Fire extinguisher vs electrial fire

[slick1537]

I was looking over the EPs for the R22 today in preparation for my commercial check ride and I had a question. We established in an earlier thread that you never want to dump water on an electrical fire, since water conducts and could aggravate the fire. My question is if the fire extinguisher equipped on the R22 is OK to use on an electrical fire? Are all extinguishers equipped created equal or does their composition vary from ship to ship?

[Goldy]

My question is if the fire extinguisher equipped on the R22 is OK to use on an electrical fire? Are all extinguishers equipped created equal or does their composition vary from ship to ship?

 

Class A extinguishers are for ordinary combustible materials such as paper, wood, cardboard, and most plastics. The numerical rating on these types of extinguishers indicates the amount of water it holds and the amount of fire it can extinguish.

Class B fires involve flammable or combustible liquids such as gasoline, kerosene, grease and oil. The numerical rating for class B extinguishers indicates the approximate number of square feet of fire it can extinguish.

Class C fires involve electrical equipment, such as appliances, wiring, circuit breakers and outlets. Never use water to extinguish class C fires - the risk of electrical shock is far too great! Class C extinguishers do not have a numerical rating. The C classification means the extinguishing agent is non-conductive.

Class D fire extinguishers are commonly found in a chemical laboratory. They are for fires that involve combustible metals, such as magnesium, titanium, potassium and sodium. These types of extinguishers also have no numerical rating, nor are they given a multi-purpose rating - they are designed for class D fires only.

 

OK so Fire 101 aside, look at the rating on the extinguisher to determine what type(s) of fires you can use it in. In reality, can you imagine dumping an extinguisher inside of the cabin with doors on? Talk about instant IMC !!!

 

Smell smoke, see smoke.

 

Turn off Master

Turn off cabin heat

Open vent to full

Find a place to land...now.

 

Any others I missed?

 

Fly safe,

Goldy

[DanceswithCyclic]

That would depend upon the Class of extinguisher actually in the cockpit.

However, an electrical fire will probably continue to re-ignite after spray as long as power is still energized.

 

Class A is for flammable solids (wood, paper, clothing)

Class B is flammable liquids (dead dinosaurs in all forms)

Class C is Electrical (non-conductive suppressant)

Class D is Chemical fires only (and nasty stuff like burning Magnessium)

 

My source is http://www.fire-extinguisher101.com/

[slick1537]

Personally I wonder if solo I would even be able to reach the fire extinguish on the r22 while still flying.

[kodoz]

The procedure for any in-flight fire (R22/44) involves landing before attempting to extinguish. For electrical, cutting the power (master and alt --> off) will stop the fire *if* it hasn't ignited insulation, etc. If you still have a fire after cutting the power, you don't have an electrical fire.

[BOATFIXERGUY]

Let's remember though, the aircraft fire extinguisher is really meant to put out fires on occupants, not burning aircraft. The tiny little extinguisher in aircraft really isn't going to suffice in putting out a fire in an aircraft. Although I have used one to put out an oil fire, after I landed, on a turbo-charger. But again, it's designed for the occupants.

[AngelFire_91]

If you really want to get technical, a Class C fire is actually "Energized" electrical, so if there is no electricity getting to it then it is a Class A fire.

[lelebebbel]

the electrical system in the R22 operates at 12-14V. Water does not conduct electricity very well and would certainly NOT aggrevate an electrical fire on a low voltage system like this. You could throw the battery in the bathtub and nothing would happen.

 

An electrical fire happens when something, like wire insulation, is ignited by an electrical short or sparks, so the best way to extinguish it would be to stop the source of ignition (turn of electricity), then use a fire extinguisher suitable for the burning material.

If that happens to be fuel or oil, water is not a good idea. I think the R-22 FE is a foam type ABC unit but i could be wrong.

[Hedge36]

Personally I wonder if solo I would even be able to reach the fire extinguish on the r22 while still flying.

 

Which is why it's "over there". Can you imagine trying to manhandle the Tilt-A-Whirl to a semi-safe landing while fumbling with "pull pin, aim at base of fire, pull trigger... crap, what's it say? I can see a damn thing!" Screw that. Hull insurance is there for a reason.

[jehh]

If you're on the ground safety and the aircraft is on fire, run for it. The extinguisher is for people, not the aircraft. The aircraft is insured, contains a lot of flamable material, and you'll never put out a serious fire with that little thing anyway.

 

If the president of the insurance company was standing there, he'd tell you to let it burn and get away to a safe distance. I've been told over and over by insurance that they care far more about people than the hull. The hull is a $100,000 claim, the people are a $1,000,000 claim.