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Halon - Commission to propose remove aviation's critical use exemption

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Halon - Commission to propose remove aviation's critical use exemption

Old 6th Jun 2009, 16:29
  #41 (permalink)  
 
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Rainboe-you're entirely correct

I got a snootful of that stuff in a boat galley fire some years ago, and the first thought that went through my mind was I was gonna die from the halon.
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Old 6th Jun 2009, 20:11
  #42 (permalink)  
 
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halon gas effects

On the other hand, in KSA in the early 'eighties my colleague and I were subjected (inadvertently) to the effects of two 4ft x 18ins dia halon gas bottles being discharged into a computer room where we were conducting a fire detection/suppression system acceptance test. Due to a wiring problem/teflon tape error, the smoke detection-alarm condition turned into an unplanned discharge of the two halon tanks. Unlike helium gas which turns the human voice to Mickey Mouse qualities, the human voice under the effects of halon becomes like HAL9000 exaggerated and it is like being drunk. The false floor tiles lifted, floated and rippled accompanied by "Ha-Ha......Dave....why....did....you....do....that" giggle...giggle..giggle. The effects lasted for some seconds after exiting the room but, as far as I am aware, had no lasting impact (unless you talk to my wife !)
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Old 6th Jun 2009, 21:45
  #43 (permalink)  
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daved

Not really my field but Halon gases are admirable anaesthetics and the effects you describe fit that characteristic more or less exactly.

Try Halothane - Wikipedia, the free encyclopedia

CW
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Old 7th Jun 2009, 12:30
  #44 (permalink)  
 
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The toxicity of Halon is extremely low when applied in normal firefighting quantities and concentrations (as I understand it).

Agreed, when automated systems, such as in Flight Simulator buildings are flooded with copious and excessive quantities to cover the worst fire situation envisaged by the designers, then the threat to life due to decreased oxygen levels obviously increases unless you calmly walk outside the subject building, cancel the sim session and have a cup of coffee. You don't have this luxury in an aircraft fire.

I am a human being first and a pilot second. So I demand the very best solution when my aircraft catches fire and threatens the lives of my passengers and crew.

As far as I am aware, Halon has been proved as the very best extinguishing agent available to mankind at this point in the history of aviation (perhaps the one thing Boeing and Airbus agree upon?).

So if some deluded, or perhaps I should say more diplomatically, misguided soul, seeks to remove the most effective fire extinguishing agent known to mankind in preventing my passengers and crew from suffering a fiery death or the trauma of death from falling to earth from a great height in a structurally damaged aircraft, then I beg to disagree.

You want to get rid of Halon? Then, first of all, show me some agent that is at least as good if not better than Halon for extinguishing fires in aircraft. Then I will be all ears...
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Old 7th Jun 2009, 15:24
  #45 (permalink)  
 
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I'm with Rainboe and sb_sfo. Its gone from most other spaces: from my vantage point in the T5 lounge there are only two types: CO2 and AFFF (Aqueous Film Forming Foam in case you were interested - used to be made from Ox blood I believe. Or maybe our fire officer was pulling my leg.)

Our critical use exemption expires shortly for all except the offshore industry and that expires soon after afaik. We'll manage. Halon really is the pits.

Pinkman
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Old 7th Jun 2009, 18:22
  #46 (permalink)  
 
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Anyone know how much CO2 would be required as an ETOPS 180 suppressant in say a 330? given that with halon you need to keep 3% volume I guess with CO2 you would need 30% volume. That's a lot of extinguishant and a lot of fuel burn to carry it.
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Old 7th Jun 2009, 18:36
  #47 (permalink)  
 
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I know this halon is very toxic but in a few years of flying nor I or my colleagues ever used it. We know we have it there and that its very effective. Id rather be intoxicated with halon and treat my lungs than hving a fire out of control in the cabin cos we all know its over if that happens.

If they give me something else which is less harmig for the enviroment and does the same work Im happy. If not they 'd better think twice.

Someone said here to double the number of fire extinguishers (if they are changed with something less effective). You can put 100 of them but if the first one is not effective and you are wasting time using another two than you 're probably gone.
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Old 11th Jul 2009, 14:36
  #48 (permalink)  
 
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I know this halon is very toxic but in a few years of flying nor I or my colleagues ever used it. We know we have it there and that its very effective. Id rather be intoxicated with halon and treat my lungs than hving a fire out of control in the cabin cos we all know its over if that happens.
Actually the toxicity is said to be very low:
http://erd.dli.mt.gov/safetyhealth/brochures/halon.pdf
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Old 12th Jul 2009, 01:09
  #49 (permalink)  
 
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As self loading freight I have always been reassured by the presence of Halon extinguishers in the aircraft cabin. I have seen many demonstrations of fire extinguishers and given quite a few myself. Halon has always come out on top for ease of use and speed of knock down. For an aircraft cabin fire there is nothing to better a hand held Halon extinguisher.

There is a considerable difference in characteristics between fixed fire fighting systems and hand held extinguishers. For engine fires where there is fixed 'plumbing' there may be a suitable replacement...BUT please remember the papers posted previously on this site are by the manufacturers of the replacement extinguishing agents! Note also that some agents use Nitrogen as a propellant gas, OK, we breath it all the time at 78% concentration but it will suffocate at around 91%, not good for use in a cabin?

As far as dry powder extinguishers go, if you have not seen one discharged, or discharged one yourself then you are in for a treat! Visibility goes immediately and the white fog that ensues takes ages to settle as a fine white dust. This would be guaranteed to cause panic if used in the confines of an aircraft cabin.

IF, as mentioned in a previous post, extinguishing powder can damage metal (and presumably aircraft alloys are more reactive than most others) then one discharge could be a very serious problem to the airframe as the powder gets EVERYWHERE.

As far as 'Pinkman is concerned' - he can walk out of T5, I don't fancy walking out of an aircraft at 35,000ft when the 'EU suitable replacement' fails to check a small fire which halon would easily cope with.
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Old 15th Jul 2009, 23:37
  #50 (permalink)  
 
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Pinkman - Ox blood was utilised in protein foams - a cheaper and earlier type of extinguishant than the more modern AFFF.

Halon has low toxicity (unless exposed to flame at which point that proportion which contacts the heat source becomes highly toxic). I was subjected to exposure in many discharge tests and suffered no apparent side effects other than perhaps shrinking testicles which is how I ended up working for Ryanair....... I was in that industry for 12 years running my own company designing, installing and maintaining fixed systems. Its like will never be known again according to my sources......

FM200 is close but like the proverbial bridesmaid. Pyroshield or Argonite don't profess to compete as installations are so heavy as to be useless in this application (fixed systems) and I doubt that handheld units are available although I stand to be corrected as I have been safely removed from that industry now for some years.

To whoever it was who wondered how much CO2 it would take to be effective on an A330 - ditch the thought. I'm sure you aren't proposing to flood the fuselage and the suppression of an engine fire using CO2 is not an application any self respecting design engineer (or even salesman) would ever consider. I'm sure your comment was tongue in cheek.

I do hope that common sense prevails as our lives stand to depend on this agent.
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Old 16th Jul 2009, 09:27
  #51 (permalink)  
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Here's what's happening on the A350

Which will be non-halon in the engine and APU, halon in the cargo bay.
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Old 21st Jul 2009, 10:41
  #52 (permalink)  
 
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Halon - Commission to propose remove aviation's critical use exemption

FlexibleResponse wrote:

I am a human being first and a pilot second. So I demand the very best solution when my aircraft catches fire and threatens the lives of my passengers and crew.
Do you also insist on aft-facing pax seats, three-point harnesses, cabin water misting, smoke hoods, gelled kerosene and reticulated fuel tanks?

Halons are undoubtedly effective but are no longer in production. However airlines appear to believe that ignorance of the problem is the best option, presumably because it is the cheapest option in the short-term .

Even the ICAO recommends:

The aviation industry should be encouraged by regulators to follow the lead of other user communities which have had similar difficult problems to overcome...
( ICAO Journal Volume 60 Number 5 )

In spite of the looming problem, the only alternative now in regular commercial use is used for lavatory waste basket fire suppression in the A340-500 / 600.

So why all the blood-curdling cries against the EC?
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Old 30th Jul 2009, 13:57
  #53 (permalink)  
 
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Re dry powder extinguishers

Something not mentioned in the comments about dry extinguishers:
The powder is corrosive in the presence of moisture - goodbye electronics (experienced it myself at great expense to my employer) so not an option.
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