Q. Canadian Homebuilt: Fire Extinguishers - Halon

the guy on ebay that has them once in a while is
called firebruiser from Oshawa That is where I got
mine.

Thanks. I'll keep an eye out for it.

From the Cars it apears that you can use anything you want.

http://www.tc.gc.ca/aviation/applica...n/1298_Att.htm


Personally I think that dry chemical is most effective and that's what
I have in my plane. If I remember correctly it's rated 5BC that means
an expert could put out a 5 square foot gas fire with it. It weighs
about 2lbs.

Hello All,

This question is regarding Canadian regulatory issue with importing a Halon
fire extinguisher.

I'm building an RV and am considering fire extinguisher options. Was about
to buy a Halon 1211 2lb fire extinguisher on ebay until I looked up the
legalities of importing it to Canada. Seems you can't anymore, even if it is
recycled Halon.

I know of homebuilders who use household CO2 fire extinguishers. However,
these devices, if discharged in a closed space will:

- decrease or obscure visibility
- reduced breathability wrt Halon discharge
- by-products can corrode aluminum if not cleaned off promptly (discharge
remains in faying aluminum layers.

The cheap household brands will self discharge in storage if the compartment
gets too hot (e.g. bubble canopy, on the ramp, standing in the sun).
Possible replacement for Halon is Sapphi
http://www.tyco.com/tyco/press_relea...l.asp?prid=718
however, I have not seen specific applications for aviation.

By the way, in Canada we are required by Transport Canada to carry fire
extinguishers in homebuilts.

What type of fire extinguishing agent to you use or plan to use? Looking
for comments and suggestions from Canadians as well as others familiar with
this issue. Thanks.



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References:



http://www.cbsa-asfc.gc.ca/E/pub/cm/...d19-7-2-e.html

In summary, the above regulations says:
5. The Ozone-Depleting Substances Products Regulations prohibit the
importation of:

d) any of the following products that contain any chlorofluorcarbon
or bromofluorcarbon from a place outside a party to the Montreal Protocol:

(3) fire extinguishers;




Transport Canada does not recommend replacement of Halon for aircraft:

http://www.tc.gc.ca/CivilAviation/co...ars/AC0179.htm

"to date none of these agents have been approved as a substitute for Halon
hand-held fire extinguishers used on board aircraft."

Rich S. wrote:

Establishing and maintaining the required concentration of Halon is
difficult, if not impossible, in an open space. Even closed environments
such as sealed buildings are difficult to permeate. It is likely impossible
under an aircraft cowling when the plane is moving.

I disagree. Have you ever used a Halon fire extinguisher? Back in the
Reagan era when the defense departement had a lot of money and Halon
hadn't yet been restriced, we were given training where we used large
Halon hand extinguishers to put out diesel fuel fires set in pans
outside.

If the Halon is removed and there is still a source of ignition, the fire
will take up right where it left off.

If you've got a cabin fire, that's a horse of a different smell.


With a flood system and a relatively closed space it takes a long
time for the Halon to disapate. Try lighting a lighter in a space
near where halon has been discharged.

Of course, much of what you said also applies to CO2. If the CO2
doesn't cool down the metal (which admittedly it has a higher
capacity to do than Halon), then you have the same (actually larger)
reignition problems.

the key statement is...

"It is likely impossible under an aircraft cowling when the plane is
moving. "

For this application it is a waste of weight, money, and time.

"Ron Natalie" wrote in message
m...
Rich S. wrote:

Establishing and maintaining the required concentration of Halon is
difficult, if not impossible, in an open space. Even closed environments
such as sealed buildings are difficult to permeate. It is likely
impossible under an aircraft cowling when the plane is moving.

I disagree. Have you ever used a Halon fire extinguisher? Back in the
Reagan era when the defense departement had a lot of money and Halon
hadn't yet been restriced, we were given training where we used large
Halon hand extinguishers to put out diesel fuel fires set in pans
outside.

If the Halon is removed and there is still a source of ignition, the fire
will take up right where it left off.

If you've got a cabin fire, that's a horse of a different smell.


With a flood system and a relatively closed space it takes a long
time for the Halon to disapate. Try lighting a lighter in a space
near where halon has been discharged.

Of course, much of what you said also applies to CO2. If the CO2 doesn't
cool down the metal (which admittedly it has a higher
capacity to do than Halon), then you have the same (actually larger)
reignition problems.

"Ron Natalie" wrote in message
m...
Have you ever used a Halon fire extinguisher?

Yup. I have fought actual aircraft fires using Halon, Dry Chemical (both
"Purple K" and "Super K"), Protein foam, CO2, etc., etc. For a picture, see
http://temp.corvetteforum.net/c4/elw...mp/oysters.jpg or
http://tinyurl.com/csndg . That's me in the middle next to the pilot's
seat. All those little black dots are fresh oysters he was bringing back
from Canada. The white stuff is Dry Chemical - 1,500 pounds of it. It
wouldn't stop the fire until we covered it with foam. Items like the burning
tires would reignite the gasoline behind us after we had moved the hose line
past. Had to replace my bunking outfit after that one - too many burn holes
to repair it.

With a flood system and a relatively closed space it takes a long
time for the Halon to disapate. Try lighting a lighter in a space
near where halon has been discharged.

I spent several years inspecting, discharging and signing off fixed Halon
system in computer rooms, satellite communications buildings, and one
180,000 sq. ft. building for Boeing that I can't even talk about. There are
no areas on a light aircraft which are sealed tightly enough to establish or
maintain a proper concentration of Halon. You can "overkill" a simple pan
fire with a portable extinguisher, but that won't work on an engine
compartment fire when you're in the cockpit.

Halon is a wonderful product, for it's purpose.

Of course, much of what you said also applies to CO2. If the CO2 doesn't
cool down the metal (which admittedly it has a higher
capacity to do than Halon), then you have the same (actually larger)
reignition problems.

Some other factors must be considered with CO2. Being heavier than air, it
tends to settle in a low spot - very important in ship fires. Halon diffuses
throughout the space. I'm not sure how the Latent Heat of Vaporization
compares between Halon and CO2. In either case the cooling capability is a
very minor effect when it comes to extinguishment. If you want cooling, use
water. If you want to secure the area and prevent reignition, use foam.

In a three-dimensional fire such as an aircraft fire, all bets are off. Even
foam may not prevent reignition. Trust me - it is scary to be wading in Jet
A trying to plug a leaking tank when the stream coming from the tank keeps
igniting. Even in a drill. 8-}

Rich S.

Rich S. wrote:
...

Some other factors must be considered with CO2. Being heavier than air, it
tends to settle in a low spot - very important in ship fires. Halon diffuses
throughout the space.

Recalling Avogodro's law, Isn't Halon also heavier than air?
In fact, isn't it heavier than CO2?



--

FF

wrote in message
oups.com...

Recalling Avogodro's law, Isn't Halon also heavier than air?
In fact, isn't it heavier than CO2?

Well, I don't remember. I know it's typically discharged from the high point
in an enclosed space through specially designed diffuser nozzles, so what
you say may be correct. I seem to remember that, like air, it is a
homogenous mixture of gasses and tends to diffuse throughout the atmosphere.
Maybe that's why some are concerned about the "Ozone hole" and Halon
affecting that in the upper atmosphere.

It's been a long time since I've studied any basic chemistry and I didn't
know that much about it then. If different gaseous elements tended to
separate out, wouldn't Nitrogen separate from Oxygen in the atmosphere? But
we know it doesn't. I don't know enough to hold up my side of a technical
discussion based on Avocados. I remember that we used to put sniffers at
different heights inside buildings where we were discharging Halon systems
and would measure the concentration at all levels.

Rich "Getting old is no job for a sissy!" S.

Rich S. wrote:
...
It's been a long time since I've studied any basic chemistry and I didn't
know that much about it then. If different gaseous elements tended to
separate out, wouldn't Nitrogen separate from Oxygen in the atmosphere?

Oxygen and Nitrogen are close to having the same MW which minimizes
stratification effects. But even relativley heavy molcules like
styrene will not stratify measurably over a height of a meter or
so, given sufficient time to diffuse through the volume.

Diffusion rate rather than desity differences dominate uneven
distributions of gasses in most situations. IIRC diffusion rates
are inversely proportionate to the square of MW but bouyancy
is directly proportionate.

--

FF

wrote in message
ups.com...
Oxygen and Nitrogen are close to having the same MW which minimizes
stratification effects. But even relativley heavy molcules like
styrene will not stratify measurably over a height of a meter or
so, given sufficient time to diffuse through the volume.

Diffusion rate rather than desity differences dominate uneven
distributions of gasses in most situations. IIRC diffusion rates
are inversely proportionate to the square of MW but bouyancy
is directly proportionate.

Anything you say, Fred. BTW, can I have two slices of lime with that and -
don't forget to salt the rim!

Rich S.

Rich S. wrote:
wrote in message
ups.com...

Oxygen and Nitrogen are close to having the same MW which minimizes
stratification effects. But even relativley heavy molcules like
styrene will not stratify measurably over a height of a meter or
so, given sufficient time to diffuse through the volume.

Diffusion rate rather than desity differences dominate uneven
distributions of gasses in most situations. IIRC diffusion rates
are inversely proportionate to the square of MW but bouyancy
is directly proportionate.


Anything you say, Fred. BTW, can I have two slices of lime with that and -
don't forget to salt the rim!

Rich S.


There are a few Aqueous Fire Fighting Foams (AFFF not sure if that is a
recognized acronym or just Sales Hype)systems out there now to replace
Halon in Auto Racing applications, has anyones heard whether one of
these might be a viable alternative?

Mike Butler