Flight Sequence
On the morning of 19 July 1990, the pilot of a SA 315B Lama helicopter (HB-XTO) was conducting concrete transport rotations in the Binntal region. During the 17th rotation, the concrete bucket suspended from a 10-meter cable struck a boulder and was damaged. Under time pressure, the pilot flew to a nearby external station to obtain a replacement bucket, then returned to the loading area. He set the empty bucket down in front of a concrete tipper lorry, moved the helicopter back, released the transport cable, and performed a quarter-turn to the left while descending slowly. Before landing, the main rotor contacted the upper part of the concrete container standing vertically on the tipper lorry. The helicopter crashed from low altitude and was destroyed.
Injuries and Damage
The pilot and one flight assistant sustained serious injuries. Another flight assistant sustained fatal injuries and died on 20 August 1990 without regaining consciousness. The helicopter was destroyed. The building of the cable car station and several vehicles were damaged.
Investigation Findings
The collision of the rotor blades with the concrete container on the tipper lorry was due to an inattention of the pilot during the depositing of a concrete bucket followed by a landing in immediate proximity. Contributing factors included the unsuitable location of the loading area in relation to the scope and nature of the transport, and psychological pressure on the pilot.