Airbus has told helicopter operators to carry out rigorous checks on aircraft gearboxes following last year’s fatal crash in Norway.
The order covers the SA365, AS365 and H155 models, about four of which operate in the North Sea.
An Airbus spokesman said the company was being proactive in implementing the safety measures.
The spokesman said there had not been any incidents involving the helicopters covered by the directive and that the majority of the fleet would not be affected.
He said the checks had been ordered as a result of the investigation into the accident in April 2016 involving a Super Puma 225 helicopter.
Thirteen people were killed when the 225 crashed on a return journey from Statoil’s Gullfaks B platform to Bergen Airport.
Iain Stuart, a 41-year-old from Laurencekirk, was among those who died.
Super Pumas have been grounded in the UK and Norway since last year’s crash.
Preliminary investigations have shown that the aircraft’s rotor broke off due to a “fatigue fracture” in one of it gears, but a root cause has yet to be found.
Accident Investigation Board Norway said in April 2017 that it still did not know why a crack in one of the cogs had continued to spread inside the component.
Europe’s aviation watchdog, which issued its own airworthiness directive today, said investigations had shown that one type of planet gear was more susceptible to cracking and had been permanently removed from service to ensure the safe operation of 225s.
The European Aviation Safety Agency said Airbus had reviewed its entire fleet and had decided to “implement precautionary measures” on SA365s, AS365s and H155s to “improve the reliability” of the installed main gearbox.
Operators have to carry out “repetitive inspections” of the “magnetic plugs” in the main gearbox and replace the planet gear assemblies where necessary.
The checks must be undertaken within 10 flight hours of the effective date of the directive, June 16, and during inspections after the last flight each day.