the same frequency that he was flying on that lead to the interference and crash.

The two deaths were an elderly couple, husband and wife. Both died instantly and it was gruesome.


What a tragedy for everyone.

I saw the same aircaft type demonstrated at the WJM in Hungary last year (same size/sound/colour). If my memory is correct - it was flown by a German guy - and it was huge! If it's the same guy - I thought he really flies very well - shows what can happen when a problem strikes.
Great tragedy for all.

Leon

A normal parachute will open in 3 seconds. A ballistic deployed chute will open in one second. More then enough time to have prevented this tragedy. This kind of chute is used on ultralite planes they should be mandatory on large RC planes.

Sounding a horn would only have people looking in the direction of the horn. It doesn't appear as though the pilot of this airplane did anything willfully reckless or problematic.. except not setting the failsafe to idle/kill on the engine, which would have at the very least reduced the energy of the crash by a great deal.

Sadly, I have flown at many airshows where people are allowed to fly who have much worse problems than this, only they've been lucky whereas this pilot wasn't. One pilot is repeatedly asked to fly at airshows, even though I've seen him routinely behind the safety deadline, and at least twice, was so far behind himself that he was actually over the assembled crowd and over the static display area. I have also heard of someone crashing a turbine so far behind the crowd line that it actually came down next to a hotdog vendor.

Just because you're able to takeoff and land at your local field does NOT mean you're capable or qualified to fly in airshows. We seriously need to do something in this country to get this under control in my opinion, or we're just another accident waiting to happen.

That´s exactly the problem...this seems to defy logic. I am flying now my turbine weekend beater on PPM by a personal preference and not because it is less expensive. The main reason that I am doing this is because the PPM plane warns you that something wrong is building up inside the plane, or in the frequency itself ... and as long the turbine shuts down by the ECU if the data frame is bad enough, It already have the main advantage of the failsafe feature present on PCM receivers.

And as far as i tried it (about 80 flights on PPM, in a very busy club) it seems to work very well.
meanwhile other PCM airplanes (not jets) crashed by undetermined causes... so I am quite in the
dark here, using what seems to work best.


Enrique

The news report said he was an engine and airframe manufacturer...and it says 3W on the tail, you don't see engine manufacturers flying somebody else's brand in demos, and the news told where in Germany he lived, so it's not really a big mystery to most to figure out who he is. Does not really matter, though.
As far as the "local pop station" being the culprit, I seriously, seriously doubt that. It was rather sudden interference(if it WAS interference) I don't know of too many radio stations that suddenly switch on during the middle of the day. While it is possible, it's rather doubtful, I think it would be better to wait for more facts to come in before accepting such a conclusion.

I thought he meant that they were doing a live broadcast from the event.