What happened
On the morning of November 20, 2012, an Aérospatiale (Eurocopter) AS350 BA, registration I-MIAE, was engaged in an aerial work mission involving the distribution of vaccine baits. After performing a ground reconnaissance by car to assess local conditions, the crew decided to proceed with the flight despite persistent fog in the area.
Shortly after takeoff from a landing site near a local Bed & Breakfast, the aircraft encountered extremely low visibility. Within seconds of departure, the helicopter entered Instrument Meteorological Conditions (IMC). This sudden loss of visual references likely induced spatial disorientation in the pilot. The aircraft entered a steep descent, striking a chimney on a residential building and severing a medium-voltage power line. The helicopter then impacted a field approximately 640 meters from the takeoff point. The crash resulted in the destruction of the aircraft and the death of both occupants.
The investigation
The ANSV investigation examined the wreckage, meteorological reports, and footage from a camera mounted externally on the aircraft. The wreckage analysis showed significant damage to the main rotor head and transmission shaft, with the tail boom separating due to the force of the impact with a roof.
Meteorological data from nearby stations indicated that while some areas had visibility above 10 km, the specific area of the accident was experiencing heavy fog with tops between 450 and 550 meters. The onboard camera footage confirmed the sequence of events: the aircraft transitioned from VFR to IMC, followed by a noticeable change in pitch and an increase in engine noise, ending with the impact with buildings and the ground. The investigation also noted that the crew had identified an alternative landing field in case the fog worsened, but the accident occurred before they could utilize it.
Findings
- The primary cause of the accident was the pilot's loss of control following spatial disorientation triggered by an unplanned entry into IMC.
- The crew made an inadequate risk assessment regarding the prevailing meteorological conditions.
- The flight was conducted in violation of established VFR regulations and the operator's standard operating procedures, which prohibited starting a flight if weather forecasts suggested VFR compliance could not be maintained.
- Operational pressure, whether real or perceived, to avoid delaying the planned vaccination mission likely influenced the decision to depart.
- Environmental factors, specifically the low visibility caused by fog, were significant contributors to the event.