Offshore workers are disappointed and frustrated at the lack of information about what caused a helicopter to ditch in the sea near Shetland, a union leader has said.
All 19 people on the CHC-operated aircraft were rescued by the crew of a nearby ship and then flown to land after the incident on Monday.
The ditched helicopter was salvaged and arrived at Peterhead harbour on the Aberdeenshire coast early this morning.
The Air Accidents Investigation Branch (AAIB) has begun an inquiry into why the pilot had to ditch.
CHC and two other offshore helicopter companies, Bond and Bristow, have now suspended their use of the Super Puma EC225 model.
A meeting of the Helicopter Safety Steering Group, made up of representatives of operators, oil companies and unions, was held in Aberdeen but the cause of the ditching was not discussed.
RMT offshore organiser Jake Molloy said: "The operator CHC and the others are unable to provide any information about the causes of the ditching because they are bound by the protocols of AAIB, which dictate you cannot discuss findings until their investigation has concluded. So we await that to be wound up, which could be done by tonight or in the next few days.
"It's frustrating and disappointing for workers as it means we are not in a position to discuss the way forward. Many of the workforce will be extremely frustrated as some will be stuck offshore or alternatively stuck onshore, some of them perhaps not being paid.
"But I would hope that the frustration the guys are feeling will be tempered by the fact that the decision to suspend flights has been done in their best interests, and we are looking to prevent a recurrence of Monday's event.
"I hope they understand that, and I hope AAIB conclude their investigations quickly and perhaps get things at least in part back to normal."
The helicopter was carrying an oil crew from Aberdeen to a rig 86 miles (138.4km) north-west of Shetland when it ditched at around 3.30pm on Monday. The 17 passengers and two crew were taken off their life raft by a rescue boat launched from the Nord Nightingale tanker which was close to the scene.
They were taken back to the tanker and then flown to Kirkwall in Orkney by RAF and Bond rescue helicopters.
The ditching is the fourth serious helicopter incident in three years.
In May, all 14 passengers and crew members on a Super Puma helicopter were rescued when it ditched about 30 miles (48.3km) off the coast of Aberdeen. It was on a scheduled flight from Aberdeen Airport to a platform in the North Sea.
On April 1 2009, 16 people died when a Super Puma crashed into the sea off the Aberdeenshire coast. The gearbox of the Bond-operated helicopter failed as it was returning from the BP Miller platform.
About six weeks earlier, another Bond Super Puma with 18 people on board ditched in the North Sea as it approached a production platform owned by BP. Everyone survived the incident.
Eurocopter did not comment on reports that the crew indicated a possible problem with the aircraft's gearbox in the latest incident.
Mr Molloy said: "It's been rumoured it was another gearbox issue and that is a major concern because that would be the third issue with this aircraft-type gearbox in the last few years.
"There's no certainty that it is the gearbox and the gearbox is a complex piece of kit so it could be a separate component in it that caused the problem.
"We could speculate until the cows come home over what caused it but there really is no point. We really need a definite finding from AAIB so that we in turn can determine how to move forward."
Eurocopter said it will make a statement on the EC225 model in the next few days, based on the early findings of the investigation.
Senior customer support director Jean-Pierre Dedieu said the BEA, the French authority responsible for safety investigations into air incidents, was involved along with the AAIB.
"They are going to inspect the helicopter before dismantling some components for analysis in the laboratory," he said.