After an uneventful five-minute flight from one North Sea helideck to another, the Sikorsky S-92A pilot lost yaw control and the helicopter landed heavily on the platform deck, where it turned 180 degrees and stopped at the platform’s edge, according to the final report by the U.K. Air Accidents Investigation Branch (AAIB).
None of the nine passengers and two pilots was injured in the December 28, 2016, event, one of a cluster of accidents and incidents involving helicopters being flown in support of the offshore oil and gas industry.
In its final report, the AAIB cited two causal factors — the tail rotor pitch change shaft (TRPCS) bearing failed for an undetermined reason, and the bearing failure resulted in damage to the TRPCS.
Contributing factors were:
- That the impending failure of the TRPCS bearing was not identified during routine maintenance even though a problem was detected by the health and usage monitoring system (HUMS). “Human performance limitat…
