When have you heard of lightning striking an aircraft?
Jet aircraft get hit all the time by lightning. They are designed to take it. A pilot at Air Canada told me he was in an A320 that was hit by lightning - not even a flicker on the CRT displays.
In terms of "grounded objects", an a/c may be grounded relative to the electrical charge (negative charge) in the atmosphere and thus receive a lightning strike. The opposite may also occur when the a/c has a surplus of electrons (negative charge) relative to the local atmosphere and the lightning would then go from the plane to the sky which would have a positve charge
In terms of flying a chopper near lightning, I will defintiely pass on that one.