Accident Overview
On 10 July 2003, at 16:45 local time, a SA315B Lama helicopter, registration HB-ZDG, operated by Heli Rezia AG, sustained heavy damage during an external load flight at Alp Rossiglion, municipality Arvigo, Graubünden. The helicopter was performing a commercial external load operation with two passengers on board. The pilot, a Swiss commercial helicopter pilot born in 1960, had accumulated 5068 total flight hours, including 4171 hours on type.
Flight Sequence
The flight was arranged to transport a 200 kg "Helibag" containing construction materials and supplies for a gathering. At 16:30, the helicopter landed at Selma to prepare the load. At 16:42, the pilot departed with flight helper A and two passengers (the event organizer and his mother). Flight helper B remained in Selma after attaching the 20-meter long transport cable to the Helibag and the helicopter's cargo swing.
Approximately three minutes later, the helicopter reached Alp Rossiglion. According to a passenger, the pilot deposited the external load on a flat concrete area. The helicopter then hovered backward several meters without releasing the transport cable. After a slight right shift, the pilot intended to land forward on a suitable spot. During this maneuver, the cable became trapped between two stone slabs. As the helicopter moved, the cable tightened, abruptly stopping the helicopter and causing it to tilt right. The main rotor struck the ground, and the helicopter impacted heavily, coming to rest on its skids.
Injuries and Damage
Both crew members (pilot and flight helper A) and both passengers were uninjured. The helicopter sustained heavy damage. No third-party damage occurred.
Findings and Circumstances
- The pilot held a valid commercial pilot license with a type rating for the SA315 and authorization for mountain landings above 1100 m AMSL.
- No evidence of health impairment or alcohol consumption was found; a blood alcohol test was negative.
- The pilot did not wear a crash helmet.
- All occupants were belted (pilot with four-point harness, others with two-point harnesses); belts withstood the impact.
- The helicopter's mass (1781 kg) and center of gravity were within limits.
- The flight manual (AFM) requires the pilot to release the load after touchdown and ensure release via indicator light or ground personnel signals.
- The pilot stated he decided not to release the cable to save time and intended to land beside the load, focusing on not placing the skids on the cable but neglecting to monitor cable movement. Flight helper A, who had no formal training, was assigned to check the tail rotor clearance.
- Flight helper B, who remained at Selma, had attended a week-long flight helper course in 1997 but had not been offered refresher training since.
- The helicopter was airworthy before the accident; last maintenance inspections were current.
Weather Conditions
The general weather was characterized by flat pressure distribution over Europe with dry air from the northwest. At the accident site, clouds were 1-2/8 with bases around 7500 ft AMSL and isolated cirrus above. Visibility exceeded 30 km. Wind was from the north-northeast at 5-8 kt, gusting up to 15 kt. Temperature was 17 °C, dew point 2 °C. QNH at LSZH was 1018 hPa, at LSZA 1014 hPa. No hazards were identified. Sun azimuth was 256°, elevation 44°.