Flight History
On 26 September 2013, the pilot of a Eurocopter EC120B, registration HB-ZIX, operated by Alpinlift Helikopter AG, planned a flight from Buochs to Trogen. The pilot intended to land at Seemattli near Seewen to pick up two passengers. However, at the passengers' request, the landing site was changed to their farm at Oberes Herrenfeld, Gemeinde Schwyz. The pilot had reconnoitred the area around the farm a year earlier and considered it unsuitable for landing due to the sloping terrain with few flat areas.
The helicopter departed Buochs at 15:38 local time. The pilot landed at the farm at 15:47, setting the left skid on a paved area in front of the house and the right skid on a gravel area adjacent to a barn. The takeoff was delayed due to a technical issue with a warning light (ENG CHIP). After consulting a mechanic, the pilot proceeded with the flight. The helicopter departed at 15:58, heading to Trogen.
After picking up the pilot's son in Trogen, the pilot returned to the farm at 17:25, landing on the same spot. The two passengers (the couple) disembarked and moved to a safe location. The pilot then increased power to initiate a controlled hover and forward flight.
Accident Sequence
During takeoff from the hover, the pilot began a forward translation. The main rotor blades struck the eave of the barn, which projected 3.3 meters beyond its outermost support pillar. The pilot later stated that he was unaware of the overhanging roof and was surprised by the loud impact. The helicopter then fell from a height of about 2 to 3 meters, impacting the ground, rolling onto its left side, and sliding toward the two passengers. A metal fragment struck the female passenger's legs, causing serious injury. The pilot and his son exited the helicopter uninjured.
Aircraft and Personnel
The helicopter was a Eurocopter EC 120B "Colibri", registration HB-ZIX. The pilot held a Swiss commercial pilot license (CPL(H)) with type rating for the EC120B and mountain landings. He had 411 total helicopter flight hours, 192 on type. The aircraft was destroyed. The barn eave was severely damaged.
Cause
The accident was due to the collision of the main rotor with the eave of a barn during takeoff from an inadequate landing site. Subsequently, the helicopter struck the ground uncontrollably.