What happened
On August 10, 2018, an AS 350 B2 helicopter, registration PP-MES, was performing a landing at the INCAPER Farm in Domingos Martins, Espírito Santo. The aircraft, operated by the Secretariat of the Military House (GEES), was transporting two pilots and two passengers, including the State Governor, to the site.
As the pilot attempted to complete the landing procedure by executing a left turn while in a hover, the aircraft's tail rotor collided with a movable soccer goalpost positioned in the center of the field. The impact caused the tail rotor to lose its ability to counteract engine torque, leading to an uncontrolled spin to the and a subsequent loss of control. The main rotor struck the ground, causing the helicopter to tip onto its right side. Despite the substantial damage to the airframe, including the rupture of the tail cone and both the main and tail rotors, all four occupants escaped the crash without injury.
The investigation
CENIPA's investigation focused on the visibility of the obstacle and the operational environment. Investigators found that the goalpost was painted gray and was heavily worn and rusted, providing very little visual contrast against the grass of the soccer field. Furthermore, the time of day—late afternoon—meant that natural lighting was reduced due to shadows cast by the surrounding topography.
The investigation also examined the operational procedures of the GEES. It was established that a standard doctrine existed for such missions, requiring a ground team to be present at the landing site to confirm the area was clear of obstacles. On this occasion, the ground team had not arrived in time, and the crew proceeded with the landing without coordination with ground personnel. Additionally, the investigation looked into the pilot's workload, noting that the pilot in command had been managing significant administrative tasks and had performed multiple flights that day without a meal break.
Findings
- Inadequate risk assessment: The decision to proceed with the landing without the support of the established ground team meant the crew failed to verify the landing zone was free of obstacles.
- Reduced situational awareness: The combination of the low-contrast gray paint on the goalpost, the worn condition of the obstacle, and the reduced lighting from topographical shadows made the goalpost difficult to identify.
- Inadequate flight planning: The mission was activated without sufficient time for the necessary administrative and operational preparations at the destination.
- Workload and fatigue: The pilot in command was experiencing a high workload due to the accumulation of administrative and flight duties, which likely compromised operational performance.
- Decision-making pressures: The presence of a high-ranking government official as a passenger may have introduced self-imposed pressure to complete the mission quickly, potentially affecting the quality of the crew's decision-making.