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Fire!

Vern

Well Known Member
I stopped by another hangar this morning and got into a lengthy discussion about all the airplane/hangar fires we have seen and heard about.

I wanted to start this thread so newbies in particular won't repeat these dangerous situations.

My friends told of plane after plane they had known off or witnessed where a fire destroyed or damaged someone's dreams.

They told of a twin which had a visible fuel leak on a turbo charged (hot) engine that the pilot insisted on flying.

A 700k plane burned up when the dehumidifier in the T hangar caught fire.

A Skylane which was flown even though fuel was dripping constantly from the wing.

A mechanic who was draining fuel tanks on a twin when it burst in to flames from a static discharge. It was sitting in the hangar in the same spot where a plane had caught fire the month before.

They spoke of a puddle of fuel on the hangar floor which was ignited when a person drug some insulation across the floor nearby. The flames went from the puddle to a nearby plane.

I had a brand new RV catch fire in my hangar while the tanks were being calibrated for an EFIS.

I pulled a man out of a burning plane which had a fuel line fitting come loose after an engine install. The fitting had never been tightened .

I sat with a mechanic who was working on a fuel system on a twin. He was interrupted and missed a fitting when he resumed work. After he cowled it up, six people took off in the twin which exploded within his sight. How'd you like to have that memory?

I used to work in a shop where the IA kept a bottom third of a 55 gallon barrel full of fuel out on the hangar floor for parts cleaning. He would clean parts in it with a cigarette dangling from his mouth!

I helped out an RVer whose RV burst into flames during runup when the copper primer line broke. His shoes were melted to the floor. In a moment every wire and hose FWF was toasted.

There are more stories, but the point is: many folks may not realize how dangerous fuel is and the fire danger we face with airplanes. Something as simple as calibrating a fuel system can have horrible results.

Never work on draining tanks, etc inside a hangar. Work only on humid days, not dry days when static is common.
Ground the plane and fuel containers when you do. Have extinguishers right there where they would be needed. Have a buddy helping watch for static flashes,etc. Triple check all fittings!. Check them when you uncowl.

What are some other tips you know of?
 
This was my first experience with how flammable - combustible oil is, a long time ago, in a galaxy far far.....anyway, we just finished building and installing this wicked BBC and TH 400 in my buddy's 70 Chevelle, on initial start, lots of stress, excitement, exhaust noise, Beer, no wait.....running around we went immediately to 2000 RPM for cam break in, and in a hurry set timing, keeping radiator full after thermostat opening, toping off transmission fluid and that's when the trans dipstick fill tube burped oil out and immediately ignited on the hot headers, flames will get your attention real quick. so moral of the story is, oil will burn just like gasoline under the right conditions, like our oil cooler lines right above our exhaust!
 
What are some proper ways to ground both the airplane and fuel container when draining fuel? What do you ground to? Do you ground the plane to the container?

I have a bolt into the concrete floor of my hangar that makes a convenient ground point but I have to run a fairly long wire when draining outside my hangar. I don't know how to calculate resistance in air when trying to figure out how long the wire would need to be to make it more attractive for the electrons to spark a short distance in air, rather than run along the wire:eek:

Curious as to various peoples' approaches.
 
oil drips from breather hose

So is it conceivable that my breather line dripping on the exhaust could ignite? It seems to be fine and I know the valve from Antisplat drips it right into the path of the exhaust.... without any fires that I have heard of.
 
What are some proper ways to ground both the airplane and fuel container when draining fuel? What do you ground to? Do you ground the plane to the container?

Jeremy, I have a homemade de-fueler rig I've used for years. It's mostly a matter of tying everything together electrically so no difference in potential can build between components and discharge as a spark..

Start with a large metal funnel. Firmly rivet on three wire leads. One is fairly long, with a substantial clip on the free end (like a battery charger clip). The second is medium length, again with a clip. The third is about 18", with the last 6" or so stripped bare.

Position the gasoline container under the tank drain. Feed the short bare wire into the container so it reaches all the way to the bottom, then insert the neck of the funnel. Clip the medium length wire to the airframe, and clip the long lead to a good local ground, like a rod driven into wet dirt, or a nearby hangar frame slab bolt.

Don't forget to discharge yourself before reaching into the fuel vapor zone.
 
DanH De-fueler

Is it OK to use a plastic fuel container if you run a lead into it?

If you used a metal container could you just clip the funnel lead to it without the wire into the bottom?

What gauge wire works?
 
Is it OK to use a plastic fuel container if you run a lead into it?

If you used a metal container could you just clip the funnel lead to it without the wire into the bottom?

What gauge wire works?

http://www.shimadzu.com/an/hplc/support/lib/lctalk/14/14lab.html

This might help. Any gage works, put a weight on the end (nut) and run the wire out the vent hole of a plastic container.

Oh - 30,000 volts can be generated in 6" of plastic tubing with high fuel flows, so caution, it does not take much length. Using clear vinyl is good to see if air is in the fuel, but it does not take much length.

Hey Vern, with stories like that you could sell insurance.
 
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I have a zinc eye bolt anchored in the concrete floor , I use it to attach a tie down strap to pull the tail down and check my nose wheel . Is it fesible to ground the plane to that bolt if need be?
 
I have a zinc eye bolt anchored in the concrete floor , I use it to attach a tie down strap to pull the tail down and check my nose wheel . Is it fesible to ground the plane to that bolt if need be?

A ground point should be a copper rod driven several feet into the soil. I would imagine an eye bolt drilled into the concrete floor would be a very poor conductor. If you don't want to drill a hole and drive a 4' copper rod, a better solution would probably be to ground to a piece of steel hangar structure, since the hangar itself is <probably> well grounded.
 
Imagine a day when your entire airframe is a solid state structural battery that can't ignite and just has a plug in motor with no wire connections to fail. The stories are gonna get so boring.
 
Gasoline flowing thru a nonconductive plastic or rubber fuel line/funnel/whatever makes a pretty darn good Van de Graaff generator. Ever wonder why teflon fuel hose has a conductive carbon liner inside?
 
A ground point should be a copper rod driven several feet into the soil. I would imagine an eye bolt drilled into the concrete floor would be a very poor conductor. If you don't want to drill a hole and drive a 4' copper rod, a better solution would probably be to ground to a piece of steel hangar structure, since the hangar itself is <probably> well grounded.

Good point. I therefore Delete stupid question.
 
Electrical fires

Fuel fires are dangerous but they are not the only type of fires that occur in airplanes.

Electrical fires can occur for many reasons including chafed insulation causing a short; improper gauge wire; old / stuck breaker; dirt in a reostat; critters chewing on wires; failed voltage regulator; yada yada

Toxic fumes and smoke can put an end to your day even if the heat of the fire doesn't.
 

Great link Bill.

Is it OK to use a plastic fuel container if you run a lead into it?

Sure hope so!

Seriously, the plastic container is in contact with the metal funnel, the fuel in the container, and the submerged wire, and all are electrically common.

If you used a metal container could you just clip the funnel lead to it without the wire into the bottom?

Yes, but as noted in the page Bill linked, a metal can may have a liner or other interior coating. I would always use the submerged wire.

What gauge wire works?

Mine is ordinary stranded lamp cord.
 
Personal ground

(snip)...
Don't forget to discharge yourself before reaching into the fuel vapor zone.

How about a personal wrist strap ground?
In our data centers, we had to wear wrist ground straps. They have a coiled wire with an aligator clip. Seems like a good way to keep your body at the same ground potential.
 
How about a personal wrist strap ground?
In our data centers, we had to wear wrist ground straps. They have a coiled wire with an aligator clip. Seems like a good way to keep your body at the same ground potential.

That'll work, especially if you attach the strap to the same structure as everything else ...

Thanks for this thread BTW, I had no idea flowing liquids could cause static!
 
Fire danger

Didn't see it specifically mentioned, but everyone probably knows that it is the gasoline vapors which are most dangerous.
 
Thanks everyone and Dan especially. Next trip to the hangar I'll make the funnel mods and clip it directly to the hangar!
 
cars?

Isn't it odd that we don't ground cars as we fuel them?

I have heard of a few cases of static-discharge from a person to the car igniting the vapor cloud surrounding a car while being fueled on a very still day with the pump in a fairly sheltered area. But incredibly rare.
 
Isn't it odd that we don't ground cars as we fuel them?

I have heard of a few cases of static-discharge from a person to the car igniting the vapor cloud surrounding a car while being fueled on a very still day with the pump in a fairly sheltered area. But incredibly rare.

SSShhhhh!! We blame those on cell phones. :cool:
 
End of fuel-hose into the fuel

When I refuel, (after installing the grounding wires ofcourse) I put the end of the refueling nozzle down INTO the fuel so it's below the surface of the fuel.

That way, the fuel flowing out of the nozzle, has no contact with air on it's way into the fueltank.

This ofcourse only works when there's enough fuel in the tank before starting to refuel.

If there's not enough fuel, I refuel as normal until the fuel-level increases and then the end of the fuelnozzle can be put below the fuel-level.

I was taught this technique by an old IP a long time ago.

Can anyone tell me if this is a good idea? It makes sense to me...?
 
Isn't it odd that we don't ground cars as we fuel them?

I have heard of a few cases of static-discharge from a person to the car igniting the vapor cloud surrounding a car while being fueled on a very still day with the pump in a fairly sheltered area. But incredibly rare.

The handle/nozzle and hose on automotive fuel pumps are internally grounded and ground the automobile when they contact the fuel filler receptacle.
 
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