In Nov 1980 a newly transferred pilot from 76s managed to cut half way through the hand rail on the Sedco 707's drill tower with a 61 tail rotor; classically he had forgotten he was flying a larger aircraft and used the 76 landing circle. The only indication of damage was a high frequency buzz through the yaw pedals.
I went out the next day and managed to put a 61 on the extended keyhole deck of the rig, rather than winch the engineers and replacement crew down. The damage to the hand rail was amazing, the tail rotor blades had lost a few inches.
Above the noise of the aircraft I had a fascinating 'discussion' with the pilot concerned explaining how he was returning in the cabin with me and not, definitely not, returning in the aircraft he had just maimed.