What happened
On 14 November 1993, an incident occurred involving a Bell 212 helicopter, registration ZK-HNO, during a maritime recovery operation. The aircraft was engaged in winching personnel from the ship Pacific Ariki, which was positioned approximately 2nm west of Oaonui. During the process of being hoisted from the vessel, two persons fell from the hoist.
The investigation
The investigation focused on the mechanics of the winching process and the safety protocols in place at the time of the accident. Investigators examined the functionality of the aircraft's hoist, the integrity of the winch cable, and the electrical design of the hoist control circuitry. Furthermore, the inquiry looked into the oversight provided by the Civil Aviation Authority (CAA) regarding operator approvals and the quality of safety audits conducted on the operator.
Findings
The investigation identified several contributing factors to the fall. A primary concern was the dependence of the hoist design on the integrity of the winch cable, as the system's safety relied heavily on the cable remaining intact. Additionally, investigators found that existing instructions regarding winch operations were inadequate. The inquiry also highlighted deficiencies in crew training and supervision, noting that the crew did not fully comply with established instructions. Finally, the investigation noted that current inspection techniques were insufficient for accurately determining the serviceability of the winch cable.