The Super Puma, a staple of the offshore oil industry, was grounded for commercial use following the accident in which everyone on board died after the main rotor blades separated from the aircraft.

Analysts and industry executives say questions are growing over the future of at least the civil version of the Super Puma helicopter, which makes up 80% of the programme.

“Of course the product will have a future. We really believe in this product,” Airbus Helicopters chief executive Guillaume Faury told Reuters when asked about the accident, which he described as a shock for the company.

Norwegian investigators have ruled out human error in the crash and have contacted European air safety authorities about a possible safety issue with the helicopter’s gearbox.

“At the moment, we don’t know if this is design, production, maintenance or a combination of the three,” Faury said. “We need to understand, to go to the bottom of the root cause and then solve the problem”.

“Earlier generations of the Super Puma have 5.3 million flight hours over 30 years,” he said in an interview.

Safety experts caution that it is too early to say exactly what caused the helicopter’s rotor blades to detach and send the aircraft plunging onto the rocky coastline off Bergen.

The last such disaster involved an earlier version of Super Puma off Aberdeen in 2009, in which 16 people died.

In 2012, Super Pumas were grounded after two ditchings in the UK North Sea later blamed on gearbox cracks.

“We suspect that the Super Puma brand has been permanently undermined by the accidents, rather as the Chinook was damaged by accidents in the North Sea and was eventually withdrawn from offshore service,”said Agency Partners analysts in a note, referring to a 1986 UK crash which killed 45 oil workers.

Others say Sikorsky, a unit of Lockheed Martin Corp, could benefit from negative publicity surrounding the Airbus Helicopters H225 and Bell Helicopter’s new 525, which crashed during testing earlier this month, killing both test pilots.

Sikorsky this week signed a 10-year agreement to provide extended support to Bristow Helicopters for its S-92 fleet, and a separate 10-year agreement with Babcock Mission Critical Services Ltd, also for the S-92.

“A rebound in oil prices has not been sufficient to boost demand for helicopters in the oil and gas sector, where companies continue to cut costs,” Faury said.

“There is overcapacity in the helicopter sector for supplying the oil and gas and I don’t anticipate that things will change in 2016 and in 2017,” he said.

“Even with a reasonable increase in the oil price, it would take time before investment restarts, Faury said.

“Maybe we have reached the bottom of the crisis as far as the helicopter industry is concerned but I am not speculating that things will rebound quickly.”