What happened
On July 18, 2019, at approximately 20:30 UTC, an AS 350 B2 helicopter, registration PR-HFA, operated by the Brazilian Federal Police, was conducting a specialized mission to eradicate marijuana plantations in Orocó, Pernambuco. The aircraft was transporting a crew of three and two passengers (Federal Police officers) to a target location.
To expedite the mission and ensure a return to base before sunset, the crew decided to transport the officers externally using specialized techniques. One officer was attached to the aircraft's skid using the "mata-leão" technique, while the second officer, who was experiencing shoulder pain, requested to be transported using the "preguiça" technique. During the approach for deployment, the officer using the "preguiça" technique lost his grip and fell from a height of approximately six meters. Shortly after, the second officer also detached from the aircraft and fell.
The crew landed near the fallen officers to perform a rescue, and the aircraft proceeded to Salgueiro Aerodrome to ensure the injured passengers received medical attention. The three crew members were uninjured, but the two passengers sustained serious injuries. The aircraft sustained no damage.
The investigation
CENIPA's investigation focused on the mission management and the technical validity of the transport methods used. Investigators found that while the crew was highly experienced and the aircraft was airworthy, the mission planning was flawed. The crew had estimated the transit time to be only 30 seconds, whereas the actual flight time was significantly longer, requiring a higher degree of stability than the officers could maintain.
The investigation also examined the Standard Operating Procedures (SOP/POP) of the CAOP unit. It was noted that the "preguiça" technique was intended only for momentary boarding or disembarking, not for actual transit between locations. Furthermore, the aircraft's flight manual (MAPRO) lacked specific guidance regarding these external transport techniques, and the "mata-leão" technique lacked clearly defined parameters for maximum distance, speed, or duration.
Findings
- The decision-making process was compromised by an attempt to expedite the mission to avoid flying in darkness.
- Improvisation of the "preguiça" technique for transit, rather than just for boarding, weakened operational safety.
- An inaccurate estimation of flight time (30 seconds) led to an inadequate risk assessment.
- A group culture that valued high-risk maneuvers as a sign of excellence contributed to the disregard for established safety boundaries.
- Inadequate flight planning and a lack of specific technical parameters (speed, altitude, and duration) in the organizational support systems.