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Fire extinguishers

Posted: Sun Feb 23, 2020 1:44 am
by Boatguy
I was looking at my fire extinguisher recently and discovered it's a dry powder type, whereas the FAA recommends halon or halotron. In fact in AC20-42D the FAA specifically recommends against using dry powder extinguishers in aircraft. Does anybody know why Diamond would provide an extinguisher which the FAA advises not be used?

The second thing that occurred to me was how I would use the extinguisher inflight. An electrical fire seems most likely to occur behind the panel, or in the LRU rack under the baggage shelf. Neither of these is accessible without removing panels. So in the event of an inflight fire, where do you point the fire extinguisher?

Re: Fire extinguishers

Posted: Sun Feb 23, 2020 3:16 am
by Steve
Russ:

Not sure why they would do that (expense?). Mine has a Halon extinguisher. I had to get it overhauled after 10 years, it is due again in 2021. You are correct about accessibility of the likely fire locations. In my aircraft there is a hole in the floor of the instrument panel (where the canopy gas strut attaches to the firewall), but it would be nearly impossible to get the extinguisher aimed through it in-flight. If I had an experimental, I would just make a couple of fittings on the instrument panel that would connect to the extinguisher nozzle...

I have had an electrical fire in my airplane, about 14 years ago. My COM1 radio (B/K KX-165) caught fire, during a night flight. Luckily, pulling the COM1 CB extinguished the fire. That was the scariest moment I've had in an airplane.

Steve

Re: Fire extinguishers

Posted: Sun Feb 23, 2020 4:21 pm
by Colin
WW1 pilots carried a pistol in case they caught fire.

Re: Fire extinguishers

Posted: Sun Feb 23, 2020 5:55 pm
by pietromarx
Personally, I think Colin's approach has a number of advantages. Less space required. Faster working. Better user experience. But probably best only when flying solo.

Re: Fire extinguishers

Posted: Mon Feb 24, 2020 8:44 pm
by greg
Steve wrote: Sun Feb 23, 2020 3:16 am
Not sure why they would do that (expense?). Mine has a Halon extinguisher.
Steve, I don't suppose you know the model number and/or specifications of that Halon extinguisher? My extinguisher is due for replacement and I don't want to replace it with another dry powder unit.

Re: Fire extinguishers

Posted: Mon Feb 24, 2020 10:00 pm
by Steve
Greg: I don't have the model number on hand, and it isn't on the paperwork from the overhaul. I do remember that it was manufactured by a German or Austrian company (not surprising, since my airplane was manufactured in Diamond's Austrian factory). It is similar to this one:

https://www.sportys.com/pilotshop/small ... lsrc=aw.ds

except that mine is Halon, and this one is Halotron. I found a photo of my extinguisher that shows a portion of the label (before I sent it off for overhaul):
DSCF0065.jpg
It shows that it is Class ABC, and that the agent fill weight is 1.974 Kg (4.34 pounds). I'll get you the information from the label as to Manufacturer and Model number, but I would suggest getting one in the US, since shipping will be very expensive from Europe...

Steve

Re: Fire extinguishers

Posted: Mon Feb 24, 2020 10:52 pm
by greg
Thanks Steve. I'd appreciate the model number when you get a chance, but no hurry. I'm in Australia, so the shipping will be expensive no matter where it comes from. :(

Re: Fire extinguishers

Posted: Wed Feb 26, 2020 9:22 pm
by ultraturtle
Halon is bad juju in the cockpit environment, and has been largely replaced by other ABC chemistries worldwide. It's main fire-fighting effectiveness comes from it's amazing capability to suck all of the oxygen out of ambient air once introduced. Without oxygen, fires extinguish immediately. Problem gets introduced in the cockpit environment because human beings are quite fond of breathing oxygen. While PBEs (Personal Breathing Equipment - a hood with a couple oxygen cylinders to provide roughly 15 minutes of breathing and clear vision) stationed next to these halon extinguishers mitigate the problem transitioning the phase out, halon is going the way of the dinosaur as far as aircraft cockpits go. My 2017 DA62 has a Halon bottle, and I personally cannot wait for Diamond Aircraft to wake up and smell the (lack of) oxygen and specify a different chemistry (like dry powder) for its fire extinguishers fleet wide.

Re: Fire extinguishers

Posted: Sat Mar 14, 2020 2:13 pm
by Steve
Just came across this YouTube video. For me it is hard to watch. Makes me glad that I have an extinguisher in my aircraft, two of them at my home field's fuel pumps, and another in my hangar. It also reinforces the importance of getting the agent on early in the event...



Steve

Re: Fire extinguishers

Posted: Sat Mar 14, 2020 2:47 pm
by krellis
Boatguy wrote: Sun Feb 23, 2020 1:44 am I was looking at my fire extinguisher recently and discovered it's a dry powder type, whereas the FAA recommends halon or halotron. In fact in AC20-42D the FAA specifically recommends against using dry powder extinguishers in aircraft. Does anybody know why Diamond would provide an extinguisher which the FAA advises not be used?

The second thing that occurred to me was how I would use the extinguisher inflight. An electrical fire seems most likely to occur behind the panel, or in the LRU rack under the baggage shelf. Neither of these is accessible without removing panels. So in the event of an inflight fire, where do you point the fire extinguisher?
ABC fire extinguishers are very corrosive to aluminum.