Jim,

One more point to consider every aspect of this hobby has it's own unique set of risks associated with it. For turbines it is the risk of fire. I think it would be really diffucult to classify fire as being any more risky than getting hit by a large gas powered prop plane with a 30+ inch prop, or getting hit by a helicopter with carbon fiber rotor blades, or getting hit in the chest by a trainer.

David,
I am NOT missing the point rather I am looking at a different point than the one you have in view. There is no question about statistics since the AMA cannot afford a single major fire caused by a model and turbines have already shown a much greater risk toward that than any other model due to the amount of flammable carried to the scene of the crash and the ready ignition source. This constant battering of the fire issue with non-turbine planes is a perfect example of your different approach to the problem. I don't know of anyone who ever said that gasoline or alcohol doesn't burn and yet you constantly throw up the great many fires you have seen in those types of power plants as an example of a bad thing for jets. I happen to feel that doing that is sort of like comparing apples to oranges. They may both be fruit, but that is where the similarity stops.

You and Mongo report things I have NEVER seen. In over 25 years I have NEVER seen a glow powered plane crash result in a fire, but I have seen one engine catch fire on the ground. In over 15 years of flying gas burners I have NEVER seen a crash that resulted in a fire. Yet you both report multiple burns of those types of engines. However, Mongo does admit that at least one fire was actually caused by another agent, namely an electrical short before anyone got to the crash site. I don't think that really counts as a gasoline fire, rather a fire that was accelerated by the gasoline present at the crash site. That is exactly the same thing as many have noted holds true for a turbine crash that results in a fire, but with MUCH less fuel available and much lower likelihood of ignition because of the fewer lower temperature parts around. As for Mongo's and your reports of fires with electric planes, I know for a fact that many of us are capable of letting the smoke out of those things. They don't even have to be flying to do that! So that is really no a big issue.

The issue about the turbine community being safe is not really germane as nobody has really questioned that. Rather they have questioned the ability and willingness of that community to enforce the rules they have already agreed to. Remember, turbines are ALREADY prohibited in the AMA Safety Code. That is why you need a waiver to fly them and the jet jocks already agreed to certain rules that are currently being broken. Mongo goes to bat for you guys saying that there should be no rules limiting you that are not applied to the entire community. That seems to suggest that Mongo really wants us to stop flying turbines in the AMA. Now THERE is a rule we can enforce!

JR suggests that the rules are put in place to attempt to control the behavior of the flyer who has less than his or her issue of "common sense". I think he is right, but I am not sure that any of the suggested, approved, or temporarily put aside rules is any where near stringent enough. As Augiep38 implies, the wealthy modeler can just buy another plane when his dies, without learning why it crashed. Those are the folks we need to find some way to guide to safe operations. Rather than tell me that no jet has ever killed, or that gas/glow birds are statistically just as dangerous, or any other smoke you choose, why don't YOU design a solution?

It sure looked to me and others like that was the approach taken by the TRC and you seem to have some grief with it. I strongly suggest that you need to do something better or accept what work others in your genre' have done in your behalf. Don't tell me about risks, tell me about what YOU would do to lower the risks inherent in turbines and turbine users since that type of propulsion system is currently banned within the Safety Code.

i would remove the turbine ban from the safety code.
i would add a line to the code limiting speed of any model aircraft to X mph, yall argue amoungst yerselves for the value of X.
that no plasma bag type fuel tank from the turbine rules now, would be added to the affects em all rules. (containment of fuel, whatever kind, is the most important step in preventing crash fires)
and yall can argue over wheather or not to require moveable rudders on all r/c aircraft.
then let nature take it's course.
allow the ec or safety comitte to issue an event waiver for events that involve more than X mph, racing, absolute speed record attempts, things of that nature, that is good for the duration of the event sanction.



then no one would be purposefully breaking rules that were ill thought out to begin with and spottily enforced, if at all. at least those that have to do with actually flying, and not just an administrative rule.

and for your information, jim, i have flown r/c since 63, about 20 more years than yerself, so i just imagine that i have seen a bit more than you. there were also a few years of ff and control line before that, as well.
and get yer reading glasses out, i said all but one of the 4 gas fires i saw, in the last 3 years, were batery ignited, the other was a backfire into a gas loaded cowel on start attempt.
and while you may not know this, gasoline has a much lower threshold of ignition than jet a, so it is MUCH easier to ignite.

Jim,

You are coming into this discussion four years after I was involved in doing a great deal of work on the last two JPO turbine waiver proposals. So don't tell me I need to do more work. Every time we (the turbine community) propose workable solutions they get tabled. Some of us don't feel that speed is the issue that causes the most problems. This was addressed with the latest document form the TRC, it attempts to shift the emphasis away from the airframe and onto the pilot. Ultimately it is the mass of meat between the pilot's ears that is there to prevent any type of accident. Accidents happen in full scale all the time, every day you can follow the list of crashes on the NTSB website they range from minor accidents where someone departs the runway to impacts causing loss of life. It is ludicrous to have the opinion that just because they are models we should not be crashing them. I contend that the safety awareness level has increased sufficiently that the incident rate of crashes has decreased in the turbine community. I also belive that the airframes, and all the systems on our airplanes are far better maintained than the aircraft in most other facets of this hobby.

You sound like you want turbines excluded from the AMA "umbrella". Specifically why? Forget about the powerplant for a minute and consider this, and if you can truthfully answer it, What would YOUR reaction be if the type of airplane YOU currently fly was the one that was catching all the heat right now?

mongo

I like the philosophy of the post. Just wonder tho how the speed limit would be enforced? I think it could be enforced similarly to the transmitter crystal change...honor system...well just a thought

BTW IMO I think 275 mph ground speed might be a viable limit if such a limit is ultimately required...200 is just too slow.

That is EXACTLY what the new set of turbine regulations did. Puts the speed issue on the honor system.

Hi David

I agree that the jet pilots, on the whole, fly in a much safer way than the bulk of the hobby. The problem is that not everyone acts in the same manner. There are always exceptions to the rule. The turbine waiver and the rules it imposes on them are aimed directly at those individuals.

Kevin Greene has made a very compelling case in this forum against the T/W rule. In looking at turbines as an outsider, it would seem to me that maneuverability is a goal to be pursued. I can see where that would make flying turbines substantially more enjoyable. At the same time, I can see where some want to “go fast and turn left�. Racing, of course, is banned by the rules. I can also understand that some of the waiver holders want bigger planes. Again, something that is banned to the waiver holders. It has become apparent that some of the issues with jets are going to remain unresolved, or be resolved in a way that makes some waiver holders unhappy. I think that Steve Ellzey’s statement to the EC that he felt 90% of the JPO members would support the new package is probably correct. That leaves 10% that are going to be unhappy.

The 200 mph rule is part of that package, but, no way exists to enforce the rule in the new package. What do you propose? I think it is apparent that no one is capable of judging the speed of a model accurately just by looking at it, and even if a few can, the vast majority can not. The T/W rule has been largely ignored and that fact has been used to support the need for enforceable rules.. such as a speed limiter.

I think that many of us have over-reacted to Dave Brown’s column. At the field, I asked several people if they had read the column. Most had not, the balance that had thought it was about technology in general and did not see it being aimed specifically at turbines. If you can find a few people that are not aware of the controversy, and not influence their reading yourself, you may get a surprise.

Oh, and said tongue firmly in cheek, the statement that turbines have more of a fire risk, and other aircraft have other issues in a crash struck me as funny. The specter of being hit by a jet at 200 mph AND having the opportunity to be cremated in the same incident did not make me feel any better about the risks involved with jets. Said another way, it is not at all useful to point fingers at other aspects of the hobby.

IF, IF< IF a reliable speed limiter were available, would you support it’s use universally on planes that are capable of speeds in excess of 200 mph as an acceptable way to enforce the proposed rules?

JR

The speed limit is based on airspeed. There are no concerns about a plane in vertical dive reaching terminal velocity with zero thrust (speed limiter activated), and pulling level with a tail wind that might increase the ground speed to some larger number. The ground speed is not an acceptable measurement for several reasons, the least of which is not the ability to accelerate straight down at zero ground speed and then pull level. No one has suggested cops or radar guns. The question has been asked about speed limiters being accurate to +-20 mph and the answer was "no problem". Couple that with a 30 mph tail wind and you have close to 250 mph ground speed.

Just for the record, changing frequencies has the force of law behind it. The FCC forbids it in most cases. There are some exceptions.

JR

JR,

In fact there does exist one speedlimiter that I DO trust and DO use, BUT.....it is integrated into the ECU for the engines that I fly and rep for. I personally don't like a 200 mph lmit but if that's what it takes to make it where I can keep flying my jets I can live with that. I have 2 airplanes right now that will break 200 mph I do not fly them at the 200 mph speed all the tie but lets face it jets are supposeed to go fast. I also enjoy the fact that several of my jets are very aerobatic and I tent to fly them slower. I also feel that in some respects the jets are safer than prop planes, you have to really try to get your finger into the engine.... although that HAS happened. I don't mention the other aspects of the hobby to try and point fingers at anyone, just consider that from my perspective there are other facets of this hobby that are just as dangerous. This whole AMA discussion seems to be based around some catastrophic incident happening and the thought that it will essentially wipe out aeromodelling with the insueing media blitz. I still say that it is just as possible that the NEXT time a model heli crashes and kills some poor gu on the flight line, or the NEXT time that a trainer hits some guys chest could have equal results. Fact is neither of those incidents scarred our hobby immensly, why would a fire, or some other form of property damage?

If a fire were to destroy one house, it would probably be pretty much ignored. If it were to burn 10, it would make the news. If it were to burn a hundred, that is where we have a genuine problem. Of course, we can say the same for a smaller prop plane hitting a bus full of kids and causing injuries or death. The simple fact is that this is not a risk adverse hobby. Most of us realize that there are risks involved and most do something to minimize the risk. The setbacks required for pylon come quickly to mind.

We are all in this together. I am sure that somewhere along the line, some guy flying indoor rubber fell off a ladder trying to retrieve his plane from the rafters. Nothing about this hobby is without some risk.

I, for one, do not want to see jets banned, or restricted more than absolutely necessary. I see the entire controversy as realitively minor. Either RELIABLE AFTERMARKET speed limiters will become available, or they will not. If they do, you can be sure the future holds them in store for the wiaver holders. If not, some other less desirable way of limiting speed is going to be imposed. T/W sucks, but, it may be the stop-gap. Unfortunately, the honor system is not likely to work, even if it is implemented. Keep a simple fact in mind. The average IQ is 100. That means that half the population has an IQ under 100, and all that that implies.

JR

BTW, keep your fingers out of the BACK of that turbine

This is all much ado about nothing, that is the current system we have right now. And in order to have this system we need viable speed limiters.

Does anyone know who the manufacturers were that called the EC? And another thing, everyone keeps saying that the units are hard to program and do a bunch of stuff, did the minihobby unit really have any additional features than spped limiting??

JR

????? Sorry but straight down speed is still considered relative to ground... Try again...


question:


Does anyone think or know whether a jet model, not a craft specifically design to do so, can surpass 275 mph terminal velocity without power?

But...It is still on our honor to comply...No regular inspections that I know of...

Quick ? for you all. Do r/c airplanes fall under FAA rules with reference to speed? If so then the limit is already set at 250kts!

Not necessarily true. Consider that the mean will test at 100 exactly and therefore there will be less than 50% above or below the average of 100...

In 1960, USAF Col. Joe W. Kittinger of the U.S. Air Force made an experimental jump from 102,800 feet. Though his stabilization chute opened at 96,000 feet, he continued to accelerate for 6,000 feet more before hitting a peak of 614 miles an hour. If a falling body as dirty as a human bundled up to survive the extreme cold nearly 20 miles up, with a drogue to boot, can reach a terminal velocity 90% the speed of sound it should be a piece of cake for a sleek jet model. 'Course the air is pretty thin up there............

Abel

ya know, we use the honor system for everything else. 55#weight limit, weight limit in pattern and scale competition.
when is the last time ya saw anyone with a big airplane at a fun fly, or just a day at the field asked to verify that his bird was under 55?
same for patern competitions, no one is asked to prove thatheir bird is iin spec as to weight. same goes for heli competitions.
i fly F1B, wakefield rubber, and have never been asked to verify that the motor rubber i use is not over allowed weight. and i have never even considered the possibility that someone elses motor might be over weight.
if i was a waivered turbine pilot, it would be quite a bit insulted by all these statements that imply that turbine pilots are not to be trusted, and are less able to use the honor system than other classes of pilots.

At that altitude, he was ABOVE the speed of sound, but it was only possible because the atmosphere is so thin at that altitude that it offers little or no resistance (as evidenced by the fact that he continued to accelerate with the drouge deployed).

"Down here" below 10,000, a human is not going to go much above 120... it would take a very clean model jet to exceed 200.

Good point

Not considered often but the speed of sound is faster at sea level than 102,000 ft

DavidR,
I am getting mightily tired of hearing how much smarter, safer, righter, and better you, Augiep38, Mongo, and the other jet jocks are. I grow weary of being told how rotten the rest of the modelers I play with are. I am sorry I have not been there to buy things from you and help you make your living for the last few years. Too bad your goals and mine don't seem to be the same, but that is life. I do not wish to provide you 'people' any more cheese to go with your constant whining about rules you and your customers don't even bother to follow! I am sick and tired of trying to find a middle ground only to have any suggestion shoved down my throat by some hyphenated people. In fewer words, I have had enough.

Congratulations on a job well done! I did not want to see turbines go away because I have enjoyed the show put on by many of my friends. However, your attitude and that of the others here who have decided to make this a personal crusade with their attacks rather than a discussion about serious safety issues has finally penetrated and helped me decide that I was in error. Today I think the turbine crowd represents the most arrogant bunch of well heeled self centered people I have ever had the displeasure to be associated with. I intend to share my thoughts with as many as I can to insure that the attitude and approach to safety and other modelers that has been shown here is well and widely known.

I will begin writing letters suggesting that we simply exclude turbines from the AMA, its events, and its coverages. If you guys are so safe, get your own insurance. You folks claim to have lots of enough money, so go buy and maintain your own airfields.

? What gives Jim...Come on get a grip...Heck you sound like me...err...Did I say that outloud? Hope nobody read that[X(]

[sm=confused.gif]

According to rec.skydiving FAQ "However, by diving or "standing up" in free fall, any experienced skydiver can learn to reach speeds of over 160-180MPH. Speeds of over 200MPH require significant practice to achieve. The record free fall speed, done without any special equipment, is 321MPH. Obviously, it is desirable to slow back down to 110MPH before parachute opening."

If a falling human body can do it, I think a model jet could easily exceed 200 mph in free fall by a wide margin. Think about it this way: the motive force on a body in free fall is equal to its weight, ergo the 'thrust' to weight ratio = 1. Can an aircraft with a t/w = 1 exceed 200 mph?

Abel

Are you serious?

Hhhhhhmmmmmmmm!!!!!!!!!