Q. Canadian Homebuilt: Fire Extinguishers - Halon

[RV9]

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 Sapphire:
http://www.tyco.com/tyco/press_release_detail.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.



----------------------------------------------------------------------------
-------------------
References:



http://www.cbsa-asfc.gc.ca/E/pub/cm/d19-7-2/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/commerce/circulars/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.]

"RV9" > wrote in message
...
>
> 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.

I think you may be confusing a CO2 extinguisher with a dry chemical
extinguisher. A CO2 extinguisher has no by-product other than the moisture
in the air which may be frozen by the expanding CO2. A dry chemical
extinguisher may leave corrosive residue.

You say that you are required to carry an extinguisher. I assume that the
regulation specifies the minimum rating of the extinguisher - if not the
agent. If the rating is specified and 1211 Halon is not available (try a
marine store), I would get a dry chemical extinguisher of the minimum rating
and carry it. Whether you use it or not will be apparent when the time comes
and you will easily be able to choose between corrosion and the effects of
the fire.

With my wooden airplane, I carry a small 1211 Extinguisher which I bought at
a garage sale. If the airplane catches fire, and there is dirt nearby, I
will toss the extinguisher into the fire and make tracks in the dirt. :)

Rich S.

[[email protected]]

You can watch a bit and buy one from a Canadian seller.

When one comes up on ebay.

[[email protected]]

On Fri, 15 Jul 2005 12:36:52 -0700, "Rich S."
> wrote:

>"RV9" > wrote in message
...
>>
>> 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.
>
>I think you may be confusing a CO2 extinguisher with a dry chemical
>extinguisher. A CO2 extinguisher has no by-product other than the moisture
>in the air which may be frozen by the expanding CO2. A dry chemical
>extinguisher may leave corrosive residue.
>
>You say that you are required to carry an extinguisher. I assume that the
>regulation specifies the minimum rating of the extinguisher - if not the
>agent. If the rating is specified and 1211 Halon is not available (try a
>marine store), I would get a dry chemical extinguisher of the minimum rating
>and carry it. Whether you use it or not will be apparent when the time comes
>and you will easily be able to choose between corrosion and the effects of
>the fire.
>
>With my wooden airplane, I carry a small 1211 Extinguisher which I bought at
>a garage sale. If the airplane catches fire, and there is dirt nearby, I
>will toss the extinguisher into the fire and make tracks in the dirt. :)
>
>Rich S.
>
Portable Halon extinguishers made before 1995 are legal for use.
Aircraft are still allowed to use Halon.
It is illegal to release holon into the environment except for use in
"emergency" fires (ie it is illegal to use for "training" purposes)

[Rich S.]

> wrote in message
...

> Portable Halon extinguishers made before 1995 are legal for use.
> Aircraft are still allowed to use Halon.
> It is illegal to release holon into the environment except for use in
> "emergency" fires (ie it is illegal to use for "training" purposes)

This, of course, varies with the country.

IMHO, Halon is not the ideal extinguishing agent for most aircraft fires,
especially in-flight. In order for Halon to be effective, it must be applied
to the fire before anything in the vicinity of the flammable gases becomes
heated to the ignition temperature of the gas, otherwise the fire will
re-ignite as soon as the concentration of the Halon drops below the
percentage needed to interfere with combustion.

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.

One needs to understand the process by which Halon inhibits fire. The fuel
(usually carbon-based material) has a greater affinity for the Halogens
(Chlorine, Fluorine, Bromine & Iodine) that it does for Oxygen. In the
presence of both Oxygen and a Halon, the fuel will "choose" to combine with
the Halon without the evolution of heat and light - what we call "Fire". If
sufficient Halon is available, all the fuel will combine with the Halon and
the fire will go out.

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.

Rich S.

[RV9]

>
> You say that you are required to carry an extinguisher. I assume that the
> regulation specifies the minimum rating of the extinguisher - if not the
> agent.

Haven't found the regulation pertaining to the quantity, though 2 lbs. seems
the norm. If anyone has the specific information, that would be appreciated.

[RV9]

> When one comes up on ebay.

As long as I would fly in Canada, that would be fine. One border crossing
could get me in trouble (see my references).

[Rich S.]

"RV9" > wrote in message
...
> >
>> You say that you are required to carry an extinguisher. I assume that the
>> regulation specifies the minimum rating of the extinguisher - if not the
>> agent.
>
> Haven't found the regulation pertaining to the quantity, though 2 lbs.
> seems
> the norm. If anyone has the specific information, that would be
> appreciated.

The regs probably specify a numerical rating rather than a weight. In
addition to the number, there should be some letter(s) which rate the
extinguisher for the type of fire. A = Ordinary combustibles, B = Flammable
liquids, C = Suitability for fires involving electricity, D = Flammable
metals, etc. I must admit that I have been out of the fire business for
twenty years and much of my knowledge is out-of-date, especially where
regulations are concerned.

Here's an explanation of an extinguisher's rating taken from the NFPA
question and answer page:

I have a dry chemical fire extinguisher rated 2-A:10-B:C. What does that
rating mean?
Extinguishers achieve their ratings by putting out fires in laboratory
settings. The fire test standard is UL711, Standard for Rating and Fire
Testing of Fire Extinguishers. For the 2-A rating, 78 pieces of trade-sized
2-by-2-by-255/8 inch (5-by-5-by-66 centimeter) spruce or fir are placed in
a wood crib in 13 layers, then ignited and allowed to burn for 10 minutes.
Another fire test uses a vertical wood panel with 10-by-10-foot
(3-by-3-meter) furring strips. A third traditional fire test using excelsior
may be eliminated. The 10-B test involves a 25-square-foot
(2.3-square-meter) pan of heptane. The C rating doesn't involve fire, but
requires that the extinguishing agent not conduct electricity when
discharging across a 10-inch (25-centimeter) air gap between a grounded
plate and a potential of 100,000 volts AC. If the fires are extinguished
during the tests, the extinguisher gets the rating.

Rich S.

[[email protected]]

The references mention importing the fire extinguisher.
Are you importing anything if you fly home to Canada
from the US if you only have what you left Canada with.

ie are you importing your RV.

Just a thought

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


Jim Pollard
ch601hds
ea81

[Lakeview Bill]

I don't generally hang on to posts unless they are of special interest, but
this topic seems to be getting batted about far longer than necessary, so
please excuse my hanging this response off your post...

From a quick Google, it appears that Canada operates under the same rules as
does the US, which permit the use of Halon fire extinguishers in aircraft.

I think that a quick check of the CAA regulations, or a phone call or email
to these folks:

http://www.h3r.com/

might readily resolve the situation...





> wrote in message
oups.com...
> The references mention importing the fire extinguisher.
> Are you importing anything if you fly home to Canada
> from the US if you only have what you left Canada with.
>
> ie are you importing your RV.
>
> Just a thought
>
> the guy on ebay that has them once in a while is
> called firebruiser from Oshawa That is where I got
> mine.
>
>
> Jim Pollard
> ch601hds
> ea81
>

[RV9]

> 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.

[Drew Dalgleish]

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

http://www.tc.gc.ca/aviation/applications/exemptions/docs/en/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 Sapphire:
>http://www.tyco.com/tyco/press_release_detail.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.
>
>
>
>----------------------------------------------------------------------------
>-------------------
>References:
>
>
>
>http://www.cbsa-asfc.gc.ca/E/pub/cm/d19-7-2/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/commerce/circulars/AC0179.htm
>
>"to date none of these agents have been approved as a substitute for Halon
>hand-held fire extinguishers used on board aircraft."
>
>
>

[Ron Natalie]

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.

[Cy Galley]

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.

[Rich S.]

"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/elwood89/temp/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.

[[email protected]]

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

[Rich S.]

> 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.

[[email protected]]

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

[Rich S.]

> 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.

[Teamfcar]

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

[Drew Dalgleish]

>>
>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

A triple F is wonderful stuff. I've trained with it for fighting
underground mine fires. Since it's mostly water an extinguisher big
enough to do any good would be very heavy. probably not the best
choice for an on board extinguisher.

[Teamfcar]

Drew Dalgleish wrote:
>
> A triple F is wonderful stuff. I've trained with it for fighting
> underground mine fires. Since it's mostly water an extinguisher big
> enough to do any good would be very heavy. probably not the best
> choice for an on board extinguisher.

From what I can tell in the auto racing catalogs (Pegasus for one,
http://s2.pegasusautoracing.com/026.pdf), there are systems from 2 to 4
liters weighing about 7 and 16 lbs respectively. These are being
marketed as direct replacements for the 5 and 10lb Halon systems. I
realize it is much easier to get out of a burning race car even if it is
doing 160 mph or better than almost any airplane but the systems look
interesting. Most open wheel cars I used to run use the 5lb Halon
systems to meet the SCCA rules. Even with the larger 4L system it seems
to me the 16 or so pounds might buy some very valuable time in an airplane.

Mike Butler

[Rich S.]

"Drew Dalgleish" > wrote in message
...
>
>>>
>>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
>
> A triple F is wonderful stuff. I've trained with it for fighting
> underground mine fires. Since it's mostly water an extinguisher big
> enough to do any good would be very heavy. probably not the best
> choice for an on board extinguisher.

You are right on, Drew! That stuff rocks. I couldn't think of the term right
away. When a bunch of us let a drill fire get away down at Boeing Field one
time, we fought it with a couple of 2-1/2 lines for about twenty minutes.
When it became apparent we were over our head, Boeing's Attack rig hit it
with a ten-second burst of AFFF. It went out, NOW. The driver leaned out the
door with his hanky and wiped the last drip or two off the nozzle.

Man, that takes me back. . .

Rich S.

P.S. It's Aqueous Film Forming Foams.

[Corky Scott]

On Tue, 19 Jul 2005 15:11:53 GMT, "Cy Galley" >
wrote:

>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.

I remember a "discovery" or "military weapons" show I watched one time
where they were attempting to find a substitute for the Halon based
fire extinguishing system being used on some military jet.

They demonstrated the ability of the Halon system to put out a fire
created by a 20mm cannon hit, under controlled conditions. The
conditions included being in a wind tunnel, or directing high speed
air onto the area to be hit to simulate relatively high speed flight.

The Halon based system did a pretty good job of snuffing the fire out
from the cannon shell hit, even while the flame was being fanned by
the high speed air. Must have been a lot of Halon, I guess.

None of the other types of systems shown seemed to work quite so well.

This all came to be because Halon is a CFC, as is the refrigerant
R-12. They are both similar inert gasses. I recall a demonstration
one time wherein this guy breathed in from a hose of R-12, and then
breathed out over a lit candle. The R-12 settled over the flame and
extinguished it.

As a mechanic back in the 70's, we used to discharge that stuff all
over the place. It didn't matter we were told, it was an inert gas...

Corky Scott

[RV9]

Thanks for the feedback to all.

We're now off to Oshkosh, with a detour over northern NY, then off to
Oshkosh via Chicago.

Cheers.

Airventure ... the world's biggest aviation toy store :-)

[[email protected]]

Corky Scott wrote:
>
>
> This all came to be because Halon is a CFC, as is the refrigerant
> R-12. They are both similar inert gasses.

They ARE very stable, but not 'inert gasses'.

Historically 'inert gasses' were a handful of chemical elements,
that in their natural state at room temperature were monatomic
gasses, and which would not form any chemical compounds under
any conditions.

Sometime after the mid 20th century some shortlived compounds of
Neon (and maybe some others) were formed under laboratory conditions.
Consequently, the proper term for these gasses was changed to
'noble' gasses, meaning the were reluctant to combine with other
elements, but not completely inert.

AFAIK 'inert gas' remains as an archaic term synominous with
'noble gas'.

> ... It didn't matter we were told, it was an inert gas...
>

I think welders use the term 'inert gas' for any gas that will
not ready with the metal they are welding by whatever technique
they are using. But CFCs/Freons never qualified as 'inert'
even by that defintion.

Oh well, such is the nature of slang.

I remember the screens used to support a beaker over a bunsen
burner. they had a disc of asbestos in the middle so the flame
would not burn through the wire. Bet those were a great source of
airborne asbestos fibers.

--

FF

[Corky Scott]

On 20 Jul 2005 10:43:08 -0700, wrote:

>They ARE very stable, but not 'inert gasses'.

I stand corrected, the guy demo'd how to service automotive A/C
systems, I doubt he was a trained chemist. I for sure didn't know
enough chemistry to challenge, or even know the difference. ;-)

I was just impressed that anyone would inhale the stuff.

Corky Scott

[Morgans]

"Teamfcar" > wrote

> Even with the larger 4L system it seems
> to me the 16 or so pounds might buy some very valuable time in an
> airplane.

Where would you chose to have the system protecting, the cockpit or under
the cowl, and why?
--
Jim in NC

[Teamfcar]

Morgans wrote:
> "Teamfcar" > wrote
>
>
>>Even with the larger 4L system it seems
>>to me the 16 or so pounds might buy some very valuable time in an
>>airplane.
>
>
> Where would you chose to have the system protecting, the cockpit or under
> the cowl, and why?

I cannot make a qualified answer for aircraft, but the SCCA requires one
nozzle for the engine bay and another for the Driver in the cockpit. A
5 lb Halon will go for 30 or 40 seconds from two nozzles In the engine
bay we usually aimed it at the carburetors (Dual Webers side drafts or
Fuel Injection) such that it would end up down on the oil pumps. As it
was explained to me the two most flammable things in the engine are the
fuel and the oil. In the cockpit it was right behind the dash aimed
down and back to cover the drivers legs and flow back up his torso. In
most cases in open wheel racing, the fuel cell either forms the back of
the seat or is nested to the back of the drivers seat. So that would be
the most likely source to feed any flames in the cockpit. In an
aircraft I would probably use the same ideas to allow the prevailing air
stream carry the AFFF or Halon to the likely site of the flames.

Mike Butler

[[email protected]]

Corky Scott wrote:

> ...
>
> I was just impressed that anyone would inhale the stuff.
>

I'm impressed also, and not favorably. Although CFC refrigerant
itself is non-toxic, like air from a shop compressor it usually
contains trace contamination by lubricants making it dangerous
to inhale.

Ditto for helium sold to inflate balloons. Sure, you can make
your voice sound funny but you can get chemical pnemonia too.

--

FF

[Ron Natalie]

> 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?

No. Race cars are one thing. You expect to be able to get out of
them quickly. Aircraft are confined spaces that you need to habitate
in for maybe another ten minutes or so to land the thing.

[Teamfcar]

Ron Natalie wrote:

>
>> 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?
>
>
> No. Race cars are one thing. You expect to be able to get out of
> them quickly. Aircraft are confined spaces that you need to habitate
> in for maybe another ten minutes or so to land the thing.

True, but you pilot types tend to keep the fuel out of the compartment
you sit in. In our case the order of "flight" is, Driver/Fuel/Engine
with not much more space between them than it took to type it. The
differences between racing and flying are many but it is still possible
to learn from each other.

This has been quite informative for me anyway, thanks to all.

Mike Butler