OregonMaule wrote:My hose on my 100 gallon bed tank has BONDED printed right on it. I buy my Mogas at Pacific Pride. Their hose says bonded. Next time I get 100 LL I'm going to look at the hose.
Cheers
I think the only thing that bonded fuel hose does is to help static generated by the flowing fuel to dissipate more readily, vs pure rubber hose which can retain static longer until a big discharge. While the bonded fuel hose may help the issue by adding some layer or mesh of conductive material to help the static dissipate, the problem of having a potential between the filler nozzle and its shroud of fuel vapors, and the aircraft itself, still exists.
We're lucky that fueling accidents happen so rarely. I think the atmospheric conditions and other factors have to be just right to make the static discharge possible, and even then the discharge has to be of a certain magnitude to act as an ignition. It did happen to one of my old instructors though. Better safe than sorry. As to why it's safe in a conventional automobile fueling operation, I'm still not sure. Either static is not being allowed to build up because of the fancy hose, or it's being discharged at first contact of the filler nozzle with the car.
So, a couple different scenarios:
-Fueling cars from pump
-Fueling cans from pump
-Fueling aircraft from pump
-Fueling aircraft from truck
-Fueling aircraft from cans
Each of these has its own consideration that can often turn this topic into 20 pages of forum thread.
http://www.fs.fed.us/t-d/pubs/pdfpubs/pdf95512323.pdf