Report on helicopter accident at Svanvik, Finnmark county 14 November 2018 with Airbus Helicopters AS 350 B3, LN-OAN operated by Heli-Team AS

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Description

On 14 November 2018 an Airbus Helicopters AS 350 B3 was used for demounting an old mast close to Svanvik, Finnmark county, Norway. During the long-line operation, the main rotor blades hit the new mast which was built a few meters away. A combination of a moment loss of attention of the commander during a critical phase of the flight, and the use of a too short long-line when the next lower section of the mast was to be dismantled led to the incident. Vibration occured in the helicopter. The pilot immediately aborted the operation, and made a precautionary landing nearby. No persons were injured in the incident.

The Accident Investigation Board Norway has classified this incident as a serious aviation incident due to the damage to the rotor blades, and the likelihood that this could become an accident was high. In addition to the commander's exposed position, the AIBN considers that several persons working in the mast were in obvious danger if the rotor blades hitting the three-meter-high spire at the top of the new mast had caused the pilot to loose control of the helicopter.

The Accident investigation Board Norway issues two safety recommendations related to risk assessment and safe job analysis. Both safety recommendations are directed to CAA-Norway.

The damage to the rotor blades showed that they were very close to hitting the spire with their leading edge. If so, it could have resulted in collapse of vital components in the main rotor head "starflex arms" causing a significant imbalance in the main rotor, heavy vibrations and most likely loss of control of the helicopter.

The incident in Svanvik is another example of an incident where the helicopter's main rotor blades came into contact with obstacles which in turn led to an unintended landing.

This type of flight, with a sling load, is considered to be a complex precision operation. Prior to this mission, a secure job analysis was made aiming to address the safety barriers. However, the secure job analysis did not capture that the long line was too short to provide sufficient clearance to the obstacle.

Safety recommendation

Safety recommendation SL no 2019/02T

On Wednesday 14 November 2018, the main rotor of LN-OAN struck the spire on a mast in connection with a nearby mast being dismantled and transported away. This resulted in damage to the rotor blades and subsequent emergency landing. The incident would probably have been avoided if the safety margin between the helicopter and the obstacle had been greater. The safe job analysis did not reveal that the "longline" was too short to provide the necessary safety distance.

The Accident Investigation Board Norway recommends that the Civil Aviation Authority, as head of the Aviation Safety Forum for operators of inland helicopters, ensure that the forum continues the effort to improve the operators' methods for risk assessment of operations in general, and the associated safe job analysis for each job in particular. This can increase the likelihood that all aspects of the relevant hazards are identified, including distance to obstacles, and that the outcome is effective.

Safety recommendation SL no 2019/03T

On Wednesday 14 November 2018, the main rotor of LN-OAN struck the spire on a mast in connection with a nearby mast being dismantled and transported away. This resulted in damage to the rotor blades and subsequent emergency landing. The incident would probably have been avoided if the safety margin between the helicopter and the obstacle had been greater. The safe job analysis did not reveal that the "longline" was too short to provide the necessary safety distance. In particular, it is important that the safe job analysis reflect different challenges associated with the relevant mission, and thus used as a safety net and active barrier to adverse events.

The Accident Investigation Board Norway recommends that the Civil Aviation Authority, in its supervisory work, evaluate the safe job analysis to verify that these are adequate for the relevant missions.

Location
Svanvik, Finnmark, Norway
Occurrence date
14.11.2018
Aircraft
Airbus Helicopter AS 350 B3 Ecureuil
Registration
LN-OAN
Meteorological conditions
VMC
County
Finnmark
Type of occurrence
Serious incident
Type of operation
Commercial, other
Category of operation
Light, helicopter (<= 2 250kg)
Aircraft category
Helicopter, Single-engine, Turboprop/turboshaft
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