Report on the serious aircraft incident 12 August 2014 at Rørvik Airport, Norway, with Airbus Helicopters EC 130 B4, LN-ORR, operated by Helicopter Utleie AS
The helicopter was about to land at Rørvik Airport for refuelling. There were two people on board, the commander and loadmaster. Uncontrolled rotation to the left started as the helicopter passed runway treshold at an altitude of 5-10 metres. The commander quickly understood that he had no directional control, and chose to land the helicopter without engine power. The helicopter rotated twice around its own axis before it was landed on the runway. No injuries or damage occurred. After landing, it was quickly discovered that there was no mechanical connection between the fenestron (tail rotor) and the engine's reduction gearbox. A technical investigation revealed that the tail rotor shaft had fractured due to incorrect installation of the tail rotor shaft bearing no. 1. The incorrect installation led to cyclic loads in the tail rotor shaft, which eventually caused a fracture. The bearings on the tail rotor shaft were replaced in connection with scheduled maintenance 98 flying hours prior to the incident.
Since an incorrect installation of bearing no. 1 caused the fracture, further investigations were conducted both in the helicopter company's Part M organisation and in the maintenance organisation that delivers maintenance services to the helicopter company. The investigations identified a number of deficiencies in connection with planning of maintenance, routines for systematic control of critical maintenance activities, as well as routines for maintaining technical personnel's competence.
|Location||Rørvik Airport, Norway|
|ICAO Location indicator||ENRM|
|Aircraft||Airbus Helicopters EC130B4|
|Type of occurrence||Serious incident|
|Type of operation||Commercial, other|
|Category of operation||Heavy, helicopter (> 2 250kg)|
|Aircraft category||Helicopter, Single-engine|
|FIR/AOR||ENOB (Bodø FIC/OFIR)|