Rotorcraft
Fatigue Fracture Blamed in Fatal EC225 Crash in Norway
Gear Failure Caused Main Rotor Separation In Flight

The fatal April 29, 2016 accident near Norwegian coastal island Turøy that killed all 13 aboard an Airbus Helicopters EC225 LP after its main rotors separated from the helicopter in flight was the result of “a fatigue fracture in a second stage planet gear in the epicyclic module of the main rotor gearbox," according to a final report issued this morning by the Accident Investigation Board of Norway (AIBN). The board further found "cracks initiated from a micro-pit at the surface and developed subsurface to a catastrophic failure without being detected. There are no connections between the crew handling and the accident. The AIBN has also excluded material unconformity and mechanical failure, as well as maintenance actions by the helicopter operator.” The helicopter was operated by CHC for Statoil.