I refuel my Safari helicopter from a 28 gal plastic fuel caddy that has a
rotary pump installed. I have a ground wire with alligator clips on both
ends and clamp one end on the metal fitting exiting the rotary pump and the
other end to the airframe. I'm in the desert where static is relatively
easy to generate, but so far with using it over several years no problem. I
have seen sparks generated fueling directly from a plastic jerry can with no
ground wire. Also no explosion or fire. The spark was above the fuel fumes
sufficiently. It did scare the heck out of me tho.

--
Stu Fields