Fatal Super Puma accident 'similar' to Peterhead crash
Thirteen people – including a Scottish oil worker – died in the helicopter crash in Norway.
The cause of a helicopter crash which claimed the lives of 13 people - including a Scottish oil worker - has been revealed.
Iain Stuart, from Aberdeenshire, was among those killed when a Super Puma crashed into an island off the coast of Norway in April 2016.
A two-year inquiry has now confirmed long-held suspicions that the crash was a result of a gearbox failure which caused the helicopter's rotor to detach.
It separated without warning, causing the aircraft to fall 2000ft to the ground and burst into flames.
The accident had "clear similarities" to a 2009 Super Puma crash near Peterhead which killed 16 people, according to the Accident Investigation Board Norway (AIBN).
In both cases the main rotors detached from the helicopters as a result of a fatigue fracture in a planet gear in the main gearbox.
Senior AIBN adviser Ingvild Ytrehus said: "Following the accident in 2009 the actions taken by the European Aviation Safety Agency and Airbus Helicopters were not sufficient to prevent another main rotor loss."
The fatigue fracture which caused the Norway accident developed in a way which was unlikely to have been discovered during routine maintenance, the AIBN said.
It concluded there are "significant lessons to be learned" about gearbox design and the airworthiness of Super Puma helicopters.
The AIBN has made 12 safety recommendations as a result.
A spokesman for Super Puma manufacturers Airbus acknowledged the similarities to the 2009 crash but said the Norway accident would have been "impossible" to prevent.
"Neither aviation authorities nor the industry had ever seen the type of crack in the main gear box which led to the accident," they said.
"Extensive analysis of the accident has led to the development of safety measures which have allowed the H225 [known as the Super Puma before a 2015 rebrand] fleet to resume flight operations worldwide.
"However, no H225s are flying in the North Sea today and we understand there are no immediate requirements for these aircraft in the North Sea."