Factual Information
On 16 July 2010, at approximately 14:10 local time, a Eurocopter AS350 B3 helicopter, registration HB-ZJO, operated by Heli-TV SA, was conducting an external load operation from the roof of the Madonna del Sasso church in Orselina, in the canton of Ticino, Switzerland. The helicopter had a takeoff mass of 2429 kg, including a 900 kg external load consisting of a pallet of 40 bundles of Campa tiles still in original plastic wrapping.
Narrative
The operation was part of a work plan involving two helicopters and three flight helpers. For the second task, a flight helper positioned himself on the church roof with a carpenter and a painter. The flight helper prepared the pallet single-handedly using four strapping bands. He asked the carpenter and painter to hold the straps until tensioned by the helicopter. The pilot lowered a 50-meter longline, and the flight helper attached the straps to the hook. He then instructed the pilot to lift slowly. As the pallet lifted approximately 50-70 cm on one side, it began to tilt, causing the tile bundles to slide. The pilot noticed the issue and radioed the flight helper to detach the straps so he could land. However, the carpenter was struck by the sliding tiles, slid four meters down the roof, and fell headfirst 3.10 meters to the ground. He was able to stand up but was transported to a hospital for four days of neurological monitoring. The helicopter sustained no damage; minor damage occurred to a part of the church roof.
Meteorological Conditions
At the accident site, weather was partly cloudy with 2-3 oktas at 7000 ft, visibility 8 km, southwest wind 2-5 kt, temperature 30°C, dew point 18°C, QNH 1017 hPa at LSZH. High temperatures were noted as a hazard.
Organizational and Training Aspects
The operator, Heli-TV SA, employed four permanent pilots and eleven full-time flight helpers. The company's Flight Operations Manual (FOM) was approved in 1991, with a revised version from 2006 not yet approved. The organizational chart was noted as not meeting organizational requirements. At the time, no recognized apprenticeship existed for flight helpers; training was based on a syllabus and safety brochures from the Swiss National Accident Insurance Fund (SUVA).
Probable Cause
The accident was caused by the fact that during the lifting of a pallet, its load fell and injured a worker. The technique of attaching the pallet to the sling was not appropriate.