Three of four Shetland Super Puma crash victims drowned
Three of the four victims of the Super Puma helicopter crash off Shetland drowned, BBC Scotland has learned.
Death certificates show this was the cause of death for Sarah Darnley, 45, from Elgin, Duncan Munro, 46, from Bishop Auckland, and George Allison, 57, from Winchester.
Gary McCrossan, 59, from Inverness, suffered heart failure.
The latest Air Accidents Investigation Branch (AAIB) report said August's crash was "survivable."
There were 18 people on board the helicopter at the time.
The investigation into the crash is ongoing.
Experts have already recommended that the operator of Sumburgh Airport reviews its water rescue capability.
The AAIB said that of the 10 people to board the two life rafts deployed from the helicopter, one did not survive.
Its bulletin, published on 18 October, revealed that an airport rescue boat had taken nearly an hour to reach the accident site, which was less than two miles from the runway.
A number of other lifeboats and aircraft were sent to the scene, with a Coastguard helicopter the first to arrive, 26 minutes after the accident.
The AAIB said Sumburgh Airport's fast rescue craft had been unable to launch from the slipway nearest the crash site because of an unfavourable tide and "became bogged down" in the sand at an alternative launch site, several miles from the airport.
When the 8.6m rigid inflatable finally made it into the water, two of its three crew members were injured during a seven-mile journey to the scene in rough open seas. They arrived 58 minutes after the accident.
The report found that the slipway nearest the runway was too short, too narrow and "could be used typically in only 11% of tidal conditions".
The alternative launch site was "located on a soft, sand beach" which posed a risk of the launch vehicle "becoming bogged down".
The report concluded: "This accident has highlighted that, in the majority of tidal conditions, the (fast rescue craft) may not be able to respond to aircraft accidents in the sea on the western side of Sumburgh Airport within the available survival time."
The AAIB recommended that the Civil Aviation Authority review the situation and "take appropriate action."
Highlands and Islands Airports Limited (HIAL) managing director Inglis Lyon said: "This was essentially a maritime incident which occurred outside the airport's limited area of responsibility, which is restricted to 1,000 metres.
"As the airport is not a category one responder it plays no formal role in rescue operations beyond the 1,000 metre limit.
"Nevertheless, the airport's fast rescue craft was the first seaborne asset on site, and the team from Sumburgh Airport worked tremendously hard, in extremely difficult circumstances, to support the rescue effort. We owe them, and the other emergency responders, a debt of gratitude for their selfless actions."
He added: "HIAL has taken appropriate action to improve the slipway infrastructure at Sumburgh Airport following earlier recommendations by the AAIB.
"However, it remains the case that Sumburgh Airport's responders were the first to arrive on scene by water and played a crucial role in supporting the emergency response, despite having no formal role in the operation."