K48
Its hard to know what caused my strike when there was no updraft etc. I can only assume it was left over from earlier cumuliform activity - the cloud had evaporated but the electric charge remained lurking until I was stupid enough to fly by! It was not a particularly bad strike, though 1 rotor blade had to be replaced.
In the hangar, at first it did not look as though the blades were damaged but standing on a ladder and sniffing the end of each blade, the damaged one had a very marked smell of burning plastic and sure enough the leading edge/bonding strip had been pushed up a bit by boiling plastic inside, at the junction between 2 strips where I guess there was relatively high resistance.
Whether this could occur onshore I don't know. The mechanisms tend to be slightly different onshore - as PKPF says the trigger offshore in winter is the warm sea (I use that term relatively!) whereas onshore it tends to be sun warming ground. In other words onshore lightning occurs in summer when 0C is well above your cruising altitude, whereas in winter offshore its at normal heli cruising altitudes.
HughM's policy of going low when there is a risk of lightning is one I also subscribe to (since I was struck!) and I think the primary reason why it is sucessful is because you are then well below the 0C altitude (low level air being "warmed" by the sea)
HC