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Aircraft Fire Extinguishers

Started by scooter, October 22, 2008, 09:55:57 PM

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scooter

Today I took my aircraft fire extiinguisher for its annual, it is the ABC type. The inspector told me that this is a bad type for aircraft because it will disperse 2+ pounds of powder in the confines of the cockpit in a short time. The poweder will destroy the avionics, assuming it already isn't by the fire, as well as incapacitate the crew with clouds of powder obscuring the windows. He said we would probably lose the crew and the aircraft because of the crew incapacitation. Any fire guys out there know if this guy was just trying to sell a clean agent extinguisher or is he right on. CAP doesn't specify the type of extinguisher we should carry or prohibit any type either. :(

Pumbaa

I forgot the name of the heavier than air gas they used to use in computer rooms, it would smother the flames and not harm equipment.  Of course since it 'harmed the ozone', it was banned.


IceNine

"All of the true things that I am about to tell you are shameless lies"

Book of Bokonon
Chapter 4

IceNine

For what its worth when I worked at the FBO we had 2 types of extinguishers

ABC for the buildings, trucks, and other.

And a Yellow extinguisher that was BC that was only to be used on A/C fires. 

And I can tell you that in a small area like a cockpit, that dust will be debilitating for breathing and sight specifically
"All of the true things that I am about to tell you are shameless lies"

Book of Bokonon
Chapter 4

SarDragon

Quote from: Pumbaa on October 22, 2008, 10:58:27 PM
I forgot the name of the heavier than air gas they used to use in computer rooms, it would smother the flames and not harm equipment.  Of course since it 'harmed the ozone', it was banned.

They used various forms of Freon until the ozone issue came up. Now it's Halon. Both are heavier than air, and suffocating agents in confined spaces.

PKP, and similar powder agents, will not "destroy" avionics. It is difficult to clean up, however. Halon does not have that problem.
Dave Bowles
Maj, CAP
AT1, USN Retired
50 Year Member
Mitchell Award (unnumbered)
C/WO, CAP, Ret

lordmonar

PATRICK M. HARRIS, SMSgt, CAP

EMT-83

I've been in lots of fires, but never inside a burning aircraft. Ranks right up there with my worst nightmares. But back to fire extinguishers...

Your extinguisher won't dump 2 pounds of powder into the cockpit when you squeeze the trigger. Hopefully, the agent would be applied to the fire in short bursts, and not sprayed into the air. Visibility will be restricted, but I wouldn't think to the point where the windows are totally obscured. I'd be more worried about smoke.

The powder is irritating, but won't kill you. Again, I'd be more worried about smoke. Dry chemical is highly effective, especially for incipient stage fires. I've held vehicle fires at bay with an extinguisher, awaiting an engine company, by careful application.

Some agents can be corrosive, if not cleaned up in a timely manner. Safely landing the plane would definitely be a higher priority.


RiverAux

I suppose it comes down to whether or not using the extinguisher while in flight would cause so much damage that you're going to crash immediately because of it.  If the powder causes long term damage but nothing right away, then the trade off of the plane vs surviving the fire is easy to make. 

The thing is that in the airplane you could have all sorts of different types of fire and the ABC extinguisher is probably the best all around choice for this situation. 

Bear Walling

Consult the National Fire Protection Association (NFPA) 408: Standard for Aircraft Hand Portable Fire Extinguishers. This standard specifies requirements for the type, capacity, rating, number, location, installation, and maintenance of aircraft hand portable fire extinguishers to be provided for the use of flight crew members or other occupants of an aircraft for the control of incipient fires in the areas of aircraft that are accessible during flight.

When to use (or not use) Dry Chemical Extinguishers?

Dry chemical extinguishers can be quite corrosive to metals such as aluminum and are also potentially abrasive. ABC extinguishers are much more corrosive than BC extinguishers because the ammonium phosphate agent can undergo hydrolysis to form phosphoric acid and because the molten agent flows into minute cracks.

For this reason, dry chemical ABC extinguishers are not recommended for use on aircraft or electronics such as computers, MRI scanners, and scientific instruments. Boeing has stated in a service letter "Dry chemical extinguishers can cause extensive corrosion damage to airplane structure, electrical systems, and electronic equipment...Dry chemical fire extinguishers should only be used for airplane firefighting if there are no other extinguishers available and there is imminent danger to property or personnel."

Here are some typical extinguishers and their uses:

# Halotron I extinguishers, like carbon dioxide units, are "clean agents" that leave no residue after discharge. Halotron I is less damaging to the Earth's ozone layer than Halon 1211 (which was banned by international agreements starting in 1994). This "clean agent" discharges as a liquid, has high visibility during dischage, does not cause thermal or static shock, leaves no residue and is non-conducting. These properties make it ideal for computer rooms, clean rooms, telecommunications equipment, and electronics. These superior properties of Halotron I come at a higher cost relative to carbon dioxide.

# FE-36TM (Hydrofluorocarbon-236fa or HFC-236fa) is another "clean agent" replacement for Halon 1211. This DuPont-manufactured substance is available commercially in Cleanguard® extinguishers. The FE-36 agent is less toxic than both Halon 1211 and Halotron I. In addition, FE-36 has zero ozone-depleting potential; FE-36 is not scheduled for phase-out wheras Halotron I production is slated to cease in 2015.

Choose wisely...

scooter

So... I called NHQ and talked to the guy in charge of this stuff. He said the next change to CAPR 66-1 will specify Halon fire extinguishers in CAP aircraft. National will drop ship one to aircraft needing one if it is in the consolidated maintenance program. The wing foots the bill otherwise. Have your crew chief check your aircraft fire extinguisher.  :) ABC = bad outcome.

davidsinn

Quote from: scooter on October 23, 2008, 04:35:22 PM
So... I called NHQ and talked to the guy in charge of this stuff. He said the next change to CAPR 66-1 will specify Halon fire extinguishers in CAP aircraft. National will drop ship one to aircraft needing one if it is in the consolidated maintenance program. The wing foots the bill otherwise. Have your crew chief check your aircraft fire extinguisher.  :) ABC = bad outcome.

Of all the things that get ICL's I think that should be one.
Former CAP Captain
David Sinn

heliodoc

^^^^^^^^^^^^^ :clap: :clap: :clap:

ICL for aircraft safety BEFORE uniforms??

Now there's a thought.................

davidsinn

Quote from: heliodoc on October 23, 2008, 06:28:05 PM
^^^^^^^^^^^^^ :clap: :clap: :clap:

ICL for aircraft safety BEFORE uniforms??

Now there's a thought.................

It makes too much sense so it'll never happen. Pity.
Former CAP Captain
David Sinn

EMT-83

Knowing what you have for an extinguisher is always important.

The security guard at a local condo complex got a call one day for a lady with a snake in her kitchen. He'd heard somewhere that a CO2 extinguisher could be used to freeze a snake, and since he was afraid of snakes, thought it was a great idea.

So he runs out to his security vehicle and grabs the extinguisher. He brings it into the kitchen and lets loose. Of course it wasn't a CO2 extinguisher, but was dry chemical. Powder in every nook and cranny of that lady's kitchen; cost the condo association hundreds of dollars to clean it up.

In all the commotion, the snake finds his own way out the kitchen door.

shertz

There is a great article in the latest issue of Aviation Consumer on aircraft fire extinguishers. It give all the pro's and con's of the various extinguishers and is a good read if you want to understand the basics.