What happened
On August 5, 2000, at approximately 20:30 local time, an Aerospatiale Alouette II SE 3130, registration F-GJIE, was performing aerial application services over a rice field at Finca "Casanova" in the municipality of Pals, Gerona. The aircraft was engaged in agricultural spraying operations when a change in wind direction forced the pilot to alter the flight path of the treatment passes. This adjustment left the edge of the field, which bordered a wooded area, for the final pass.
During this final pass, the pilot flew a trajectory nearly parallel to the field boundary and in close proximity to trees. In an attempt to gain altitude, the helicopter struck electrical cables that were running perpendicular to the flight path. The impact caused the pilot to lose control of the aircraft, which drifted to the right and struck an embankment at the edge of the field. The aircraft was destroyed, though the pilot remained uninjured.
The investigation
The investigation focused on the operational requirements of agricultural spraying and the pilot's situational awareness. To ensure the effective application of phytosanitary products, pilots must maintain a very low altitude. This necessity creates a constant tension between maintaining flight safety and ensuring the quality of the treatment.
Investigators examined the pilot's workload during the final pass. The pilot reported that significant attention was required to maintain safe separation from the nearby trees. While the pilot was aware of the existence of the power lines, the investigation established that the pilot lost visual contact with them during the maneuver.
Findings
- The primary cause of the accident was the impact with electrical cables during a period of high pilot workload.
- The necessity of flying at low altitudes to optimize crop treatment increased the risk of ground and obstacle collision.
- The simultaneous requirement to monitor tree proximity and maintain low altitude saturated the pilot's capacity to maintain visual contact with the power lines.
- A change in wind direction contributed to the modified flight path that placed the aircraft in a more hazardous position near the tree line.