Fire extinguisher placement

G

Goodyear

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Do you carry a fire extinguisher in the cockpit where you can reach it while flying? Where do you place it? I don’t really like using the tube next to the passengers head.
 
I'm also in the process of considering it. I'm thinking perhaps a small extinguisher like the PRT RT A400 (8.5"x2"). I'm also thinking I could secure the bracket to the rear lower seat tube using a pair of DG clamps. However, I need to check to see if I could actually reach it.
 
enough halon in an enclosed space and you'll be lights out pretty quickly. is there any route to a piped system to put the halon under the panel or around the engine?
 
Bartman said:
enough halon in an enclosed space and you'll be lights out pretty quickly. is there any route to a piped system to put the halon under the panel or around the engine?
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You should read AC 20-80, In-Flight Fires as well as AC 20-42D Hand Fire Extinguishers for use in Aircraft.

The short version is that while there are minimum safe limits for Halon exposure, and that high levels will cause dizziness, impaired coordination, and reduced mental sharpness, incapacitation due to Halon removing all the oxygen from the air is a myth. (We'll get into cabin volume and ventilation at the end.

Halon works by interfering with the chemical reactions that occur in a fire. The short and simple version is that it introduces non-reactive elements into the fire that reduce the reaction rate of the chemical reactions taking place and reduce the heat. It doesn't remove the oxygen, it just bonds with it at the point of the fire under high temperature conditions.

It might be worth considering the alternatives and how they work as well:

1) Water-glycol extinguishers work by reducing the heat of the fire to essentially eliminate the heat that is creating an ignition source. They also have a secondary function of the mist in the discharge reducing available oxygen. However, they are a non starter for most electrical fires (lithium battery fires being a notable exception) and can spread a fuel fire.

2) Dry powder extinguishers use a chemical like monoammonium phosphate, sodium bicarbonate, or potassium bicarbonate. Dry powders melt and in the process absorb heat, reducing the heat of the fire, and the melted powder then coats the burning material both preventing the release of toxic vapors and blocking oxygen. The downside is that you end up with very small particles get everywhere and are almost impossible to clean. In an aircraft cockpit fire, the instruments will pretty well be toast.

3) Foam extinguishers work by coating the burning material, and for a fuel fire will coat the surface and block oxygen. Given the water content of the foam, they are also very effective at reducing the heat of the fire.

4) CO2 extinguishers work in two ways. First is blocks oxygen and second when it makes a phase change from a liquid state (kept that way under pressure in the extinguisher to a gaseous state it absorbs a LOT of heat. It leaves no mess or residue to clean up, however CO2 toxicity is a big deal.

5) Halocarbon extinguishers are Halon replacements and work the same way, but weigh about twice as much for comparable effectiveness.

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That more or less leaves Halon as the go to choice in a small aircraft, with Halocarbon agents as the second choice - at twice the weight, with the same minimum safe volume issues and symptoms.

The minimum safe cabin volume for a full release of a 2.5 pound Halon extinguishers (a 5 BC rating) is 558 cu ft at sea level and 751 cu ft at 8,000 ft. A Citabria or Decathlon cabin probably has a volume of around 80 to 100 cu ft, that limits the safe weight of Halon to about .35 to .45 pounds at sea level. The bad news is that the PRT RT 400 is the smallest Halon extinguisher I can find and it has .9 pounds of Halon in it.

However, having .9 pounds doesn't mean I'll use all of it. If I am using all of it, it's because I'm probably on fire and the dizziness, lack of coordination and mental sharpness side effects of excess exposure are A LOT BETTER than being on fire.

Maybe more importantly I have this really big window that opens on the left and a jettisonable door on the right, so I have a huge amount of readily available cabin ventilation, in addition to the two vents under the panel. I'm not flying a pressurized aircraft and exposure to Halon really is the least of my concerns in a 7KCAB. What I do have is 18 gallons of 100LL on each side of me at head level and 1.5 gallons of 100LL in a header tank under the panel. I'm far more concerned with putting the fire out as quickly as possible.

Since the Halon reduces the rate of the chemical reactions taking place in the fire and rapidly reduces the heat, my main concern other than putting Halon on the fire is to shut off the master switch to remove the ignition source that might otherwise re-start the fire if it was an electrical fire and shut off the fuel to reduce the fuel if it's a fuel fire being fed by a broken line forward of the fuel shut off.
 
Yow! I am going to try to not catch on fire! I fly low enough that I will be on the ground by the time I could figure out an extinguisher. Good info, though.
 
Yes, good post @BB57 but it's complicated and just blasting a fire extinguisher isn't guaranteed to make the bad situation any better. Not saying it's a bad idea to install it but with it there has to be a plan for when it's needed and what the follow up to discharging it will be. Opening a door and window could clear the halon but reignite the fire, not an expert on every detail of it but just blasting a fire extinguisher and delaying other prudent actions might not be a best case scenario. I like the idea of having it available though. Anybody work out what their "Cockpit Fire" emergency checklist might look like? I don't recall if the POH specifically addresses this.
 
I think you want it in a location that you could get to when standing outside the door if a fire started on takeoff or you got back on the ground quick and out of the plane (#1 goal).
I definitely need to re learn the different fire responses.
 
FAA wants written checklists. I forget exactly what mine says, but it is something like Fuel - OFF, Master - OFF, Emergency Descent - INITIATE.

I teach to do all that simultaneously by memory, then take that shaky finger amd point to the checklist, and recite simply "Inflight Fire Checklist - COMPLETE"

Need one more item if extinguisher is on board.
 
There it is.
 

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As Richard Pryor used to say, "people get out of your way when you're on fire".

Goodyear said:
I have the halon 1.25 lb which is 10” by 3.6”
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I have this same unit, on the floor left side ahead of the front seat. The mount will absolutely take +5G and probably -5G but I won't be testing that.

Dry chem is out. You'll be blind and still can't breathe.

My employer is replacing on board halon systems with a newer type that is quite toxic for humans but better for the environment. Still scratching my head on that one.
 
NTSB accident report of an 8KCAB. Yikes!

The pilot reported that, after the airplane lifted off after several touch-and-go landings, he suddenly smelled fuel and observed streaming fuel. The fuel appeared to come from the fuel system header tank area and streamed onto the cockpit floor between his feet. He landed the airplane straight ahead and taxied clear of the active runway. The airplane caught fire, and the pilot exited through the cockpit door. Within a minute, the airplane was engulfed in flames. Airport rescue personnel responded and extinguished the fire. Post accident examination of the airplane revealed that almost all of the fuel lines going to or coming from the header tank were completely burned away. Two sections of fuel and vent lines remained attached to the header tank and were examined; no evidence of pre-existing fatigue or cracking was observed. According to the pilot, who was also the owner, no recent maintenance had been performed in the area of the header tank. It is likely that a sudden leak occurred at a line to or from the header tank; however, the fire destroyed all evidence of its origin.
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Having that header tank hanging over my balls always made me nervous. I'm going to add the fittings and hoses to my preflight.

Wearing long pants and leather shoes may buy you a little time.
 
I've seen a number of vehicle fires in my time. Two minutes is fully engulfed stage.
On my first annual the IA found the fuel line that goes through the firewall just plain line through a hole. I know the guys who did the annuals for years on this plane and none of them found it. It was rubbing and it was only a matter of time. Now it's a proper firewall fitting with a line on each side of the firewall.
Same IA noticed that the fuel valve shuts off after the primer line, so a primer system failure can not be remedied by shutting off the fuel.
A design flaw to be sure.
 
aftCG said:
I've seen a number of vehicle fires in my time. Two minutes is fully engulfed stage.
On my first annual the IA found the fuel line that goes through the firewall just plain line through a hole. I know the guys who did the annuals for years on this plane and none of them found it. It was rubbing and it was only a matter of time. Now it's a proper firewall fitting with a line on each side of the firewall.
Same IA noticed that the fuel valve shuts off after the primer line, so a primer system failure can not be remedied by shutting off the fuel.
A design flaw to be sure.
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I over-paid recently for a pre-buy, but stories like this make me glad I did.
 
Bartman said:
Yes, good post @BB57 but it's complicated and just blasting a fire extinguisher isn't guaranteed to make the bad situation any better. Not saying it's a bad idea to install it but with it there has to be a plan for when it's needed and what the follow up to discharging it will be. Opening a door and window could clear the halon but reignite the fire, not an expert on every detail of it but just blasting a fire extinguisher and delaying other prudent actions might not be a best case scenario. I like the idea of having it available though. Anybody work out what their "Cockpit Fire" emergency checklist might look like? I don't recall if the POH specifically addresses this.
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I agree Bart. I touched on that with my mention of master fuel and switch, but the issue I responded to was the concern about the effects of halon if you used a halon extinguisher.

Bob is also right on the money that the FAA has become a bit too checklist happy, wanting us all to fly a Champ or Citabria like a 757. He's also right on point that for the short emergency/immediate action items you memorize them and then just do it and point at the checklist when it's done.

I am not for example going to dig my checklist out of the pocket and then flip it over and search for the "in flight fire section and call out each item and then perform the action. I'm going to cut off the fuel, turn off the master, initiate the descent and put out the fire. Whether "put out the fire" comes last, first or somewhere in between will depend on what's feeding it and whether I am personally on fire or not.
 
Big Ed said:
NTSB accident report of an 8KCAB. Yikes!



Having that header tank hanging over my balls always made me nervous. I'm going to add the fittings and hoses to my preflight.

Wearing long pants and leather shoes may buy you a little time.
Click to expand...
My 7KCAB has a recently installed header tank the previous owner installed due to it deciding to start leaking.

When I got it home and had my mechanic look at it, he found the same issue as aftCG's mechanic - a fuel line running through the firewall with no fitting, no grommet, and not even any fireseal. There were in fact three other holes in the firewall with no grommets or fire seal. Most of those holes were also in the area of the header tank.
 
Check your fuel shut off. Mine was frozen open because nobody ever shuts their fuel off. No big deal to fix, but a bummer if it won’t move when you need it.
 
BB57 said:
................................ Whether "put out the fire" comes last, first or somewhere in between will depend on what's feeding it and whether I am personally on fire or not.
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Can't argue with that!

is "fire seal" the orange caulk type stuff?
 
Bartman said:
Can't argue with that!

is "fire seal" the orange caulk type stuff?
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My mechanic isn't a fan of the orange stuff and he had me use 3M Fire barrier 2000+ It's light gray and costs about $38 per 10 oz tube. Spendy but it works well, is easy to apply, sets up fast and stays flexible.
 
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