Just to confirm the use of the "bum line"
The pilot reported that she was making a normal approach to the oil platform. Both cranes were shut down on the oil platform, and she received a green deck for landing. The helicopter was over the landing circle when she turned the helicopter’s tail and felt a severe shudder. She immediately landed and shut down the helicopter. The examination of the helicopter and landing platform revealed that the tail rotor blades had struck a handrail on the east crane davit, which resulted in substantial damage to the tail rotor gearbox and drivetrain.
The National Transportation Safety Board determines the probable cause(s) of this accident to be: The pilot’s failure to maintain tail rotor clearance from a handrail on a crane davit on an oil platform during landing.