What happened
On March 5, 2017, an AW13MS helicopter, registration I-TNCC, was engaged in a Helicopter Emergency Medical Service (HEMS) mission near Cima Nambino, Madonna di Campiglio. The crew had been tasked with rescuing two skiers who had been struck by an avalanche, one of whom was buried in the snow.
Upon arrival at the site, the pilot attempted to land, but the maneuver was aborted due to a white-out effect caused by snow being kicked up by the main rotor downwash. The crew decided to reposition the aircraft to perform a winch operation to lower a rescue technician and a canine unit to the ground. During this maneuver, a sudden further reduction in visibility occurred, leading the aircraft to impact the ground at a low altitude.
While the pilot ordered the release of the personnel being winched, the rescue technician and the dog handler were partially submerged in the snow and could not immediately detach. The pilot did not initiate the winch cable cut command. The impact resulted in 7 people on board sustaining injuries, including 1 serious injury and 6 minor injuries.
The investigation
The ANSV investigation examined the flight data, cockpit voice recordings, and meteorological conditions at the time of the accident. The inquiry focused on the crew's decision-making process, the effectiveness of Crew Resource Management (CRM), and the impact of environmental factors on flight stability. Investigators also reviewed the aircraft's technical state and the operational procedures for HEMS missions in mountainous terrain.
Findings
- The pilot experienced spatial disorientation following the loss of visual references caused by the white-out condition, leading him to believe the helicopter was stationary when it was actually moving forward.
- There was a lack of effective Crew Resource Management (CRM) between the pilot and the cabin crew, which prevented the sharing of critical information during the winch operation.
- The pilot elected to perform the winch maneuver in highly variable meteorological conditions and at an altitude lower than those prescribed by the operator's manual.
- The crew was aware of critical weather conditions reported by other aircraft and local mountain rescue services prior to the mission.
Safety action
- The ANSV recommended that EASA develop guidance for daytime HEMS operations in specific geographical areas where complex topography and sudden visibility changes may necessitate the use of two pilots to assist with instrument monitoring.
- The ANSV recommended that ENAC encourage HEMS operators to provide combined CRM training to all crew members, including medical personnel, to improve information sharing during critical flight phases.