Factual Information
On 28 August 1990, at approximately 0715 hours local time, a SA 315B Lama helicopter, registration HB-XRE, operated by Air Glaciers SA, was involved in an accident at Fratsay, Champex (Commune d'Orsières), Switzerland. The helicopter was engaged in commercial timber extraction, a task it had performed for about two weeks in the region since April. The pilot, a Swiss national born in 1952, held a valid professional helicopter pilot license issued on 19 November 1976, with total flight experience of 7033 hours, including 5000 hours on type. The helicopter was properly maintained and in airworthy condition; its mass and balance were within prescribed limits.
Accident Sequence
At 0700 hours, the pilot departed from Sion aerodrome with two flight assistants on board. He dropped them off at a clearing on a slope, the same location where two loggers were to be deposited later. The pilot then flew to Champex, where a third flight assistant and a team of loggers were waiting. After boarding two loggers, the pilot returned to the landing site.
The approach was made perpendicular to the slope, which had a 30° incline. Wind was calm and visibility perfect. The pilot positioned the helicopter sideways and set the left skid on the stony ground. A flight assistant opened the left door and helped the first logger exit, instructing him to crouch to the right. The assistant then opened the door again, which had closed, and assisted the second logger out. During this process, the first logger stood up and moved uphill from the hovering helicopter, striking his head against the main rotor approximately 20 cm from the blade tip. The impact was fatal. The second logger was still on the skid at the time. No evasive action was possible.
Findings
The pilot was licensed and medically fit. The helicopter was in normal operational condition. All approach, landing, and disembarkation maneuvers were performed correctly. Safety measures were in place: a flight assistant in radio contact with the pilot received the helicopter and assisted passengers with due caution. The passengers had received instructions on helicopter safety, including a reminder on the day of the accident. The landing site was a stony slope with a rotor tip clearance of one meter at the lowest point. No alcohol or medications were found in the deceased logger. The accident was not influenced by any operational deficiencies.
Cause
The accident was caused by the inadequate and unpredictable behavior of a passenger during disembarkation on uneven terrain.