What happened
On January 18, 2000, an AS-3PT BA helicopter, registration PP-EOG, was conducting a police aerial search and containment mission near Mairiporã, São Paulo. The crew, consisting of four military personnel from the São Paulo Military Police Air Patrol Group, was searching for suspects involved in a carjacking.
While patrolling the Fernão Dias Highway at a low altitude, the pilot identified a suspicious vehicle and coordinated with ground units. After performing a brief hover to support ground officers, the pilot initiated a spiral climb to approximately 70 feet (210 ft) to avoid known high-voltage lines in the area, before leveling off to resume the low-altitude patrol. During this phase, the aircraft struck two high-voltage power lines that crossed the highway perpendicularly. Although the pilot attempted an evasive maneuver, the collision was unavoidable. The pilot managed to execute an emergency landing in a nearby vegetated area. The impact resulted in four minor injuries among the crew and the total destruction of the aircraft.
The investigation
CENIPA's investigation focused on the operational environment and the circumstances leading to the collision. Investigators found that the high-voltage wires were not marked with required aviation warning lights, making them difficult to detect from the pilot's perspective.
The investigation also revealed a significant lack of standardized procedures within the Air Patrol Group. At the time of the accident, the unit lacked a formal manual of doctrine or specific protocols for conducting aerial police operations. Furthermore, the pilot was found to be unaware of the minimum safety altitude requirements established by Brazilian air traffic regulations, as the unit's prevailing culture encouraged maintaining low altitudes for better visual surveillance of suspects.
Findings
- Organizational Culture: A culture of non-compliance with safety limits existed, where maintaining low altitudes in the presence of obstacles was a common practice.
- Lack of Doctrine: The absence of standardized operational manuals for police aviation led to improper decision-making regarding flight altitude.
- Inadequate Obstacle Marking: The high-voltage power lines lacked the required signaling/beacons, hindering the pilot's ability to identify the hazard.
- Improper Judgment: The pilot failed to maintain a safe altitude despite being aware of the presence of power lines in the region.
- Deficient Supervision: The command of the Air Patrol Group permitted operations without established safety doctrines or standardized procedures.