Eurocopter anticipates that a solution to the main gearbox problem that has grounded the North Sea fleet of EC225s will be available next month. Offshore operators, especially those in the North Sea, have seen major disruption of their activities, as have the oil and gas companies that depend on helicopter transportation for crew changes on their platforms.

Last month Eurocopter invited a delegation representing the Helicopter Safety Steering Group (linked to lobbying association Oil and Gas UK) to its manufacturing and test facility at Marignane, France, to show oil and gas company representatives what it is doing to trace the origin of the problem and fix it.

While Eurocopter engineers have found the root cause and developed a fix for false alarms with the main-gearbox emergency lubrication system, sleuthing the shaft cracks has been trickier. Despite extensive bench- and flight-testing, “We have not been able to reproduce the failure so far,” CEO Lutz Bertling conceded in late January. An interim workaround could build on the one already in place. It is based on thorough monitoring of certain Hums (helicopter usage and monitoring system) parameters, such as vibration. A shaft redesign, if needed, would take about a year-and-a-half, Bristow officials estimated during a teleconference early last month.

Norwegian and UK authorities continue to prohibit flights over water, a measure that has clipped the rotary wings of 25 EC225s. Bristow has suspended operations of 16 EC225s–12 in the UK, three in Australia and one in Norway. Other major offshore operators are also feeling the effect of the grounding. CHC has 30 EC225s out of service. Bond declined to give a precise number but AIN understands it is in the single digits.

According to Eurocopter, 35 EC225s are flying, having implemented the emergency service bulletin’s requirements. All EC725s (the military version of the EC225) are flying. Bristow officials estimate that about 80 aircraft have been suspended from flying worldwide.

In fact, after the British and Norwegian authorities decided to ground EC225s used for overwater flights, other countries followed suit. According to Olivier Claeys, an aviation expert at oil company Total, operators (as opposed to aviation authorities, Bristow officials noted) suspended EC225 flights worldwide. EC225s serving Total oil platforms in Angola, for example, are grounded.

Eurocopter says it has “more than 100 employees” working full time and directly on identifying the cause of the failure, implementing retrofits and so on. An external firm, Shainin Engineering, is contributing to the effort with “methodological and technical support” in the research process. Plugging the Gaps

Bristow executives say they have reacted in several ways. “To mitigate the impact of this suspension on our clients, we have increased utilization of other in-region aircraft and implemented contingency plans designed to return to service previously stored Eurocopter AS332Ls,” the company wrote in a statement.

Furthermore, it says that its order for Sikorsky S-92s, announced in November–15 days after the second EC225 ditching last year–was in response to the EC225 grounding. The first of the 10 S-92s on firm order is slated for delivery in the middle of this year.

Simulators are easing the transition to aircraft other than the EC225, Bristow officials said, and customers are helping out by maintaining minimum staffing on the platforms.

To restore the capacity lost to the grounding of 30 aircraft, CHC is using other types, a spokeswoman told AIN. She confirmed Eurocopter has provided replacement components and gearboxes so operators can return AS332L/L2/L1 Super Pumas to service. “Eurocopter has also given our experts access to [updated] information and detailed technical data,” she said. Flying seven days a week has become commonplace again among offshore North Sea operators.

As another mitigation measure for crew changes, oil companies are sharing available space in helicopters. “Each of the oil companies informs others in the geographical area if they have any spare seats on their flights and tries to ensure any spare capacity is used,” said Jake Molloy, regional organizer for the RMT union of workers.

Some workers have suffered delays to and from the platforms. Weather permitting, boats have supplemented the helicopters, Molloy said. Claeys added that boat transfer has been minimal for Total employees.

“In some extreme cases workers have been made redundant as planned projects have been delayed or cancelled, but thankfully this seems to be a relatively small number,” Molloy said.

By early February, crew change delays had been eliminated, Claeys said. In 2011, Total workers accounted for 39,000 passengers at Aberdeen heliport.

Compensation for operators remains a question. A Eurocopter spokesperson declined to say whether it would reimburse the operators, citing “confidential commercial relationships.”

“In certain instances we are not receiving payment for the monthly standing charges in a timely manner, and we are in discussions with our clients regarding these charges,” Bristow said. Company lawyers believe it is “a contractual right to continue to receive the monthly standing charges billed to our clients.”