Eurocopter AS355 F1, ZK-IAV, spherical thrust bearing failure
and subsequent severe vibration and forced landing, Mount Victoria, Wellington, 13 April 2008
and subsequent severe vibration and forced landing, Mount Victoria, Wellington, 13 April 2008
Status
Closed
Occurrence Date
Report Publication Date
Jurisdiction
NZ
Legacy Inquiry Number
08-002
At 1112 on Sunday 13 April 2008, ZK-IAV, a Eurocopter AS355 helicopter, departed from Wellington International Airport on a visual flight rules flight to Marlborough Sounds, with the pilot and one passenger on board.
Two minutes after departure, one of the 3 main rotor blade spherical thrust bearings attached to the rotor head failed. The failure caused a significant main rotor loss of balance and track, which resulted in severe vibration and limited the pilot’s ability to control the helicopter. Despite the vibration and limited control, the pilot completed a successful emergency landing in a nearby sports field with no injuries.
The bearing failed because of internal corrosion and de-bonding of its elastomer segment, which was probably a result of some undetected surface damage to the elastomer surface.
Safety issues identified included the old age of the bearings, the adequacy of inspections and the bearings continued use without a specified calendar life. Safety recommendations were made to the Director of Civil Aviation to address these safety issues.
Two minutes after departure, one of the 3 main rotor blade spherical thrust bearings attached to the rotor head failed. The failure caused a significant main rotor loss of balance and track, which resulted in severe vibration and limited the pilot’s ability to control the helicopter. Despite the vibration and limited control, the pilot completed a successful emergency landing in a nearby sports field with no injuries.
The bearing failed because of internal corrosion and de-bonding of its elastomer segment, which was probably a result of some undetected surface damage to the elastomer surface.
Safety issues identified included the old age of the bearings, the adequacy of inspections and the bearings continued use without a specified calendar life. Safety recommendations were made to the Director of Civil Aviation to address these safety issues.
Location
Newtown, Wellington (-41.306694,174.784021) [may be approximate]