The sobering images of wreckage floating in the waters off the Shetland Islands are a stark reminder of the dangers faced by offshore oil workers traveling by helicopter.

But the deaths of four workers following the crash of a CHC Scotia-operated Eurocopter AS332L2 Super Puma on Aug. 23 have sparked an unprecedented public outcry that could end up having a dramatic effect on both the oil and gas industry and the helicopter operators that support it.

While the flight suspension for the AS332L2 model and other variants of the Super Puma has now been lifted, almost 40,000 people have given their support to a social media campaign dubbed “Destroy the Super Pumas” set up within hours of the tragedy, calling for the removal of the aircraft and its variants from operational service in the North Sea.

The Facebook page says oil workers are fearful of flying in the type after the fifth accident involving the helicopter in four years. Two of those accidents have claimed a total of 20 lives.

Oil executives are concerned that if the campaign gains traction, the move could result in widespread disruption of oil production in the North Sea, as well as the industries that support it.

In line with a request from the Helicopter Safety Steering Group (HSSG)—a committee formed in response to previous North Sea helicopter accidents—CHC, Bond Offshore Helicopters and the Bristow Group halted operations with the Eurocopter AS322L2 and other Super Puma variants in the U.K., including the older AS332L/L1 models and the more modern EC225, within hours of the accident.

The EC225 had been just returning to service after a nine-month halt from flight operations over water following problems with the bevel gear vertical shaft in the main gearbox.

The flight suspension on all four rotorcraft variants was eventually lifted Aug. 29 following a two-day meeting of the HSSG. However, the group says that, given the sensitivities around the accident, the AS332L2 should only initially return to non-revenue operations such as training.

The HSSG says it is “satisfied that there is no reason to believe there is an inherent mechanical problem with any of the AS332L/L1, AS332L2 or EC225 helicopter types.” CHC, which returned AS332L2s to operations outside the U.K. Aug 29, says: “From what we know so far about the Sumburgh incident, as well as tens of thousands of hours of experience with this aircraft, it is apparent there is not a fundamental problem with AS332L2 aircraft that led to this accident.”

But workers unions remain dissatisfied, saying that “workforce confidence in the Super Puma type aircraft was severely dented after the two ditching events of last year and the fatal accident in 2009.” They urge that the helicopters not restart operations until the cause of the Aug. 23 accident is found.

Operators and the British Airline Pilots Association (Balpa) have reaffirmed their confidence in the rotorcraft, urging oil workers not to judge it or draw early conclusions about the accident, since investigators have not yet reported the cause.

Twelve passengers and the two pilots managed to escape from the Super Puma within minutes after it ditched into the misty waters off Fitful Head at the southern tip of the Shetland Islands. The helicopter, registered as G-WNSB, was just minutes from landing at Sumburgh Airport after flying from the drilling platform Borgsten Dolphin on behalf of the oil firm Total when it apparently suffered a catastrophic loss of power, sending it tumbling into the sea.

Investigators say the approach to Sumburgh appeared normal until 3 mi. out, when the airspeed decreased and the helicopter descended rapidly. They believe the rotorcraft landed intact and upright, but rolled over in the water and was broken up by repeated contact with the rocky shoreline.

Within hours, emergency services recovered three bodies; a fourth was reportedly found still trapped within the helicopter's cabin. The wreckage of the rotorcraft has since been salvaged and brought aboard an oil and gas support ship, Bibby Polaris. The flight data recorder was found on Aug. 29.

Since the accident, Total has reportedly chartered several ships to conduct platform-crew change operations with the expectation that some workers will refuse to fly to platforms on any model of helicopter. Other companies extended staff rotation periods on platforms and reduced manning to minimum levels. Of the 16,000 people offshore at any one time, some 12,000 were affected by the disruption caused by the suspension.

Using ships is not a long-term solution: While helicopter transfer missions take just a couple of hours, ship transfers can take up to 10 times as long, and transiting passengers from vessel to platform presents its own dangers.

Some in the support-helicopter industry believe the HSSG may well have been backed into a corner by the workers unions. By calling for the grounding of all Super Puma variants, the HSSG inadvertently associated the crashed AS332L2 model with the EC225, even though the two types are distinctly different in terms of operation and engineering. The EC225 was only grounded after investigators linked the two incidents in May and October 2012, neither of which resulted in any fatalities (AW&ST July 22, p. 51).

Only a handful of the EC225s operating from Aberdeen—the main base of the North Sea helicopter companies—have returned to operations since interim fixes were certified in July. Some of the larger oil companies have been consulting with the operators to ensure they have the capabilities to conduct the interim procedures mandated by regulators for potentially up to two years, as Eurocopter works on a permanent fix to the issue.

“There is a need to arm workers with the facts about these aircraft,” says one helicopter operator executive. “But not all the oil companies realize this.”

Oil companies and the helicopter operators fear a ripple effect not just across the North Sea, but in other areas of the world where helicopters are relied on for crew-change missions. Eurocopter, which in the days after the accident sent top executives including new CEO Guillaume Faury to Aberdeen, has been quick to point out that the AS332L2 involved in the accident was equipped with a main gearbox with a carburized vertical shaft, not a nitrided (hardened) shaft, like the one involved in the two EC225 ditchings.

Operators, trade unions and regulators will engage with the offshore workforce to “rebuild trust and confidence,” and a “sympathetic” approach will be taken with any worker who feels unable to fly, the HSSG says.