Bristow Helicopters (Nig) Ltd. final-report accident CIA 161

The accident occurred towards the end of the day’s sorties and it was the turn of the co-pilot to fly the last segment of ASABO-BOP-IDOHO-EKET. Departure from the Oil-Rig ASABO to BOP was normal until descent to the BOP platform.
At the beginning of the descent from 700 feet the F/O was still flying, until they heard a bang noise accompanied by a yaw to the right hand side and the captain quickly took over the control from his co-pilot. The captain said that he thought they had a tail rotor failure so he started to apply corrective measures for a tail-rotor disability.