What happened
On the night of October 31, 2021, a Sikorsky S-92A helicopter, registration LN-ONH, operated by Bristow Norway AS, was conducting a Search and Rescue (SAR) training mission near the Ekofisk Lima platform. The flight was a line check intended to renew the pilot's SAR captain privileges. The mission involved hoisting a rescue technician from the deck of the supply vessel Skandi Hugen.
During the operation, the helicopter approached the vessel in heavy weather, characterized by winds of 45–50 knots and significant wave heights of over 4 meters. As the rescue technician was being lowered, the helicopter experienced a slight forward deviation, causing the technician to swing. To avoid a collision with the ship's structure, the technician attempted to land on a section of the deck. However, as the vessel was struck by a large wave, the stern was lifted, causing the technician to fall approximately 2.5 meters onto the deck. The impact resulted in broken bones and a punctured lung, requiring a five-day hospitalization.
The investigation
The Norwegian Safety Investigation Authority (NSIA) examined the operational conditions, the equipment used, and the training protocols in place. The investigation focused on the visibility during the night operation, the capabilities of the aircraft's lighting, and the environmental factors, such as the heavy sea state and wind. Investigators also reviewed the training requirements for maintaining SAR privileges and the availability of safety equipment, such as safety boats and helmet cameras, during the training exercise.
Findings
- The primary cause of the injury was the sudden movement of the vessel caused by a wave, which led to the technician's fall.
- The helicopter used was a simplified SAR version, which lacked the powerful side-lighting found on fully equipped SAR aircraft, potentially making it harder to identify a calm wave period.
- The rescue technician was wearing a life vest with a manual inflation system that lacked additional buoyancy elements.
- There was no safety boat present during this specific training evolution, though its use was not mandatory for this type of single-person hoist.
- The use of helmet cameras, which could provide valuable footage for post-mission evaluation, was not utilized during this flight.
Safety action
- The NSIA suggests that a forum for exchanging safety experiences between different offshore SAR operators would be beneficial.
- The investigation noted that using a fully equipped SAR helicopter might have reduced the risk of such an occurrence by providing better visibility of the sea surface.
- The use of helmet cameras by hoist operators and rescue technicians is recommended to enhance safety evaluations and mission documentation.