Fire Extinguisher
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Fire Extinguisher
Hi Folks,
Just a quick question with regards to fire extinguishers for ground (hangar) use. Presumably the extinguisher would be used in event of engine or avgas fire. What type would you recommend?
Water type is (I suspect) not the best for fuel fires, leaving CO2, foam or dry chemical powder as the other options. (Halotron too expensive)
I know the disadvantages of using CO2/dry powder in the air (toxic in enclosed cockpit/damaging to electronics), but for, say, an engine or fuel fire - would either work as well?
Many thanks,
qff
Just a quick question with regards to fire extinguishers for ground (hangar) use. Presumably the extinguisher would be used in event of engine or avgas fire. What type would you recommend?
Water type is (I suspect) not the best for fuel fires, leaving CO2, foam or dry chemical powder as the other options. (Halotron too expensive)
I know the disadvantages of using CO2/dry powder in the air (toxic in enclosed cockpit/damaging to electronics), but for, say, an engine or fuel fire - would either work as well?
Many thanks,
qff
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Not sure if its any help to you, but the hazchem code for avaition is fuel 3YE, the 3 means foam. So foam is the minimum allowed.
Most refueller trucks will have dry powder extinguishers on board.
Most refueller trucks will have dry powder extinguishers on board.
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QFF,
My two pence worth from the perspective of a firefighter (and aircraft mechanic)...
Your first concern when extinguishing a fire is your own safety. Secondary concerns include putting the fire out (a close second) and not making it worse, and finally your last concern (but an important one when planning ahead for a fire) is preservation of whatever is burning or in proximity to what's being burned. In short...your life and safety, other lives and their safety, and finally last, property.
Different extinguishing agents for different fires. Water is fine for Class A combustibles, such as paper and wood. If you're in a wooden hangar and the hangar is on fire, then water (ideally foam) is a good choice for direct application on the wood, only. However, if you've got a fire which has spread to petrochemicals such as fuel and oil or hydraulic fluid, then application of water can cause an explosion and spread the fire. If you're using a water extinguisher, also be aware that most of them contain anti-freeze agents in the form of glycol, which is toxic in it's own rite, and even more so in the presence of flame. If you're fighting the fire without breathing apparatus, the toxicity of the combustion byproducts (smoke, vapor, etc) is greater and and increases your own risk.
Water extinguishers are generally found for interior use in airplanes in the cabin; burning seat cushions and that type of material. Water won't do you any good on an electrical fire, obviously. Even if the fire isn't electrical in nature, if it's in proximity to live wires, breaker panels, busses, etc, then it also places you at risk. Placing water on the electrical equipment may cause a short and also contribute to a fire.
C02 is a good agent for electrical fires, and works well on small fuel fires. It's use is fairly straight forward. You've been taught about the fire triangle, with fuel, heat, and oxygen; it's both cooling the fire, and displacing oxygen. It works through two mediums to control the fire. If you're in the same environment, you do face the same problem as the fire, however, which affects you in the same way as the fire when it comes to getting oxygen. Unless you're in an enclosed space, this is seldom a problem, and your concern is usually getting rid of the fire (as it presents the greater hazard. CO2 may not have enough capability to put out a Class A fire (wood, paper, seat cushions, etc) of any significance unless it's in an enclosed area. If you're fighting an electrical fire and you don't get the electricity shut off once the flame goes out, CO2 won't prevent it from re-igniting, either.
Dry chemicals work too. As you noted, these can result in damage to equipment. If you're planning ahead, the use of halogen or CO2 is preferrable, but it's usually more expensive. DC extinguishers are less expensive, easy to maintain, easy to service, and fairly versatile. You need to have an idea what type of fires you'll be fighting. DC extinguishers work on Class A combustibles and Class B (liquids, such as fuel), but aren't really effective on electrical fires. Cleanup after discharging a DC extinguisher is a bear, and you'll be tasting bicarbonate for three days after you press the discharge lever (trust me on that)...but it works well on realtively small fires. I've used them a number of times on engine fires in both aircraft and automobiles, as well as fuel spills and industrial hazmat fires. I've also used them on very small structural fires with success...though you need to bear in mind that a DC extinguisher is very directional and very limited, and doesn't do well on a vertical fire (one climbing a wall, for example, or an overhead fire). You also need to bear in mind in that a lot of fine powder will be in the air, affecting your breathing (it won't hurt you, but it tastes nasty, and it's hard to breathe), and getting in your eyes and mucus membranes).
Dry chemicals may or may not be suitable for Class A fires. When a fire is vertical or even horizontal and hot, the DC may not be able to adequately cover or smother the fire enough to control it. You can think of a DC extinguisher as the equivilent of throwing dirt on the fire...it's a dirt extinguisher with a little more advanced dirt, and you're using an extinguisher instead of a shovel. Put it on hot components such as an engine, however, and it bakes right on. Add a little water and you have a mess. It doesn't melt, but as said before, cleanup can be a real bear.
Halogenated compounds such as Halon 1211 work differently than other agents. Where water cools the fire and in some cases removes oxygen (in a flooded situation, when used on product fires that aren't self-oxidizing), and C02 does both...halogens work using the fire tetrahedron. This is the traditional fire triangle with one more side: a chain reaction. Fire is a chemical process called pyrolosis. A compound or material is changing into another form while releasing heat energy. In some cases there's also a chemical chain reaction, and that's where halogen comes in. It's purpose is to interrupt the chain reaction. It's use is appropriate for Class A, B, and C fires, but it suffers from similiar limitations as C02 in that you may or may not have enough available if the fire is of any significant size. It's most effective in enclosed spaces, but again, just like CO2, it's also effective on YOU in enclosed spaces.
Halon is also referred to as Freon in various forms, and a recent incident on board an Akula-class Russian submarine involving release of the freon firefighting system (20 dead) points to the possible results if you use these compounds in a non-ventillated space. You should also be aware that Halon in the presence of flame can produce extremely toxic byproducts, including phosgene gas. Numerous toxic acids and byproducts come off smoke and the combustion process anyway...none of them are good for you and most are fatal in a short period of time with continued exposure...with or without extinguishing agents. Generally the fire is the immediate concern, but don't forget your own safety. Far better to pull back and let it burn, than to die trying to put a fire out. Safety first. Things can be replaced. If others are involved, remember that you should do what you can, but if you charge into a situation to rescue someone else and then become incapacitated, you've helped no one, and now you place other rescuers at risk by increasing their workload.
Another class of extinguisher and agent that you probably won't work with, but which is commonly found around aircraft, is Class D. It's for metal fires, such as a magnesium brake or engine fire. These fires are extremely dangerous, extremely hot, and very unstable. Putting the wrong agent on these can increase the fire tremendously, and frequently results in an explosion. A brake fire, for example, can explode violently if sprayed with water. A hot brake may require cooling rapidly (which will destroy the brake, incidentally)...but a metal fire, usually bright enough you can't look at it, will explode if water or other agents are applied.
Specific Class D agents such as Purple K need to be applied properly, and using the proper application and protective equipment...it's a situation when you want to be far away. Reflective suits, specialized breathing equipment, etc, is required.
A good rule of thumb when facing a hazardous materials fire...and there's very little in the hangar or around airplanes that doesn't constitute HazMat, is the thumb-rule: you need to be far enough away that you can hold your fist at arms length extend your thumb, and completely cover the scene from your view. If you're closer than that, you're too close. A good rule of thumb, using a real thumb.
From my perspective as a pilot, having had to discharge extinguishes in the airplane and outside the airplane several times, a DC extinguisher is probably the most messy, but probably the most versatile. It's what I carry in my car, and every year I put out one or two auto fires using a small 10 or 25 BC dry chemical extinguisher (in the USA, the 10 or 25 rating refers to the square footage, or area, expected to be extinguished by the fire extinguisher...the bigger the number, the bigger the extinguisher, and the greater the quantity of fire extinguishing agent).
If you have a chance to get with your local fire department for some hands-on training, it's usually best. It's worth the cost of an extinguisher to have a chance to put out a fuel fire, or extinguish different types of fires. Know what to expect, what to wear (synthetics are like wearing a match stick), and where to stand (upwind). Know how to approach the fire, who to call, when to run away, and how far to go (don't forget the rule of thumb).
If you have a backfire through your intake and end up with an induction fire, remember that the first source of fighting that fire is you...such that fire back into the engine. If it's not working, then don't hesitate to get someone else to discharge a C02, dry chemical, or halon extinguisher to put it out. Make sure you're not cranking the engine or propeller when they approach to do that. If it doesn't go out, don't hesitate to evacuate and abandon the airplane; no sense both of you burning up.
In flight...subject for a whole different discussion...I've had several of these and the most important thing I can tell you is DON'T PANIC. An inflight fire isn't necessarily the end of the world, but it surely could be if you panic.
Enough for now.
My two pence worth from the perspective of a firefighter (and aircraft mechanic)...
Your first concern when extinguishing a fire is your own safety. Secondary concerns include putting the fire out (a close second) and not making it worse, and finally your last concern (but an important one when planning ahead for a fire) is preservation of whatever is burning or in proximity to what's being burned. In short...your life and safety, other lives and their safety, and finally last, property.
Different extinguishing agents for different fires. Water is fine for Class A combustibles, such as paper and wood. If you're in a wooden hangar and the hangar is on fire, then water (ideally foam) is a good choice for direct application on the wood, only. However, if you've got a fire which has spread to petrochemicals such as fuel and oil or hydraulic fluid, then application of water can cause an explosion and spread the fire. If you're using a water extinguisher, also be aware that most of them contain anti-freeze agents in the form of glycol, which is toxic in it's own rite, and even more so in the presence of flame. If you're fighting the fire without breathing apparatus, the toxicity of the combustion byproducts (smoke, vapor, etc) is greater and and increases your own risk.
Water extinguishers are generally found for interior use in airplanes in the cabin; burning seat cushions and that type of material. Water won't do you any good on an electrical fire, obviously. Even if the fire isn't electrical in nature, if it's in proximity to live wires, breaker panels, busses, etc, then it also places you at risk. Placing water on the electrical equipment may cause a short and also contribute to a fire.
C02 is a good agent for electrical fires, and works well on small fuel fires. It's use is fairly straight forward. You've been taught about the fire triangle, with fuel, heat, and oxygen; it's both cooling the fire, and displacing oxygen. It works through two mediums to control the fire. If you're in the same environment, you do face the same problem as the fire, however, which affects you in the same way as the fire when it comes to getting oxygen. Unless you're in an enclosed space, this is seldom a problem, and your concern is usually getting rid of the fire (as it presents the greater hazard. CO2 may not have enough capability to put out a Class A fire (wood, paper, seat cushions, etc) of any significance unless it's in an enclosed area. If you're fighting an electrical fire and you don't get the electricity shut off once the flame goes out, CO2 won't prevent it from re-igniting, either.
Dry chemicals work too. As you noted, these can result in damage to equipment. If you're planning ahead, the use of halogen or CO2 is preferrable, but it's usually more expensive. DC extinguishers are less expensive, easy to maintain, easy to service, and fairly versatile. You need to have an idea what type of fires you'll be fighting. DC extinguishers work on Class A combustibles and Class B (liquids, such as fuel), but aren't really effective on electrical fires. Cleanup after discharging a DC extinguisher is a bear, and you'll be tasting bicarbonate for three days after you press the discharge lever (trust me on that)...but it works well on realtively small fires. I've used them a number of times on engine fires in both aircraft and automobiles, as well as fuel spills and industrial hazmat fires. I've also used them on very small structural fires with success...though you need to bear in mind that a DC extinguisher is very directional and very limited, and doesn't do well on a vertical fire (one climbing a wall, for example, or an overhead fire). You also need to bear in mind in that a lot of fine powder will be in the air, affecting your breathing (it won't hurt you, but it tastes nasty, and it's hard to breathe), and getting in your eyes and mucus membranes).
Dry chemicals may or may not be suitable for Class A fires. When a fire is vertical or even horizontal and hot, the DC may not be able to adequately cover or smother the fire enough to control it. You can think of a DC extinguisher as the equivilent of throwing dirt on the fire...it's a dirt extinguisher with a little more advanced dirt, and you're using an extinguisher instead of a shovel. Put it on hot components such as an engine, however, and it bakes right on. Add a little water and you have a mess. It doesn't melt, but as said before, cleanup can be a real bear.
Halogenated compounds such as Halon 1211 work differently than other agents. Where water cools the fire and in some cases removes oxygen (in a flooded situation, when used on product fires that aren't self-oxidizing), and C02 does both...halogens work using the fire tetrahedron. This is the traditional fire triangle with one more side: a chain reaction. Fire is a chemical process called pyrolosis. A compound or material is changing into another form while releasing heat energy. In some cases there's also a chemical chain reaction, and that's where halogen comes in. It's purpose is to interrupt the chain reaction. It's use is appropriate for Class A, B, and C fires, but it suffers from similiar limitations as C02 in that you may or may not have enough available if the fire is of any significant size. It's most effective in enclosed spaces, but again, just like CO2, it's also effective on YOU in enclosed spaces.
Halon is also referred to as Freon in various forms, and a recent incident on board an Akula-class Russian submarine involving release of the freon firefighting system (20 dead) points to the possible results if you use these compounds in a non-ventillated space. You should also be aware that Halon in the presence of flame can produce extremely toxic byproducts, including phosgene gas. Numerous toxic acids and byproducts come off smoke and the combustion process anyway...none of them are good for you and most are fatal in a short period of time with continued exposure...with or without extinguishing agents. Generally the fire is the immediate concern, but don't forget your own safety. Far better to pull back and let it burn, than to die trying to put a fire out. Safety first. Things can be replaced. If others are involved, remember that you should do what you can, but if you charge into a situation to rescue someone else and then become incapacitated, you've helped no one, and now you place other rescuers at risk by increasing their workload.
Another class of extinguisher and agent that you probably won't work with, but which is commonly found around aircraft, is Class D. It's for metal fires, such as a magnesium brake or engine fire. These fires are extremely dangerous, extremely hot, and very unstable. Putting the wrong agent on these can increase the fire tremendously, and frequently results in an explosion. A brake fire, for example, can explode violently if sprayed with water. A hot brake may require cooling rapidly (which will destroy the brake, incidentally)...but a metal fire, usually bright enough you can't look at it, will explode if water or other agents are applied.
Specific Class D agents such as Purple K need to be applied properly, and using the proper application and protective equipment...it's a situation when you want to be far away. Reflective suits, specialized breathing equipment, etc, is required.
A good rule of thumb when facing a hazardous materials fire...and there's very little in the hangar or around airplanes that doesn't constitute HazMat, is the thumb-rule: you need to be far enough away that you can hold your fist at arms length extend your thumb, and completely cover the scene from your view. If you're closer than that, you're too close. A good rule of thumb, using a real thumb.
From my perspective as a pilot, having had to discharge extinguishes in the airplane and outside the airplane several times, a DC extinguisher is probably the most messy, but probably the most versatile. It's what I carry in my car, and every year I put out one or two auto fires using a small 10 or 25 BC dry chemical extinguisher (in the USA, the 10 or 25 rating refers to the square footage, or area, expected to be extinguished by the fire extinguisher...the bigger the number, the bigger the extinguisher, and the greater the quantity of fire extinguishing agent).
If you have a chance to get with your local fire department for some hands-on training, it's usually best. It's worth the cost of an extinguisher to have a chance to put out a fuel fire, or extinguish different types of fires. Know what to expect, what to wear (synthetics are like wearing a match stick), and where to stand (upwind). Know how to approach the fire, who to call, when to run away, and how far to go (don't forget the rule of thumb).
If you have a backfire through your intake and end up with an induction fire, remember that the first source of fighting that fire is you...such that fire back into the engine. If it's not working, then don't hesitate to get someone else to discharge a C02, dry chemical, or halon extinguisher to put it out. Make sure you're not cranking the engine or propeller when they approach to do that. If it doesn't go out, don't hesitate to evacuate and abandon the airplane; no sense both of you burning up.
In flight...subject for a whole different discussion...I've had several of these and the most important thing I can tell you is DON'T PANIC. An inflight fire isn't necessarily the end of the world, but it surely could be if you panic.
Enough for now.
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Good reply Guppy and really informative but in Oz, Halon based extinguishers are banned both by Federal law (EPA) and under a treaty for all but limited applications such as inside aircraft, inside ships and armoured vehicles,ie tanks.They are also almost impossible to purchase and need to be check weighed every 3 months under Fed Law
QFF, its worth taking a look at the Fire Protection Association of Australia's web site at fpaa.com.au, particualrly their publications section. For info on Halon agents the applicable publication is the Gas Bag.As it stands there appears to be a major conflict between the CASA rules and the Environment rules on Halon. I spoke to the ALAEA about this months ago but despite trying, they got nowhere.
In the hangar complex that I work in we have foam, dry powder and CO2.The CO2 is specifically for use around electronic compnents as powder destroys
electronic items by getting into minute places and jamming things up. It also sets up corrosion which in electronics is impossible to repair.
To answer you original question. I went to my local fire protection company for advice. They supplied the equipment and also we have a contract to maintain/inspect it every 6 months.The beauty of this is that it each inspection is logged and if we have to make an insurance claim we can prove that it was done. We have water from a hose reel, foam, dry powder and CO2 because its impossible around aircraft and buildings to know what is required until faced with the event.
Wunwing
QFF, its worth taking a look at the Fire Protection Association of Australia's web site at fpaa.com.au, particualrly their publications section. For info on Halon agents the applicable publication is the Gas Bag.As it stands there appears to be a major conflict between the CASA rules and the Environment rules on Halon. I spoke to the ALAEA about this months ago but despite trying, they got nowhere.
In the hangar complex that I work in we have foam, dry powder and CO2.The CO2 is specifically for use around electronic compnents as powder destroys
electronic items by getting into minute places and jamming things up. It also sets up corrosion which in electronics is impossible to repair.
To answer you original question. I went to my local fire protection company for advice. They supplied the equipment and also we have a contract to maintain/inspect it every 6 months.The beauty of this is that it each inspection is logged and if we have to make an insurance claim we can prove that it was done. We have water from a hose reel, foam, dry powder and CO2 because its impossible around aircraft and buildings to know what is required until faced with the event.
Wunwing
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...but in Oz, Halon based extinguishers are banned both by Federal law (EPA) and under a treaty...
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SNS3Guppy 
Great Information - am a firefighter as well and agree with the information.
My 2 cents re flammable liquid fires:
Foam has the advantage that you can use it from a bit further away - as you point the nozzle up so that the foam is 'raining' on the fire to avoid disrupting the foam blanket you've already created. The foam blanket also stops any remaining fuel from emitting vapors - great if there are ignition sources around. Again no good if electrical hazards.
The advantage with CO2 is causes the least damage and mess - but you need to be fairly close to the fire, and if there is any air movement (wind) C02 loses its effectiveness very quickly. The other limitation with C02 is once you stop applying it stops working - if the fuel gets hotter than its autoignition temperature it will reignite, as it will if the vapors reach another ignition source.
Dry Chemicals are messy but effective.
Remember with hangar fires the most important priority is to make sure EVERYONE gets out safely. Only once everyone is safe you can consider fighting the fire to reduce property damage - insurance will cover the monetary losses - fixing people is a lot harder.
Great Information - am a firefighter as well and agree with the information.My 2 cents re flammable liquid fires:
Foam has the advantage that you can use it from a bit further away - as you point the nozzle up so that the foam is 'raining' on the fire to avoid disrupting the foam blanket you've already created. The foam blanket also stops any remaining fuel from emitting vapors - great if there are ignition sources around. Again no good if electrical hazards.
The advantage with CO2 is causes the least damage and mess - but you need to be fairly close to the fire, and if there is any air movement (wind) C02 loses its effectiveness very quickly. The other limitation with C02 is once you stop applying it stops working - if the fuel gets hotter than its autoignition temperature it will reignite, as it will if the vapors reach another ignition source.
Dry Chemicals are messy but effective.
Remember with hangar fires the most important priority is to make sure EVERYONE gets out safely. Only once everyone is safe you can consider fighting the fire to reduce property damage - insurance will cover the monetary losses - fixing people is a lot harder.
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A small correction about the use of Purple K®, Guppy.You're going to be sorely disappointed charging into a metal fire with a Purple K® loaded DC since that powder is only rated BC according to the manufacturer.
A DC loaded with Metl 'X' ® Class D powder would be my weapon of choice here.
RJ
A DC loaded with Metl 'X' ® Class D powder would be my weapon of choice here.
RJ
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RJ Kanary,
You're absolutely correct, thanks.
Have a look here for a metal fire inside a block of dry ice (C02)...interesting.
Demo Lab: Reaction Of Magnesium Metal With Carbon Dioxide
Suffice it to say that metal fires require specialized equipment, not only the agent applied (which varies according to the type of material that's burning), but also specialized protective equipment, too. Reflective high temperature personal protective gear, and and also breathing apparatus. If you've got a metal fire, get far, far away...don't even look at it. It can damage your eyes. It can explode. The vapors are extremely toxic. It's extremely hot. If it's hot enough for the metal to be burning, it's gone far beyond anything you want to be attempting to put out or mess with...time to go.
For very, very small fires of this nature, the most basic type of firefighting agent has long been sand. However, if it's bigger than a road flare, you really don't want to get close enough to put sand on it with a shovel or a spade. Further, many of these fires are self-oxidizing,and can burn under water or when smothered by traditional firefighting agents...this is the fourth part of the fire tetrahedron discussed earlier. What's needed is something to break the chemical reaction that's taking place.
While a Class D fire sounds exotic, around airplanes, it's not. Brake assemblies often contain magnesium, as do many parts of the airplane, including your engine case halves. It's found in alloy in many parts of the airplane, and there airplane is full of flammables and ignitables, as well as ignition sources. Even the brakes are full of flammable fluids, and of course are heat sources themselves.
I've seen batteries melted, and terminals melted off batteries, from cranking too much. I imagine nearly everyone has seen pilots crank an engine until it won't crank any more...even this action can cause a battery to get hot enough that it melts or melts the terminals off. Some types of batteries can reach a combustable state during this time, particularly if receiving a charge from another source...a multi engine airplane that starts one engine and is cranking the other, for example...the rate of charge on the battery can be high enough that in the case of a NiCad battery a thermal runaway occurs. I have seen it melt right through the bottom of the airplane and fall out onto the ramp. A successful engine start may be followed by a high charging rate and a thermal runaway...and even if it's not a NiCad, enough gassing can take place during the charging of a lead acid battery that substantial explosive vapors are formed around the battery and battery case...you've got a mixture of hydrogen and oxygen being given off. Dangerous stuff.
Fires are very possible...but your best course of action may be leaving the area instead of sticking around to fight the fire. Things can be replaced...you can't. And true to RJ Kanary...don't listen to me about purple K. He's or she is right. Thanks for the correction.
You're absolutely correct, thanks.
Have a look here for a metal fire inside a block of dry ice (C02)...interesting.
Demo Lab: Reaction Of Magnesium Metal With Carbon Dioxide
Suffice it to say that metal fires require specialized equipment, not only the agent applied (which varies according to the type of material that's burning), but also specialized protective equipment, too. Reflective high temperature personal protective gear, and and also breathing apparatus. If you've got a metal fire, get far, far away...don't even look at it. It can damage your eyes. It can explode. The vapors are extremely toxic. It's extremely hot. If it's hot enough for the metal to be burning, it's gone far beyond anything you want to be attempting to put out or mess with...time to go.
For very, very small fires of this nature, the most basic type of firefighting agent has long been sand. However, if it's bigger than a road flare, you really don't want to get close enough to put sand on it with a shovel or a spade. Further, many of these fires are self-oxidizing,and can burn under water or when smothered by traditional firefighting agents...this is the fourth part of the fire tetrahedron discussed earlier. What's needed is something to break the chemical reaction that's taking place.
While a Class D fire sounds exotic, around airplanes, it's not. Brake assemblies often contain magnesium, as do many parts of the airplane, including your engine case halves. It's found in alloy in many parts of the airplane, and there airplane is full of flammables and ignitables, as well as ignition sources. Even the brakes are full of flammable fluids, and of course are heat sources themselves.
I've seen batteries melted, and terminals melted off batteries, from cranking too much. I imagine nearly everyone has seen pilots crank an engine until it won't crank any more...even this action can cause a battery to get hot enough that it melts or melts the terminals off. Some types of batteries can reach a combustable state during this time, particularly if receiving a charge from another source...a multi engine airplane that starts one engine and is cranking the other, for example...the rate of charge on the battery can be high enough that in the case of a NiCad battery a thermal runaway occurs. I have seen it melt right through the bottom of the airplane and fall out onto the ramp. A successful engine start may be followed by a high charging rate and a thermal runaway...and even if it's not a NiCad, enough gassing can take place during the charging of a lead acid battery that substantial explosive vapors are formed around the battery and battery case...you've got a mixture of hydrogen and oxygen being given off. Dangerous stuff.
Fires are very possible...but your best course of action may be leaving the area instead of sticking around to fight the fire. Things can be replaced...you can't. And true to RJ Kanary...don't listen to me about purple K. He's or she is right. Thanks for the correction.
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It's a he. Honest.Now for the thread drift part. 
My Dad was a charter member of the local VFD up in the boonies where I grew up. As soon as he figured his boys were old enough to not do something that would kill themselves (or anybody else.) ,we started out at the bottom of the ladder, literally at the VFD.
The very first fire scene I was allowed on to was a garage fire started by a controlled burn that became uncontrolled.Inside this garage was an ancient Lawn Boy® mower. You know what they were constructed from. <G> {Magnesium. The Wonder Metal.}
A man with far more experience and knowledge than myself decided he was going to put out that incandescent white glow with a booster line.I yelled at him not to and hit the dirt as he opened the nozzle.
That pretty much finished the garage off.Dad commented later on how it must have been that I really did pay atteniton in chemistry class, and at the County Fire School. <VBG>
RJ
My Dad was a charter member of the local VFD up in the boonies where I grew up. As soon as he figured his boys were old enough to not do something that would kill themselves (or anybody else.) ,we started out at the bottom of the ladder, literally at the VFD.The very first fire scene I was allowed on to was a garage fire started by a controlled burn that became uncontrolled.Inside this garage was an ancient Lawn Boy® mower. You know what they were constructed from. <G> {Magnesium. The Wonder Metal.}
A man with far more experience and knowledge than myself decided he was going to put out that incandescent white glow with a booster line.I yelled at him not to and hit the dirt as he opened the nozzle.
That pretty much finished the garage off.Dad commented later on how it must have been that I really did pay atteniton in chemistry class, and at the County Fire School. <VBG>
RJ
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Great discussion.
I know we are discussing ground fires, not in-flight fires, but I am always wary when pilots start discussing the 'hazards' of Halon extinguishers.
Interestingly, Halon extinguishers remain a popular option for computer rooms (real computers, not these toys on our desks etc) and archives of rare documents - primary reasons include no damage due to the extinguishing agent, the agent is a gas that leaves no residue, and low toxicity for the humans that may enter shortly after the fire is extinguished!!
This FAA AC on use of hand fire extinguishers has some interesting points to make, including.....
7. CAN HALON CAUSE HARM TO PASSENGERS AND CREW?
a. Generally speaking, no. Various publications, including AC 20-42C, caution against exposure to “high levels” of Halon in confined spaces, citing the possibility of dizziness, impaired coordination, and reduced mental sharpness. AC 20-42C also provides guidelines that describe what is meant by the term “high level” and further states that these levels should not be exceeded in ventilated or non-ventilated passenger compartments on aircraft. However, studies have shown that discharging all of the hand-held Halon extinguishers required by regulation in the passenger cabin of an air carrier aircraft will not exceed the maximum concentration levels of Halon vapor specified in AC 20-42C or by NFPA 408 guidelines.
b. NTSB investigations of in-flight fires indicate that crewmembers have been hesitant to use Halon extinguishers during flight because of mistaken ideas about adverse effects of Halon. In one instance, a flight attendant went to the flight deck to inform the flightcrew of a fire and asked the captain whether to spray Halon into a vent where she suspected a fire. The captain instructed her not to use the Halon extinguisher, indicating he was concerned about spraying Halon in the cabin. In another instance, an off-duty company pilot considered using a Halon fire extinguisher, but decided against doing so because he was concerned that the Halon “would take away more oxygen.” In each instance, the crewmembers lost critical time and delayed the aggressive pursuit of the fire.
c. The NTSB has expressed concern that risks of exceeding the maximum recommended levels of Halon gas outlined in AC 20-42C have been overemphasized in crewmember training programs, especially when compared to the risks of an in-flight fire. The NTSB emphasizes “…that the potential harmful effects on passengers and crew [of Halon] are negligible compared to the safety benefits achieved by fighting in-flight fires aggressively.” The toxic effects of a typical aircraft seat fire, for example, far outweigh the potential toxic effects of discharging a Halon fire extinguisher.
I know we are discussing ground fires, not in-flight fires, but I am always wary when pilots start discussing the 'hazards' of Halon extinguishers.
Interestingly, Halon extinguishers remain a popular option for computer rooms (real computers, not these toys on our desks etc) and archives of rare documents - primary reasons include no damage due to the extinguishing agent, the agent is a gas that leaves no residue, and low toxicity for the humans that may enter shortly after the fire is extinguished!!
This FAA AC on use of hand fire extinguishers has some interesting points to make, including.....
7. CAN HALON CAUSE HARM TO PASSENGERS AND CREW?
a. Generally speaking, no. Various publications, including AC 20-42C, caution against exposure to “high levels” of Halon in confined spaces, citing the possibility of dizziness, impaired coordination, and reduced mental sharpness. AC 20-42C also provides guidelines that describe what is meant by the term “high level” and further states that these levels should not be exceeded in ventilated or non-ventilated passenger compartments on aircraft. However, studies have shown that discharging all of the hand-held Halon extinguishers required by regulation in the passenger cabin of an air carrier aircraft will not exceed the maximum concentration levels of Halon vapor specified in AC 20-42C or by NFPA 408 guidelines.
b. NTSB investigations of in-flight fires indicate that crewmembers have been hesitant to use Halon extinguishers during flight because of mistaken ideas about adverse effects of Halon. In one instance, a flight attendant went to the flight deck to inform the flightcrew of a fire and asked the captain whether to spray Halon into a vent where she suspected a fire. The captain instructed her not to use the Halon extinguisher, indicating he was concerned about spraying Halon in the cabin. In another instance, an off-duty company pilot considered using a Halon fire extinguisher, but decided against doing so because he was concerned that the Halon “would take away more oxygen.” In each instance, the crewmembers lost critical time and delayed the aggressive pursuit of the fire.
c. The NTSB has expressed concern that risks of exceeding the maximum recommended levels of Halon gas outlined in AC 20-42C have been overemphasized in crewmember training programs, especially when compared to the risks of an in-flight fire. The NTSB emphasizes “…that the potential harmful effects on passengers and crew [of Halon] are negligible compared to the safety benefits achieved by fighting in-flight fires aggressively.” The toxic effects of a typical aircraft seat fire, for example, far outweigh the potential toxic effects of discharging a Halon fire extinguisher.
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In that confined of a space, my choice would be Halon over DC anyday.Have you ever been in a small room with NO fire, and someone empties out a five pound straight shooter? You won't need Tums® for a month. <G>
RJ
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What steps to take when confronted with an aircraft fire, particularly in a hangar?
Large ones and lots of them away from the fire. I would prefer to leave it to the professionals who are fully trained and kitted up.
If they dont get there in time to save the aircraft/hangar, thats what insurance is for. No amount of insurance is going to replace a life lost through an amateur attempt to extinguish a fire.
Large ones and lots of them away from the fire. I would prefer to leave it to the professionals who are fully trained and kitted up.
If they dont get there in time to save the aircraft/hangar, thats what insurance is for. No amount of insurance is going to replace a life lost through an amateur attempt to extinguish a fire.
for a magnesium or aluminum fire if no class D extinguisher is available the procedure is to smother in graphite---says it right on the bottle --- I love playing with that stuff sodium too ---I think the same procedure applies to nuclear reactor meltdowns ---
PA
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smother in graphite
I think the same procedure applies to nuclear reactor meltdowns ---
Surely a tough choice.......how long do you continue to smother the reactor in graphite whilst your newly developed fifth testicle grows into a watermelon....
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Where to obtain a BCF / Halon extinguisher
After a bit of a search, I'm adding a reply to this old thread rather than raising a new one.
After some research, I'm lead to believe a BCF / Halon extinguisher is still the recommended option for carrying in the cabin of a light aircraft to fight an in-flight fire. For this reason there is an exemption for aircraft use in the regs that ban them for just about all other purposes.
Does anyone know where to obtain one in Australia? Unfortunately you can't easily order one from USA as they are hazardous from a shipping perspective.
After some research, I'm lead to believe a BCF / Halon extinguisher is still the recommended option for carrying in the cabin of a light aircraft to fight an in-flight fire. For this reason there is an exemption for aircraft use in the regs that ban them for just about all other purposes.
Does anyone know where to obtain one in Australia? Unfortunately you can't easily order one from USA as they are hazardous from a shipping perspective.
