Civil aviation regulators in Norway and the UK have lifted their flight ban on the Airbus Helicopters H225 and AS332 L2 ending a grounding in the North Sea region that has lasted over a year.

All Super Pumas were pulled from service following a fatal accident on Norway’s west coast on 29 April 2016 in which 13 people were killed.

European regulators banned the type in early June based on safety concerns raised by Norwegian investigators.

Although that restriction was relaxed in October 2016, grounding orders remained in place in Norway and the UK, effectively discounting Super Pumas from one of the offshore industry’s key regions.

But the UK Civil Aviation Authority (CAA) says its decision to rescind the ban follows “extensive investigation, testing and changes to the helicopter and its maintenance” which have resulted in “enhanced safety measures”.

However, it notes that “flights will not resume immediately” and each operator will be required to submit a “safety case” proving they have all the necessary processes, training and equipment in place.

It adds: “It will also be for operators and their customers to decide whether they wish to re-introduce the helicopters to service.”

With the oil and gas sector mired in a continuing downturn, it is doubtful if the Super Puma fleet will be immediately acquired, with the Sikorsky S-92 and super-medium types such as the AgustaWestland AW189 having proved capable replacements.

In addition, the offshore workforce will have to be convinced that the H225 and AS332 L2 are safe to fly in; suspicion of the type had emerged prior to the 2016 crash following a pair of ditchings in 2012, and another fatal accident in 2013.

Changes made to the Super Puma by Airbus Helicopters include: the removal from service of one of the two versions of the second-stage plant gear that failed in the Norwegian crash; earlier replacement of gearbox parts; shorter inspection intervals; and a lowering of replacement thresholds.

John McColl, head of airworthiness at the UK CAA, says: “This is not a decision we have taken lightly. It has only been made after receiving extensive information from the Norwegian accident investigators and being satisfied with the subsequent changes introduced by Airbus Helicopters through detailed assessment and analysis.

“We would not have made this decision unless we were convinced that the changes to the helicopters and their maintenance restore the required airworthiness standards.”

While expressing “deep regret” for the 2016 accident, Airbus Helicopters says it welcomes the lifting of the flight ban, but adds: “We understand that this will not necessarily result in immediate passenger flights as there is a lot of work to be done to restore confidence in the aircraft.”