To: NickLappos
See the picture of the Black hawk above. It HAS all the bonding you could ask for. It is on the ground, statically grounded to the earth. Yet it shows the "corona"
One answer to your question is that the static charge is building at a rate faster than it can be dissipated.
On a cargo pick-up or drop off the man on the ground has to ground the static charge on the airframe and he must maintain the ground. If he doesn't and he touches the cargo hook he can get knocked on his ass. The same is true when making a hoist pick-up over water. The winch cable must be dipped in the water to drain the charge. If the pilot lifts the helicopter up a bit in the hover and the hoist cable comes out of the water and the person in the water touches the cable he can be rendered unconscious. That is how fast the charge can be built up. In the case of the Blackhawk in the picture I can assume the grounding cable was on dry earth with minimal conductivity allowing the charge to build up.
Now, I have answered your question (right or wrong) I would like you to comment about the torroidal magnetic field around the 214 and the AH-1J
