Investigators are continuing to search for the black box data recorder of a helicopter that plunged into the North Sea, killing four oil workers.
Salvage experts at the site of the crash have been using specialist sonar equipment to try to trace the device, which was located in the tail section of the aircraft.
It is hoped information on the flight recorder will help establish what caused the CHC-operated Super Puma AS332 L2 to ditch as it approached Sumburgh airport on the southern tip of Shetland on Friday evening.
Once traced, the recorder will be transported to the headquarters of the Air Accidents Investigation Branch at Farnborough, Hampshire, for examination.
Duncan Trapp, vice president for safety and quality at CHC Helicopter, said the crash would be “painstakingly investigated” to find out what went wrong.
“The Air Accidents Investigation Branch (AAIB) will be reviewing information including debriefs with pilots and passengers, air traffic records, technical data and records, and the aircraft and its on-board systems,” he said.
“We are fully supporting the early stages of the investigation into the incident and will continue to give our full co-operation to this process.”
The pilot of the helicopter is recovering in hospital with back injuries, while the co-pilot is recuperating at home, he said.
CHC grounded the model involved in the crash and suspended all UK flights of three other Super Puma types.
Fellow operators Bond Offshore Helicopters and Bristow also enforced a temporary suspension of all Super Puma flights except emergency rescue missions.
It follows a recommendation by the offshore industry’s Helicopter Safety Steering Group (HSSG) which urged the precautionary measure until there is “sufficient factual information” to resume flights.
Around 80 representatives of oil and gas operators and major contractors attended a “sombre” meeting in Aberdeen yesterday to discuss contingency plans following the suspension.
Oil & Gas UK chief executive Malcolm Webb said the summit had endorsed the HSSG’s recommendation.
Options being considered to ease the problem of flight delays and backlogs include the use of alternative helicopters, making better use of available flights and the possibility of transferring workers by boat.
Mr Trapp said he understood that emotions in the offshore workforce were “raw” after the crash.
“There has been a huge amount of work by everyone involved in safety in the offshore oil-and-gas industry to mitigate the risks of working in and travelling to offshore installations,” he said.
“Consultation and collaboration between helicopter operators, the oil and gas companies and the unions representing pilots and offshore workforce has led to technical advances, improved predictability and the mitigation of the risks flying in the North Sea presents.
“My message and commitment to offshore workers and everyone with an interest in our industry is that we will continue to do everything humanly possible to ensure we get them to work and get home safely every time.”
The Unite union has called for an emergency debate on offshore health and safety when the Scottish Parliament reconvenes next week.
It also urged the Scottish Government to support the fast-track of Fatal Accident Inquiry (FAI) reforms, which are currently under public consultation.
Scottish secretary Pat Rafferty said: “On Thursday we vented our anger over the current FAI process and the ridiculous delays in starting the FAI into the 2009 Super Puma crash, the agony this is causing victim’s families and the fact that we do not have legally enforceable outcomes from the process.
“This will be of no comfort to the families impacted by Friday’s catastrophe but we need these reforms to our civil justice system in Scotland and we need them now.”
There have been five North Sea incidents involving Super Pumas since 2009. In April that year an AS332 L2, operated by Bond, went down north-east of Peterhead on its return from a BP platform, killing all 14 passengers and two crew on board.
The other three ditchings involved the EC225 model which saw flights temporarily suspended. CHC returned the model to commercial service only earlier this month.
An investigation by the Air Accidents Investigation Branch found that two of the incidents were the result of gearbox failure and new advice on checks for the EC225 were issued as a result. A fatal accident inquiry is expected to be held into the 2009 fatal AS332 L2 crash in Aberdeen next year.