Fire season has arrived in the high country. The county I live in has just instituted a fire ban that prohibits operating any internal combustion engine without a spark arrester. Does anybody know if the muffler on my O.S. 46fx counts as a spark arrester. I ran it last night and I could't see any sparks coming from anywhere on the engine. Also, do you think there would be a real risk of fire in a crash? I found a really sweet place to fly that is a lot closer to me than the club field( 15 miles as opposed to almost 60). It's an abandoned road out in the gas patch that is on BLM land. The road is real smooth, hard-packed clay about 40' wide with a 1500'+ long straight section. Problem is, if I come down anywhere other than the road it will be into sage brush and dry range grass. I definitely don't want to be "that guy that started the great 2008 wildfire". Any comments, suggestions or similar experiences would be appreciated.

While it's possible that any heat source (such as a hot engine crashing into the dry grass) could theoretically start a fire, it's not very likely. There is no hazard from the fuel catching on fire like there is with a gasoline powered engine. Also, you don't have to worry about the spark problem with glow engines. So you should be ok. But..... (isn't there always a "but"?) don't forget you are dealing with a government entity. It would be better if you contact them first before going out there. If/when you get an "OK" to go out make sure you get the persons name that told you it was ok.

Hope this helps

Ken

With a muffler, I would not worry about starting a fire. However, the battery pack and wiring can in a crash.

You would probably be more likely to accidently start a fire by parking your vehicle over dry grass and having your hot catalytic converter catch the grass on fire. If you do fly there, I would recommend not driving off road at all.

Oly

Just my tw cents worth, I think you are more likely to start a fire with and electric. I've seen three of them go up in smoke at our field. I seen and been involved in several crashes around our filed and this time of the year, things are really dry. I've yet to see any sign of a fire being started by a glow engine. I have hit so hard that I ruptured my fuel tank on two different crashes and even then, there was no fire.

If you were flying gas, the chances would be a bit higher, but again I've saw at least a dozen gasser crashes at our field in the last couple years and no fires. We even had a turbine go down a month or so back and no fire.

Does this mean you couldn't start a fire? That possibility is always there. Sparks from metal on a rock is always a possibilitie in a crash. The couple fires that we have started around our field were the results of flying into a power line that used to go across one end of our runway. Our club opted to run about 1000' of it underground to eliminate it as a hazard. We still have lines within striking distance, but that one was across our approach.

You might check with the county to see if the airplane engines require an arester. I would doubt it, but you never know.

Don

I would also bring out a large bucket of water by the very slight chance that you started a fire, if you caught it quick, you should not have a problem.

The way I see it is this:

1) I truly believe that a muffler would be considered a spark arrester.

2) even if it isn't, the Park Ranger won't know that it's not.

"Yesser, you see that big cylinder on the side of the engine? That's the spark arrester!"

He'll never know, and in over 40 years of flying I've never seen a glow engine (with a muffler) start a fire. (I DID however see a glow engine without a muffler cause the dope-covered-balsa along side the engine catch fire, but that was because the balsa wasn't cut away to allow the exhaust to pass - but again, this was back in the 60's when we didn't use mufflers)

You would think a muffler with a baffling in it would be consider a spark arrester.
You can also term the baffling as a spark arrester, if they ask.

I've seen my go kart go down in flames without a spark becuase my kid spilt gas on
a hot engine.

Before I moved here I lived in the mountains of Calif. and worked on small engines for our local hardware store. I was also on the fire department there. For small engines or riding lawn mowers A baffel was just A screen on the muffler outlet, they seemed to work but mowers like mine tended to back fire when you turned them off and they were useless then. I have put out A fire or two from that.
Our RC club had one rule, NO GAS ENGINES during fire season and it was inforced, didn't need to be because everyone knew the danger.
I have only seen one fire started by A glow engine, it was on A soaked start up stand and the pilot let the fuel flow from the muffler when filling. On start up it sort of back fired and fired up the fuel. If it wasn't for the old carpet on the bench top no one would have noticed.
The glow engine/plane really is no problem but as mentioned the battery/switch or some of the new batteries do not take to impact too well.
My old mountain field never had A problem and we had some very hard crashes in the tall dry brush. I don't think I would worry about it at all.
OLY hit it right on too. During Deer season we put out A bunch of fires started by auto converters and tall weeds. Take A peek some night at that thing after driving for A while, they can be glowing!!!
For A fun story ask me about our old CROWN fire engine that backfired when you changed gears!!!

Overall I agree with what has been stated in replies. Yes it would be a good idea to get permission to fly there. I would hesitate to mention anything about a fire hazard since in all likelyhood whomever you speak to will NOT be familiar with the unlikelyhood of these aircraft starting a fire. Gas fuel yes, very inflamable but glow fuel not. May not be a bad idea though to have a small fire extinguisher with you anyhow. Who knows maybe you will ignite grass from your cigarette???? Wish I had a field like that that close. Enjoy.

I wouldn't be too concerned about the glow engine. If you have any electrics though, the li-po batteries could be bad news in a crash.

You may alos want to keep a fire extiguisher or two close by just for piece of mind. I doubt you'd be able to do much with them since grass and brush fires spread so fast but anything is better than nothing just in case the worst case scenario happens.

To ChuckW's remark about the LiPo batteries.... i've heard stories from several veteran fliers about someone inadvertantly mismatching electronics and overloading them on an electric plane (a newbie to electrics, not necessarily flying, who basically was drawing WAY too much current due some obscure reason I didn't quite get; I don't know electrics or their intricacies...). The end result is that the plane burned itself into a puddle of carbonized goo and the LiPo battery transformed itself into a "spark grenade" [:@] that left a 10' burn ring at the end of the field. Apparently when those things get into "overload" mode, they swell up like balloons and then BANG!!!! they start tossing flaming bits of crud everywhere. Not cool in a "severe" fire zone area [:'(]

But I also heard it was a heck of a visual object lesson for all the other electric fliers that day and that within 5 minutes after the "ring of fire" EVERYONE had a multimeter out and was checking every wire, connection, and the min/max loads across every part their planes' system!

I have managed to burn the SNOT out of my fingers when they accidentally touched the muffler on a .60 glow that I didn't realize had just been running just 5 minutes before.... that was a stupid "hot stove" lesson that I don't plan to repeat [:@] but it wasn't any worse of a burn than I've gotten from a car's manifold/cat when I had to make some quick emergency repairs on my sis-in-law's MG while it was stranded in a "not so great" neighborhood of Atlanta. It still wasn't hot enough to start a fire even if you pressed dry brush/prarie grass up against it. (...but it did hurt like a BOOGER and I sure as heck wouldn't do it on purpose!!!!!!!![:@] )

I have one friend that tried to burn down his house charging his LIPO and not watching it or using the crock pot. I saw A nice grass fire started by A gasser crashing and his LIPO sparking.
So far the best one has been A friend that crashed his big gasser, picked up the rubble and brought it home. Tossed the remains up against the house then went in to get cleaned up. Discovered why you are supposed to unplug the batteries and drain the gas after A crash, burnt A big part of the house down. This was A NICAD battery too but A short is A short.
Insurance paid the bills and even sprung for 5 grand for A new plane, that took A lot of crust to claim but it worked.[>:]

Rufcut,
There's no shortage of opinions, and this has gone totally astray of the question you asked. From what you wrote, the discussion about battery fires is immaterial since the fire regulation in your area addresses only internal combustion engines and spark arresters.

In the end, none of our opinions matter. If you get a ticket, it will be up to you to prove your muffler is a spark arrester.

I found a link to a Spark Arrester Guide on the US Forestry Service web site
http://www.fs.fed.us/fire/prev_ed/spark/sag-index.html
Follow the instructions and download a 12mb PDF for Multiposition Small Engine (MSE)

Page 11 has this definition
"A Spark Arrester—A device which traps or pulverizes exhaust carbon particles to a size below 0.023-inch in diameter, as they are expelled from an exhaust system."

Even though this document is primarily directed toward chain saws, you could potentially have to prove that no particle bigger than .023 can get out of your engine. I know I could not prove this.

How did it get to LiPo's when he never mensioned any thing at all about them, he asked about an OS 46fx?
Rufcut, If you are worried about it, get some fine copper mesh and make a cone to fit in the muffler and then you will have a spark/flame arrester.

Gray Beard, I would like to here about it.

Cheers

When I was younger I had a glow car, I started it once and it did catch fire !!!, so, yes glow fuel will catch fire and it burns so clean it's hard to see.
Just my experience, take it for what it's worth.

Carrellh,
Thanks for the link. I probably should have stated in the original post that I use Nicd batteries and although I didn't specifically ask about the fire danger from a short, it is something worth considering.
Overall, I believe a 2 stroke glow engine poses very little, if any, fire danger and the comments thus far seem to support that belief. I think I will follow The Ghost's advice and install a screen in the muffler just to be sure.
I always carry a shovel and a 5 lb. fire extinguisher in the truck but good advice anyway. I'll contact the local BLM office and see if they have any objections. I don't see why they would, but I've been wrong before.
Thanks for all the responses guys.