I’m getting ready to do leak checking, fuel flow testing, gage calibration, etc. These tasks require a fair amount of moving fuel around and I want to be sure I don’t burn down my plane.

Any tips on how to reduce the risks while draining fuel would be greatly appreciated.

Screw the plane...save your skin!

Aside from eliminating the common spark hazards (steel tools, pilot lights, batteries, compressor motors that automatically start, etc.), static electricity is the biggest danger.

Bond all containers AND fuel lines while transferring fuel. You want every part of the fuel system to have the same electrical charge so a static spark doesn't jump from one side to the other. A stream of fuel falling through air can get a static charge, and the amount of charge necessary to ignite fuel vapors is about the same amount required for a fly to flap its' wings.

Since fuel transfer lines are generally plastic and cannot be bonded, I run lengths of beaded wire (like what you'd use to hang a badge around your neck) through my fuel lines and bond each end. If at all possible, use steel fuel cans and bond them to the ground. Keep in mind that the paint on the can will interfere with an electrical bond.

Do not wear nylon or synthetic clothing...it creates too much static electricity. Rub your cotton clothing and any airplane upholstery with dryer sheets to further reduce static build up. While mixing napalm (for firefighting) we actually bonded ourselves to a ground stake with clips and wires attached to our clothing.

Good ventilation will help keep the vapor concentration from reaching dangerous levels. Remember that fuel vapors will travel along the ground and can be ignited from distant sources. Do not leave any fuel open to the air...seal all containers immediately.

Fire extinguishers are cheap. I'd be sure to have several LARGE halon extinguishers in the immediate area.

Smoke as little as possible while working...

good luck!

Good advice from Hammer. The key is Bonding......not necessarily grounding, your goal is, as Hammer said, to have everything that comes in contact with the fuel at the same electrical potential.

Allowing fuel to drop any distance into a container is an invitation to trouble, since falling fuel is developing a potential.

Remember, it's not the liquid fuel that will light, it's the vapor cloud that is emitted by that liquid fuel, and it is virtually impossible to see that cloud.

Make sure YOU are bonded to the fuel handling materials as well. Just walking across the hangar can generate enough of a static charge to throw a spark when you touch the plane.

Fuel fires are actually pretty rare, but if you're ever around one, you'll be VERY motivated to take every precaution possible to avoid another.

MTV

Don’t do it in a hangar, unless it is yours and stands alone. You don’t want to be the guy that burned the whole hangar and all your neighbors planes up.

jugheadF15 wrote:Don’t do it in a hangar, unless it is yours and stands alone. You don’t want to be the guy that burned the whole hangar and all your neighbors planes up.

What if the other hangars in the row are full of boats, RVs and other non aviation stuff[emoji57]

Thanks for the tips guys. I'll need to figure out a way to contain the fuel during flushing and flow testing rather than letting it fall into a bucket or whatever.

jugheadF15 wrote:Don’t do it in a hangar, unless it is yours and stands alone. You don’t want to be the guy that burned the whole hangar and all your neighbors planes up.

I second this.

Two or three years ago a couple of hangars (airplanes included) burned to the ground at Ellensburg (KELN) when a mechanic drained fuel into a bucket below the wing quick drain. Accoding to the fire dept report the A&P dropped a rag which had a static charge... it sparked and fumes ignited. I did a google search afterwards and found several hangar fire stories from around the US. Most related to fueling/defueling. A couple were fatals.

That little bit of pokin' around really changed my attitude toward messing with fuel in enclosed spaces, or even with the door fully open.

Wee
don’t let your kids smoke around the plane while you are defuleing it. Have a couple 5#ABC fire extinguishers handy. I touch everything around me prior to exposing vapors

On storage, something that worked for me: I got in touch with a local motorcycle racer I know, and got my hands on several 15 gallon metal fuel drums they didn't need any longer. They are metal (meaning easy to bond to the airplane) and seal up very well. I used them when I drained ~50 gallons out of my plane prior to fuel tank removal, and will just pump the fuel out of them back into the airplane when I'm ready to use it again. They also stack nicely.

There should be some car/motorcycle race clubs somewhere near you, get in touch with them and see if anyone has said containers. They aren't really worth anything once emptied of their magic go juice, and the drums are more economical for the racers so they are fairly common.

All advice here on bonding and static avoidance is crucial. I made a length of wire with a battery clip on each end, one for the drum and one for something metal on the airplane. I also grounded the airplane to earth ground (electrical conduit) figuring the self-service fuel pumps do it too, so why not. I didn't ground the plastic tubing (though I like the idea of metal in the line) but also made sure the ends were resting on the bottom of the containers. For transfer I used a GasTapper 12v fuel pump and just ran mogas through it when done to flush the 100LL out and protect the plastic bits. The plane was out of the hangar and I had multiple extinguishers nearby, though those cute little bottles won't really do shit for an open fuel fire, they are mostly to let you get away from it.

One other thing - limit the fuel available to burn. You can't ignite what isn't present. When I did mine, as soon as a drum was filled up I sealed it and moved it away from what I was doing. It may not save the airplane, but it can prevent a lot of collateral damage. Obviously if you are filling the wings up that becomes less possible as you go, but no sense having more in the vicinity than you actually need at the time.

Now, this isn't to say that you need to shut off every phone within 1000 yards and evacuate the facility. Fuel fires are rare for a reason, and fairly basic safety precautions will sort it out. You just need to apply them consistently and deliberately and you'll be fine. The simple fact that you asked and are trying to think it through means you will be fine with it.

Hammer's post is right on! I used to haul fuel for a living and had to attend a whole bunch of safety classes for every refinery we hauled from. One thing that isn't mentioned and is VERY important is that fuel vapors are heavier than air. This is important to remember and to think of in that the vapors are what's flammable, and where they lurk may surprise you!! One of the scariest things for me when I was filling a gas station's tanks was someone walking toward me with a cigarette...then they throw it on the ground to put it out....that's THE worst thing to do!!! We had one exercise that we were simulating a spill and they used smoke to show where the vapors were going.... absolutely astonishing how they flowed into places I never would have guessed!
Be safe Jon!
John

Thanks for the tips guys! I'll perform the flow testing outside; I need to find a hole to push the tail into anyways to achieve max climb angle. Bonding and fire extinguishers will be on hand.

I'm a chicken when it comes to fuel vapors. I run the bilge fan in my boat pretty much constantly because I'm paranoid about the thing blowing up when I hit the start switch.

I put a couple gallons in each tank and found that my engine driven fuel pump leaked. I sent the entire injection system out for overhaul so it will be a couple weeks before I get back to the fuel system. I really wanted to start the engine today...

Just wanted to drop some links to past discussions...entertaining, but some good info nevertheless.

https://backcountrypilot.org/forum/explosive-subject-plastic-gas-cans-887
https://backcountrypilot.org/forum/it-really-can-happen-fueling-fire-5279
https://backcountrypilot.org/forum/mogas-users-how-do-you-fuel-your-plane-16630

Don’t forget that screw guns/drills will ignite vapor.

I know someone that happened to. It cooked him. He’s a mess.

Fuel trailer/defueler. During defueling I bond this to the airplane and ground.

Another means to help with bonding: connect a piece of safety wire to drain, and connect it at bottom to metal receptacle. The wire should help to maintain a bond, even though fuel is flowing through plastic hose.

MTV