Long Beach hangar gets slimed. Copter destroyed?

[mikea]

"It might as well have fallen into the ocean.."

With video:

Thousands of gallons of firefighting foam were accidentally released Thursday in a Long Beach airport hangar, covering a police helicopter and other vehicles with fizzy bubbles.

http://www.latimes.com/news/local/crime/la-me-foam12-2008dec12,0,2269594.story

I wanna know why the news copter pilot thinks the helicopter is destroyed.

I once was chatting away with a guy who was servicing the Halon (now isobutane(?) isopropolene(?)) system in the data center. He got real quiet and annoyed as he got near the system. I figured out it was like approaching the detonator on the explosives and he didn't need some geek asking him questions, like what is isopropolene.

BTW, I was an alarm guy but I only had to deal with water sprinkler systems. You could screw those up on a bad day, too, but the worst would be having to take apart huge pipes to fish out a paddle.

 

[poadeleted20]

One of the more popular replacements for 1301 dump systems is HFC-227 (heptafluoropropane). I'm not aware of any butane-series substances for that purpose (probably too heavy to be a good volume-fill gaseous agent at STP), although isobutane is used as a CFC propellant replacement.

 

[Skip Miller]

Not the first time it has happened....

-Skip

 

[KennyFlys]

Not the first time it has happened....

-Skip

Wasn't that the one where the system was set off by the kid of an event attendee?

 

[Steve]

The military has their own version...

http://www.strategypage.com/military_photos/20064611181.aspx

 

[Henning]

"It might as well have fallen into the ocean.."

With video:



I wanna know why the news copter pilot thinks the helicopter is destroyed.

AFFF gets into everything and is somewhat corrosive. It's going to be a major project to get it cleaned out properly and flying again.

 

[Cap'n Jack]

I once was chatting away with a guy who was servicing the Halon (now isobutane(?) isopropolene(?)) system in the data center. He got real quiet and annoyed as he got near the system. I figured out it was like approaching the detonator on the explosives and he didn't need some geek asking him questions, like what is isopropolene.

One of the more popular replacements for 1301 dump systems is HFC-227 (heptafluoropropane). I'm not aware of any butane-series substances for that purpose (probably too heavy to be a good volume-fill gaseous agent at STP), although isobutane is used as a CFC propellant replacement.

I'm pretty sure that isobutane (or other non-substituted hydrocarbons) aren't used in a fire fighting system. It would be like putting out a fire by throwing gasoline on it.

It is of academic interest what they use for a blowing agent.

 

[Teller1900]

We use Halon in our engine/baggage fire bottles, and also a couple of the extinguishers in the cabin/cockpit. That stuff is nasty!

A while back a mechanic accidentally blew a Halon bottle into an engine while trying to replace a light bulb. The easiest fix they could find...drive a new engine from Albany, NY to Lebanon, NH and hang it on the airplane as it sat on the ramp. Plane was down for a week and a half; it took them almost a month to get all the turbine disks and stator vanes cleaned well enough to run the engine again.

We have to practice with the halon extinguishers once every year (or two?) About six months before I was hired, a class was using Halon when one guy accidentally caught a small breath of the stuff caught in the breeze...knocked him out almost instantly.

As to the OP...seems like good practice for the snow plow drivers!

 

[Henning]

We use Halon in our engine/baggage fire bottles, and also a couple of the extinguishers in the cabin/cockpit. That stuff is nasty!

A while back a mechanic accidentally blew a Halon bottle into an engine while trying to replace a light bulb. The easiest fix they could find...drive a new engine from Albany, NY to Lebanon, NH and hang it on the airplane as it sat on the ramp. Plane was down for a week and a half; it took them almost a month to get all the turbine disks and stator vanes cleaned well enough to run the engine again.

We have to practice with the halon extinguishers once every year (or two?) About six months before I was hired, a class was using Halon when one guy accidentally caught a small breath of the stuff caught in the breeze...knocked him out almost instantly.

As to the OP...seems like good practice for the snow plow drivers!

That wasn't Halon, halon is a clear gas related to Freon in air conditioning (a chloroflurocarbon). Back in the day, they used to do a demo with Halon at trade shows. They had a guy stand in a glass blox, pull out a cigarette and light it with a zippo and stand there with the lighter lit and smokeing, and they'd blow in the Halon and the cigarette would go out as well as the lighter but the dude was fine.... He died a few years ago from cancer....

What you saw go off was a Dry Chem fire extinguisher, and yeah, that stuff is a nightmare. If it would have been Halon, they would have just vented the engine and all would have been fine.

 

[malainse]

What you saw go off was a Dry Chem fire extinguisher, and yeah, that stuff is a nightmare. If it would have been Halon, they would have just vented the engine and all would have been fine.

Correct...

 

[Trapper John]

"It might as well have fallen into the ocean.."

With video:



I wanna know why the news copter pilot thinks the helicopter is destroyed.

I once was chatting away with a guy who was servicing the Halon (now isobutane(?) isopropolene(?)) system in the data center. He got real quiet and annoyed as he got near the system. I figured out it was like approaching the detonator on the explosives and he didn't need some geek asking him questions, like what is isopropolene.

BTW, I was an alarm guy but I only had to deal with water sprinkler systems. You could screw those up on bad day, too, but the worst would be having to take apart huge pipes to fish out a paddle.

I'm surprised that a non-military installation would have a foam-type fire suppression system in a hangar. As Henning pointed out, that's usually AFFF, with the corrosive downside, plus it's an extremely expensive system to install and maintain. Maybe LA county has more money than sense?


Trapper John

 

[Pilawt]

Maybe LA county has more money than sense?

Bingo. And these days they don't have much money.

 

[Ghery]

That wasn't Halon, halon is a clear gas related to Freon in air conditioning (a chloroflurocarbon). Back in the day, they used to do a demo with Halon at trade shows. They had a guy stand in a glass blox, pull out a cigarette and light it with a zippo and stand there with the lighter lit and smokeing, and they'd blow in the Halon and the cigarette would go out as well as the lighter but the dude was fine.... He died a few years ago from cancer....

What you saw go off was a Dry Chem fire extinguisher, and yeah, that stuff is a nightmare. If it would have been Halon, they would have just vented the engine and all would have been fine.

I remember seeing a similar demonstration back in the late 1970s when I worked for the Navy. Long play salesman, and we waited in vain for the Halon to put him out. He used candles at various levels in the box.

 

[KennyFlys]

That wasn't Halon, halon is a clear gas related to Freon in air conditioning (a chloroflurocarbon). Back in the day, they used to do a demo with Halon at trade shows. They had a guy stand in a glass blox, pull out a cigarette and light it with a zippo and stand there with the lighter lit and smokeing, and they'd blow in the Halon and the cigarette would go out as well as the lighter but the dude was fine.... He died a few years ago from cancer....

What you saw go off was a Dry Chem fire extinguisher, and yeah, that stuff is a nightmare. If it would have been Halon, they would have just vented the engine and all would have been fine.

I recall reading something a while back about Halon to be replaced because of its effect on the environment similar to Freon.

 

[mikea]

I recall reading something a while back about Halon to be replaced because of its effect on the environment similar to Freon.

Halon is, for the most part, banned. IIRC, you can only buy it for specific applications, like aircraft.

 

[Henning]

I recall reading something a while back about Halon to be replaced because of its effect on the environment similar to Freon.

That is correct as 1211 and 1301 Halon were Chlorofluorocarbons and have been banned under international treaties in all but a few uses, and are being replaced by modified gases (as are the Freon series of gases such as the R-134a in your car has replace R-12 of the past) that are less unfriendly to ozone (O3).

 

[Henning]

I'm surprised that a non-military installation would have a foam-type fire suppression system in a hangar. As Henning pointed out, that's usually AFFF, with the corrosive downside, plus it's an extremely expensive system to install and maintain. Maybe LA county has more money than sense?


Trapper John

In any building required a sprinkler system, AFFF is not a huge addition to the cost of the system, and in a situation such as an aircraft hangar where large amounts of fuel may be present, the reduction in the insurance premium (if not an out right requirement for insurance or local code) will offset the cost.

 

[Teller1900]

That is correct as 1211 and 1301 Halon were Chlorofluorocarbons and have been banned under international treaties in all but a few uses, and are being replaced by modified gases (as are the Freon series of gases such as the R-134a in your car has replace R-12 of the past) that are less unfriendly to ozone (O3).

From the CFM:

A fire extinguisher supply cylinder is mounted aft of the main spar in each wheel well. Each cylinder is charged with 2.10 pounds of bromotrifluoromethane (Halon) pressurized to 360psi at 70F.

I wasn't there for either of the incidents I mentioned in the previous post, they're both stories that have been told to me. All I know is what the book says (and the fact that the two hand held extinguishers in the cockpit/cabin say "HALON" on them in really big green letters.

 

[Henning]

From the CFM:



I wasn't there for either of the incidents I mentioned in the previous post, they're both stories that have been told to me. All I know is what the book says (and the fact that the two hand held extinguishers in the cockpit/cabin say "HALON" on them in really big green letters.

I'm sure the cockpit extinguishers and the fixed system are Halon, and I'll bet if there was a problem like the one you said, the guy had tripped a portable Dry Chem extinguisher they had at the work station. Halon 1301 is a clear and odorless gas, here's its MSDS Sheet.

BTW, if you ever have to discharge the Halon in the cockpit, put your O2 mask on first. While Halon in itself isn't immediately toxic or an asphyxiant, it's reaction with various burning synthetics releases Hydrofluoric gas and various cyanide compounds which can immediately incapacitate, cause long term damage or kill you outright.

 

[vontresc]

Yeah I think the recent Russian sub accident was due to the Halon (or similar) fire supression system tripped accidentally. The fatalities were mainly contractors not trained to don the emergency breathing apparatus IIRC.

HALON is pretty nasty. I remember getting the spiel on getting out of the computer room NOW if I ever heard the fire supression alarm go off.

 

[Teller1900]

I'm sure the cockpit extinguishers and the fixed system are Halon, and I'll bet if there was a problem like the one you said, the guy had tripped a portable Dry Chem extinguisher they had at the work station. Halon 1301 is a clear and odorless gas, here's its MSDS Sheet.

BTW, if you ever have to discharge the Halon in the cockpit, put your O2 mask on first. While Halon in itself isn't immediately toxic or an asphyxiant, it's reaction with various burning synthetics releases Hydrofluoric gas and various cyanide compounds which can immediately incapacitate, cause long term damage or kill you outright.

I wasn't doubting you, simply explaining the basis of my story that was apparently missing a few facts (imagine that from a hangar tale!)

Sounds like the Halon, while putting out a fire, could potentially do just as much harm as good. What are the benefits of Halon vs. Dry Chem vs. CO2? Specifically, why would aviation use Halon so widely if it can cause noxious and potentially fatal fumes on contact with burning stuff (presumably what it's going to be coming into contact with, if used)?

 

[Henning]

Yeah I think the recent Russian sub accident was due to the Halon (or similar) fire supression system tripped accidentally. The fatalities were mainly contractors not trained to don the emergency breathing apparatus IIRC.

HALON is pretty nasty. I remember getting the spiel on getting out of the computer room NOW if I ever heard the fire supression alarm go off.

Actually, Halon itself is not nasty, that's why it was such a good deal, it put out fires in confined spaces without endangering the person with the extinguisher (although the 1301 in fixed systems is a bit harsher on your lungs than the 1211 in hand portables). My engine room systems which used to be Halon are now back to CO2, and with that we are required an autometed 15 second delay rigged to a "clear the space" alarm system with lights and sirens because anyone in that space will be asphyxiated now and die regardless the extent of the fire. With Halon that wasn't the situation. It could go off "now" and stop fires much earlier. 15 seconds is a long time for a fire to grow in a pressurized fuel fed fire....

It's the byproducs of hydrocarbon polymer combustion in a flourine rich environment. When flourine is introduced to it at high temperatures, you end up with hydrofluoric acid in the atmosphere, not a particularly good thing. Depending on the compound burning, various other nifty toxins can be produced as well.

BTW, I'm not a chemist, this comes from my Firefighting and Hazwhopper training.

 

[t0r0nad0]

Actually, I thought that the foam system was pretty standard in most newer hangars. Here's one at IAH:

 

[Henning]

I wasn't doubting you, simply explaining the basis of my story that was apparently missing a few facts (imagine that from a hangar tale!)

Sounds like the Halon, while putting out a fire, could potentially do just as much harm as good. What are the benefits of Halon vs. Dry Chem vs. CO2? Specifically, why would aviation use Halon so widely if it can cause noxious and potentially fatal fumes on contact with burning stuff (presumably what it's going to be coming into contact with, if used)?

Read my last post for the practical difference between Halon and CO2
As for both of them, they are an clear odorless gas, although you see the condensation from a CO2. Halon works by breaking the chain reaction that allows the fire to oxidize rapidly. CO2 works by displacing oxygen so the fire "suffocates". In other words it displaces the oxygen required for rapid oxidation.

Dry chem forms a crust over the burning material and provides a barrier against the oxygen required for rapid oxidation.

Then there is Class D powder which provides the same function as ABC dry chem, but does it at the much higher temperatures of burning metal such as magnesium. Salt also works on class D metal fires, and whenever I'm machining on it, I always have a bucket of salt and a scoop next to me.

 

[vontresc]

Wile talking about fire supression system screwups, we had a pretty good one recently at work.

Apparently some electrical contractor was working with some wiring, and set off some old fire alarm system on our floor. Instead of calling up the fire contractor, they decided to bypass something to silence the alarm. BAD move. They ended up triggering the deluge supprression system (not the regular sprinklers though), and ended up flooding that wing with several thousand gallons of water from out standby tank on the roof. I don't know how long the water had been sitting up there, but by the time it camoe out of the system is smelled pretty rank (very sulfurus).

Best part this happened during the flooding in the upper midwest this spring. I'm guessing being an Insurance co helped in actually finding a flood cleanup contractor.