engineno9
Thanks for the replies guys. So as I read it, if I were to answer the question as asked, reasons for aircraft to be bonded/grounded but not cars would be:
- higher volumes of flow for aircraft refueling causing potentially greater static charges in the refueling line
- possibility of aircraft systems being still powered on in larger aircraft
- and tyres don't effectively ground anything (I must admit I thought this too)
Are we saying then that for an aircraft fuel pump fixed to the ground (self-service style for example), the supplied bonding cable earths the plane once attached, but for a fuel truck (also with non-conducting rubber tyres), the truck would be both bonded to the aircraft and then in some way grounded itself? Or are we saying that as long as they're bonded together somehow then no sparks should leap across the gap anyway.
All correct except I think the bit you missing is, a fixed fuelling installation will already be grounded as part of its construction then be bonded with the aircraft via the bonding cable you attach to the airframe.
Are we saying then that for an aircraft fuel pump fixed to the ground (self-service style for example), the supplied bonding cable earths the plane once attached, but for a fuel truck (also with non-conducting rubber tyres), the truck would be both bonded to the aircraft and then in some way grounded itself? Or are we saying that as long as they're bonded together somehow then no sparks should leap across the gap anyway.
You may not have noticed but the fuel truck will normally or should connect to a grounding point via a bonding cable in addition to the bonding cable attached to the aircraft.