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ASN Wikibase Occurrence # 247338
Last updated: 6 March 2021
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Type:Silhouette image of generic AS50 model; specific model in this crash may look slightly different
Eurocopter AS 350B3 Ecureuil
Registration: HB-ZCZ
C/n / msn: 3434
Fatalities:Fatalities: 0 / Occupants:
Other fatalities:0
Aircraft damage: Minor
Category:Serious incident
Location:Barrage de Tseuzier, 5 km nord-ouest de Crans-Montana -   Switzerland
Phase: Approach
Nature:Passenger - Non-Scheduled/charter/Air Taxi
Departure airport:Sion Airport (SIR/LSGS)
Destination airport:Barrage de Tseuzier
Investigating agency: STSB Switzerland
The mission of this flight was to bring three workers to a dam for inspection work that was carried out once a month.
After the takeoff from the airport of Sion (LSGS), the reduced visibility conditions forced the pilot to undertake an approach by the left bank of the dam. Without carrying out a reconnaissance flight before the approach, the pilot intended to fly over the power line he knew, then to carry out the final approach along the wall of the dam. Shortly before reaching the dam, the pilot was surprised by the power line.

As the pilot later stated, he knew the line well, but he estimated his position a little further north and at a lower altitude in the valley.
The pilot noticed that the helicopter touched the power line. The pilot did not notice any vibration or an overshoot of the engine parameters; he continued his approach and landed the helicopter without problem on the planned landing zone. As the meteorological conditions deteriorated the pilot did not carry out a complete stop of the helicopter but only an engine idle.
After a 5 minutes flight back to base, damage on the leading edge of a blade of the main rotor was found. No other parts of the helicopter were affected.



Accident investigation:
Investigating agency: STSB Switzerland
Status: Investigation completed
Download report: Final report



Photo of HB-ZCZ courtesy

Sion (LSGS / LSMS / SIR)
8 February 2018; (c) Michiel van Herten

Revision history:

01-Feb-2021 10:11 harro Added
01-Feb-2021 10:15 harro Updated [Source, Category]
05-Mar-2021 19:57 Aerossurance Updated [Source]
06-Mar-2021 09:47 Aerossurance Updated [Embed code]

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