Fire Extinguishers

[FastEddieB]

Yesterday a Cirrus SR20 crashed. The pilot survived but the passenger, his wife, may have but for the ensuing fire. Horrible to even contemplate.

 

My Cirrus came with a fire extinguisher, my Sky Arrow didn't, and I have yet to install/carry one.

 

Part of my reasoning is that the engine and fuel are both above and/or behind the pilot and passenger, and would be impossible to hit with an extinguisher anyway. Still, it would be nice to have a small, compact extinguisher for a smoldering electrical fire in the panel or cockpit.

 

Thought? Recommendations? Links?

 

Thanks!

[Jim Meade]

AC 20-40D Hand Fire Extinguishers for use in Aircraft

 

http://www.faa.gov/documentLibrary/media/Advisory_Circular/AC%2020-42D.pdf

 

Fairly short. Much applies to larger aircraft but the principles may be of use.

 

"3. How to Locate and Mount Hand Fire Extinguisbers in Small Single Engine and

Multiengine Aircraft.

a. Locate hand fire extinguishers so that they are easi ly accessible to the, flight crew and

the passengers.

b. Do not allow hand fire extinguishers to lie loose on shelves, seal back pockets or

seats. Properly mount the hand fire extinguisher to the airframe structure.

c. Aircraft structure and extinguisher mounting brackets should be capable of

withstanding the inertia forces specified in paragraph I c above."

 

There are many FAR references but most are for Part 121 and 135 aircraft and the systems are designed for larger planes so they seem to be of limited applicability.

 

[FlyingMonkey]

An electrical fire can spread quickly, I'd get something for sure.

[FredG]

Aviation Consumer had an article on this in December, 2008. Link below. If link fails, you can search "Aviation Consumer Fire Extinguisher" and find it. Full article can also be found on the H3Raviation web site under the "In the News" tab.

 

http://www.aviationconsumer.com/issues/38_12/safety/5851-1.html

[Jim Meade]

It would seem logical that a fire extinguisher should be reachable from the seated, belted position and would ideally be able to be taken out and used with one hand.

[Roger Lee]

It isn't just for in flight emergencies, but ground based fires too. Electrical or fuel. It should (required or not) be in all planes and you should know the proper way to use it. When I got my last plane inspected by the DAR for its LSA registration the DAR wanted to see where it was in the plane. I keep and replace all my customers old extinguishers with a compact 5 B-C with an external pressure indicator. It would be very simple to make an engine extinguishing system for the CT and many other planes with a few simple fittings from the hardware store. I had an acquaintance many years ago die from an in flight helicopter fire. He burned before he could get on the ground. The engine in the back and lots of plastic to burn. No firewall protection. Another good reason if some SW's out there don't have the firewall blanket installed.

After a few years yank it out of the plane and put it in the shop and spend $18 on a new one. It most likely won't be bad, but it's a better safe than sorry attitude since most don't know how to maintain or inspect an extinguisher. In the fire departments most use the older extinguishers for training fires then re-charge them and yes we had extinguisher failures and so have other departments.

[Jim Meade]

BTW, here is an FAA treatise on Flammability Properties of Aircraft Carbon-Fiber Structural Composite.

http://www.fire.tc.faa.gov/pdf/07-57.pdf

 

It is pretty abstruse but the common theme seems to be that it is the resin that burns, not the fiber, and that the pressure of the resin burning expands the fiber and has an effect on structural integrity. It burns at a much lower temperature than does aluminum, but maintains structure as it does. So, it still looks like an airplane but it's not as strong.

 

What I took away from this is that if the airplane burns I'm in pretty bad shape. I will select an extinguisher based on fires in upholstery, wire and wiring, gasoline and other materials such as baggage that are combustible and not worry quite so much about putting out a fire that will feed on the carbon fiber itself and melt the tail off.

 

If anyone has different ideas, I'd be glad to hear them.

[Roger Lee]

Water is class "A" combustible. Like paper, wood, grass and the such.

 

Class "B" is flammable liquids like fuel and oil. Use no water because it spreads it and the extinguisher should be a dry powder.

 

Class "C" is electrical. Once power to an electrical line is shut off it is just a class "A" fire. We don't usually use water on energized electrical lines, but 12V isn't an issue.

 

Water is the best for absorbing heat and reducing the fires ability to form vapors that will burn, but isn't good for energized electrical or flammable liquids and it's heavy.

 

The B & C rated extinguisher is recommended for an all purpose flammable liquids and or electrical fires, but doesn't have much in the way of cooling to reduce vapors, so many times you need a little extra to keep the flames at bay until there is enough cooling to reduce vapors beyond re-ignition. This is where lay people get in trouble. Lack of experience with extinguishers and too low a rated extinguisher to finish the job due to lack of experience. A UL rated 5 B-C for us is a good size that should be able to take care of almost any emergency where an extinguisher would be useful. I keep two 40 B-C's in my hangar and a water extinguisher.

[Jim Meade]

BTW, the FAA does not recommend a dry chemical extinguisher. They strongly prefer a halon based extinguisher (although they don't like halon itself for the environmental issues). See AC 20-40D above.

The H3R extinguishers I saw that are rated 2BC are about $140 or so. Pretty hefty price compared with a dry chemical type.

The FAA doesn't like dry chemical because it can put you IFR inside the cockpit.

There's little doubt in my mind that any good extinguisher is better than none and that the physical effects of inhaling the stuff is a lesser evil than falling out of the sky in a burning airplane (especially one that dangles from it's chute letting you roast until it burns the risers off )

[Roger Lee]

A Halon inside a closed environment like a cockpit can cause anything from dizziness, loss of consciousness to asphyxiation as it displaces oxygen. Your cabin would need to be well ventilated. Halon has been banned in many places where it could be used inside because of the O2 issues with people.

I would bet a bigger majority of fires happen on the ground and I wouldn't want to use either extinguisher in a cockpit unless it was a last ditch effort before I could get on the ground. I couldn't find any real aircraft fire statistics, but I would bet that deaths in small aircraft from an in flight fire are very rare. Far more fires from crashes and on ground fires.

[Jim Meade]

The FAA agrees that halon is no good, but says it's better than the alternative. Did you read the AC? It's pretty thorough and probably in terms an old firefighter would relate to.

 

You may be right the most fires happen on the ground. That is a good point. As far as using one in flight, I'd use an extinguisher and other procedures as soon as possible if there was a fire in flight to try to stop it when it was small. Lithium batteries are an in-flight question that comes to mind.

 

On the ground, I agree with you that a big BC extinguisher sounds good. One of my questions is where do I carry one? I'd want to be able to reach it while strapped in, if possible. My plane didn't come with one so I'm going to add it. Back of the seat doesn't impress me. Bashing around the cockpit doesn't excite me. Jamming the rudder pedals sounds like a bummer. In the foot locker is not accessible in all cases. I have some ideas.

[Roger Lee]

FD put them behind the left side of the passenger seat. Unless your a little flexible guy and there is a small person in the front seat and it is forward some I don't see many getting to theirs in real life in flight and may have a delayed response on the ground.. I put mine in the floor compartment. easy for anyone to get to in a hurry, on the ground or in the air. The last thing you want to do is spend time wrestling with something in the cabin when the fire may be inches away. Quick access and deployment can be critical to success at saving property and saving you own skin.

[FastEddieB]

A couple threads on the topic recently cropped up on the Pilots of America site, and it reminded me I started this thread but never thanked everyone for their input.

 

I'll probably go with the smallest Halon aircraft unit available. They seem to be just over $100. Something like this...

 

http://www.chiefaircraft.com/hln-a344t.html

 

I think I can mount it so both pilot and passenger could reach it in an emergency.

 

Most of the combustibles - engine, fuel, etc. - are above and/or behind the cockpit, totally inaccessible in flight.

 

But the battery is in the nose cone, ahead of my feet. And, of course, there are all of the electrics and electronics in the panel and cabin. Those would be the kind of ignition sources I'd have some chance of dealing with.

 

So, thanks again - I did not mean to ignore you guys!

 

[Roger Lee]

I'm not a Halon fan and many places over the years have quit using them. It works poorly in open air situations especially if there is a breeze. It displaces oxygen in closed spaces and it takes more expertise to use it properly and they usually don't last as long as a dry chem. You ought to pick up one of the First Alerts 5 B-C dry chem (or some other Mfg if you like). They are readily available, easy to use and work better in adverse environments. There was a thread a while back talking about our extinguishers. It's $20 verses $100. You have to match the need with the use and persons training.

[FastEddieB]

Thanks.

 

It's clearly a complicated and contentious debate, and one where you have far more experience.

 

Still, on the basis of FAA recommendations, I'm still leaning to the halon for my aircraft.

 

Here's a link to the (very long) FAA document on the matter:

 

http://www.faa.gov/d...r/AC 20-42D.pdf

 

Many on the Pilots of America site post drawbacks to conventional extinguishers being used in planes.

 

Here's a link to that thread:

 

http://www.pilotsofamerica.com/forum/showthread.php?t=66139&highlight=extinguisher

 

Open to any comments.

[FlyingMonkey]

Eddie, make sure you open every window, vent, and cabin heater you have before firing off a halon extinguisher in the cockpit. If I had an O2 bottle in the cockpit I'd put the mask or cannula on as well (not near open flames of course!).

[FastEddieB]

This from an AOPA article:

 

"Dry chemical extinguishers, widely available in hardware stores, are not a wise choice for the cockpit. The smothering agent used in the bottle is very corrosive and will eat away at avionics, possibly causing thousands of dollars in unnecessary damage. In addition, the powder that is discharged will easily stick to aircraft windows, potentially blocking vision."

 

Also:

 

"Halon is not very toxic; humans can go without any effects from Halon up to 77% concentration of total air molecules."

 

Full article here:

 

http://www.aopa.org/Pilot-Resources/PIC-archive/Aircraft-Ownership/Fire-and-Fire-Extinguishers/AOPA-Online-Members-Only-Aviation-Subject-Report-Fire-Extinguishers-An-Overview.aspx

[Anticept]

There are foam extinguishers...

[WmInce]

The standard fire extinguisher used in cockpit airliners is exclusively Halon.

[FredG]

Eddie, the statement you quoted, "Halon is not very toxic; humans can go without any effects from Halon up to 77% concentration of total air molecules." makes no sense to me (I know, you are only the messenger).

 

If 77% of air was displaced by Halon, and the remaining 23% was still made of air (ie, 21% oxygen), a person would become incapacitated in seconds and die in minutes. I just don't understand the claim.

 

BTW, I keep a small Halon extinguisher in my CT. If I used it, I would open every source of uncontaminated air available to me.

[Roger Lee]

Eddie,

 

When you are on fire let me know if you are worried about a little corrosion. Blow it out or wash it off your burnt up and trashed engine and I think you'll be okay. Who said the fire was going to be in the cockpit? Halon good for in closed spaces where humans shouldn't be when discharged. Halon isn't as good outdoors like when you have a fuel fire. It also lacks any distance capability.

[Anticept]

If you have to use your fire extinguisher, then your plane probably isn't coming out.

[Roger Lee]

Hi Anticept,

 

You got it.

All you want is the fire out if your out of the plane and it's on fire and all you want to do in flight is live long enough to get on the ground and bail. Corrosion, who would have thought anyone would care when your on fire. Halon, displaces oxygen so you can't breath or worry about a little corrosion and that's on slightly possible. Halon isn't even allowed in some occupancies any longer. Leave it to a bunch of non fireman on POA to worry about the mundane and minor issue.

[FastEddieB]

Thanks to all who provided input and links.

 

With such varied advice, someone is going to end up feeling like their advice was ignored - that it not the case, and I tried to consider all the info provided while making my choice.

 

In any event, for just over $100 I ended up with:

 

 

Agonized over where to put it. My Sky Arrow is very narrow and I could not find a location where both Karen and I could reach it.

 

So, it ended up here:

 

 

It allowed me to only drill through a (rather thick) carbon fiber "glove box" door - I was really hesitant to drill any structure beyond that.

 

The Sky Arrow has all the fuel and engine behind or above and behind the passenger. The only fire an occupant would have any chance of dealing with would be one in the panel or spreading back from the battery in the nose. I guess if the fire was spreading forward and down from an engine/fuel fire an extinguisher might slow it down, but things would be very, very far gone at that point.

 

Anyway, thanks again for all the input!

[WmInce]

Thanks to all who provided input and links.

 

With such varied advice, someone is going to end up feeling like their advice was ignored - that it not the case, and I tried to consider all the info provided while making my choice.

 

In any event, for just over $100 I ended up with:

 

 

Agonized over where to put it. My Sky Arrow is very narrow and I could not find a location where both Karen and I could reach it.

 

So, it ended up here:

 

 

It allowed me to only drill through a (rather thick) carbon fiber "glove box" door - I was really hesitant to drill any structure beyond that.

 

The Sky Arrow has all the fuel and engine behind or above and behind the passenger. The only fire an occupant would have any chance of dealing with would be one in the panel or spreading back from the battery in the nose. I guess if the fire was spreading forward and down from an engine/fuel fire an extinguisher might slow it down, but things would be very, very far gone at that point.

 

Anyway, thanks again for all the input!

 

Eddie,

 

Which extinguisher is that?

A link for a closer look would be appreciated.

 

Thanks in advance.

 

Bill . . . . .