Thanks Colibri - I understand the equalisation of the potentials, it's the apparent difference between refueling cars and aircraft I'm trying to grasp. From the additional replies and further research, it seems most likely that:
- cars have inbuilt mechanisms to equalise any difference between potential, by protecting the fuel tank until the car's metal has touched the fuel nozzle and therefore equalised any difference - thanks also for that Crash One, I didn't know either.
- cars are in constant contact with the ground and therefore can constantly dissipate any static, albeit very slowly, through the tires whereas in aircraft it builds and may not be dissipated by the time you arrive at the fuel pump.
- static buildup in aircraft is greater due to speeds involved
- static buildup in fuel lines is greater due to volumes involved.
Would this be a fair summary?
I'm still not grasping the difference between bonded and grounded though. I always thought grounding was giving electricity a route to earth. And I then assumed that bonding was tying two bodies together to equalise them, which may or may not involve grounding them (so two hypothetical planes connected in the air by a cable and clips would be bonded but not grounded). Am I way off here?