The 2013 CHC Helicopter Eurocopter AS332 crash involved a Eurocopter AS332L2 Super Puma Mk 2 (G-WNSB) belonging to CHC Helicopters that crashed into the sea 2 nm from Sumburgh in the Shetland Islands, Scotland while en route from Borgsten Dolphin oil platform. The accident killed four of the passengers; 12 other passengers and two crew were rescued. An investigation by the UK’s Air Accident Investigation Branch is ongoing.
The flight took off from Aberdeen Airport and stopped at two oil rigs to pick up passengers. Landing first on the Total North Alwyn Platform before flying the short distance to the Borgsten Dolphin; alongside the Dunbar platform as an accommodation tender. After taking off the helicopter was destined to land at Sumburgh Airport to refuel before flying on to Aberdeen Airport.
The weather conditions were a light breeze (17 knots) with mist.
The helicopter was on an otherwise normal approach to Sumburgh Airport, when at 18:17–18:20 local time, the aircraft lost contact with air traffic control. No mayday was sent out by the pilots as they attempted to make a controlled ditching into the North Sea, 1.5-2 nm west from Sumburgh. The helicopter fell into the sea and then turned upside down during the evacuation. The helicopter was found broken into several pieces up against rocks at Fitful Head.
Recovered flight data noted by the Air Accident Investigation Branch suggests that the helicopter engines remained powered until impact. The manufacturer’s initial analysis based on that data indicated that a combination of factors had placed the helicopter into a vortex ring state at low altitude which made impact “unavoidable”.
The Lerwick Royal National Lifeboat Institution lifeboat, the Sumburgh based Coastguard helicopter and an RAF helicopter from RAF Lossiemouth were sent to find the downed helicopter. Two helicopters from Bond Offshore Helicopters, the passenger ferry MS Hjaltland and a cargo ship, the MS Helliar also joined in the search. The helicopter was found;12 passengers and two crew were rescued and sent to Gilbert Bain Hospital in Lerwick, Shetland Islands. One of the rescued passengers died from their injuries whilst being transported to the hospital.
Two bodies were found inside the aircraft and another was recovered later from the wreckage.
The Police Scotland and Air Accidents Investigation Branch have launched an investigation into the cause of the accident. On 5 September 2013, the Air Accidents Investigation Branch special bulletin reported that there is no evidence of a causal technical failure that could have led to the crash. Both the wreckage and black boxes are still being examined.
A day after the accident CHC helicopter temporarily suspended all Super Puma L2 flights worldwide. The Helicopter Safety Steering Group said that all four different models of the Super Puma should be ground over safety concerns. On 10 September 2013, the Transport Select Committee began an inquiry into the safety of offshore helicopters in the North Sea.