I was aboard a Kiwi B727 going from ORD to LGA in the summer of about 1996 and as we were climbing there was a very loud "bang". Of course this startled many of the passengers including myself, but I didn't notice any change in engine thrust, so I figured it wasn't anything major. The captain came on the PA and assured us that it was nothing to worry about and that he'd explain what had happened when we reached our cruising altitude, at which time he explained that we had experienced a "static discharge".
1) Is a static discharge similar to a lightning strike?
2) How common are they?
3) If they're uncommon, has anyone else on this forum experienced one?