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I use this exact container and pump. I went to Grainger and got a grounding cable and attached it to one of the hangar steel beam bolts going into the ground. I attach the clamp to my grounding point on the RV and attach the ground cable on the pump to the grounding cable, as well.
This connects the pump cart to the airplane but what about a ground?
I don't understand the purpose of connecting the (tied together airplane and fuel rig) to the hangar or a true "ground". Seems to me (and I'm professing ignorance and a desire to learn) that as long as the airplane and fueling rig are tied together, there is no need to tie that assemblage to anything else.
I agree. As long as the airplane and the fueling tank have the same electrical potential, should be no static spark. Grounding the fueling tank to the airplane should cover that.
Static electricity is generated when a low conductivity fuel like petrol flows in a non-conductive pipe. Negative charges accumulate on the pipe wall and positive charges are carried away with the fuel. This charge separation is a similar to what happens when two non-conductive materials are rubbed against each other.
I don’t have a real answer, But my guess is that Aircraft take a lot more fuel than those other machines and the act of transferring the larger volume increases the chances of creating static
I don't have the answer either. I do know that when you buy fuel at the self serve area at the FBO the ground is a true ground (as in it is not the pump connecting to the aircraft). I just assumed (perhaps ignorantly) that grounding the airplane actually meant a cable connected to a grounding rod.
But I am not incorrect on my assumption that I will continue to ground my airplane when refueling. You can do as you wish. There is a reason you ground the plane to refuel whether either of us know it or not.
This is one reason the self serve pumps at your local gas station pump at a very slow rate..... but, not the only reason.
Please explain why the self serve pumps have a ground wire that is actually attached to a grounding rod stuck in the ground and does not have a bonding wire between the pump and the aircraft. Not being argumentative; seriously would like to know. As you have put it then it seems what the FBOs are providing leaves us at risk.
If the pumps are at ground potential, they are more protected from other mishaps beyond a static charge build up when refueling your plane (as in an electrical fault of some kind). Have you ever been ”bitten“ when touching an electric motor with dodgy wiring? As already discussed, grounding your plane to this same point helps to mitigate a voltage buildup along the fuel line. The fact that this ground post provides other functions is not specifically applicable to plane refueling.
I can only explain my understanding of the physics. I can't explain why others do what they do. I will say that I've never seen an airport fuel pump or truck without an additional retractible bonding wire, even though the hose itself has an imbedded grounding wire, nor have I have seen an airport fuel truck with a bond to ground.
I thought the grounding cable at the self serve pump was connected to the pump. Maybe also to a ground rod pounded down into the ground, but is it not electrically connected to the pumping apparatus? I’m going to look closer next time I get self serve fuel.
Good point. I suspect grounding to earth at the pump (if it exists...I can't recall seeing such a thing but I'll look closer next time) is about motor wiring rather than static charge. Should be no reason (that I can think of) relative to electrical potential differences to bond the pump to earth nor the airplane to earth.
Amen.
I don’t think there’s enough carbon in tires to provide a pathway at only 12v potential.
The aircraft and fueling device need to have the same electric potential so there is not static spark when the fuel nozzle approaches the metal fueling port. The issue is the aircraft tires are an insulator to earth ground and, heck - this guys says it better --->
Started a reply, Bill's is better than my Sunday morning ramblings. Main item is to ground all items BEFORE fueling and unground AFTER fueling. Years ago after landing the Lear 35, the line dude walked around and touched the tip tank walking to his fuel truck. That spark knocked him back a few feet, told him "your grounded Kid!"
I beg to differ - Years ago after landing the Lear 35, the line dude walked around and touched the tip tank walking to his fuel truck. That spark knocked him back a few feet, told him "your grounded Kid!"
Hoping to be educated here....I was following you right up to this point...having trouble making the connection. Could you elaborate on why it's important to ground to earth?
I have a few of those and I agree, they work surprisingly well. I use them for the diesel rolling stock, another one for mowers, and have one in the hangar.Coming back to the OP's need to transfer fuel... If anybody is looking for an inexpensive way of doing it, this (or a very close relative) is what I've been using for years.
Battery-Operated Liquid Transfer Pump
Amazing deals on this Transfer Pump Battery Operated at Harbor Freight. Quality tools & low prices.www.harborfreight.com
I'm constantly surprised how well this work. Yes, the pump is doing some of the work and siphon effect is doing some of the work. A pair of D-cell batteries lasts a long time (like a year's worth of flying!).
When the jerry can is empty or I've transferred as much fuel as I wish, the pump is turned off and removed from the jerry can, allowing any remaining fuel to drain downhill into both the aircraft and the jerry can.
This is about as simple and cheap a pumping system as one can get, and, in my experience, it has proven to be very effective.
Grounding to the earth could have a significant impact if the fueler approaches an open fuel tank while being grounded to earth but not the plane. When I was in a military flying club we were required to ground the truck to the earth, the plane to the earth, and the plane to the truck or pump when refueling. Those were our instructions and we followed them. I suspect that this procedure eliminates almost all risk. We also stopped fueling when lightning approached to a specified distance I believe, but my memory escapes me on the distance. Fuel vapors are dangerous critters. The danger is NOT overrated. I have not seen a plane fire from refueling but I did see a yacht flash fire due to improper fueling procedures. It WILL make a believer out of you when you see how far and fast that fuel vapor fire flame front propagates and the energy released. On the occasion of the yacht fire, I saw a person who could not swim jump overboard with the assistance of the shock wave (he was rescued). It was something I will never forget.
I’ve been transferInv petrol in ne form or another for like ever in less than ‘ideal’ ways and I’m still here!
I've done many dangerous things in my life and I'm still here, but I strongly recommend that people not repeat the dangerous things I've done.There’s a lot of fear attached to this concept. Hydrocarbon products are being transferred world wide every second of the day, if the boogeyman was that scary there’d be no one left on the planet
