April of 2016 an Airbus H225 "Super Puma" Operating as “CHC Helikopter Service Flight 241”, the Airbus H225 was carrying oil workers from the Gullfaks B platform in the North Sea when the main rotor separated in flight. The Airbus H225 crashed near Turøy, a Norwegian coastal island 36 kilometres (22 mi) from the city of Bergen. The outcome, all 13 Souls on board were lost.
Video of the main rotor separation
The Accident Investigation Board of Norway (AIBN) has called on Airbus Helicopters to revise the type design of the AS332 L2 and H225/EC225 LP, as part of its far-reaching final report into a fatal crash of a Super Puma near Turoy, Norway, in April 2016.
The recommendation to “improve the robustness, reliability and safety of the main gearbox” in the two Super Puma variants was one of 12 safety recommendations in the report. It also targets the European Aviation Safety Agency (EASA), calling on the regulator to revise certification standards for large rotorcraft, commission research into crack development in certain aircraft bearings, and make sure manufacturers’ continuing airworthiness programs cover the examination of critical components found to be beyond serviceable limits.
The cause of the accident, which killed all 13 people on board, was a fatigue fracture in one of eight second stage planet gears in the epicyclic module of the main rotor gearbox, the AIBN report found. This ultimately caused the aircraft’s gearbox to seize and rupture, leading to the detachment of the main rotor.
It took 13 seconds from the time of Main Rotor separation for the ship to crash.
(The part of the helicopter that failed which resulted in the Main Rotor separation)
Here is Airbus’ investigation video