What happened
On September 18, 1998, a Bell 206B Jet Ranger, registration PT-HTL, was engaged in a specialized mission to transport technicians for the inspection of electrical transmission towers near Nova Cantu, Paraná. The mission involved checking towers for the presence of explosives.
During the operation, the pilot attempted to land the aircraft near a tower. While the helicopter was in a hover, a technician attempted to board the aircraft by stepping on the skid. This action, combined with strong crosswinds, caused the aircraft to oscillate. As the technician moved toward the cabin, the pilot lost control of the aircraft. The main rotor blade struck the ground, causing the helicopter to roll to the right. The impact resulted in one fatality (the technician attempting to board) and one injury (a passenger on board), while the pilot remained uninjured. The aircraft sustained severe damage to the structure, engine, main rotor, and transmission.
The investigation
CENIPA's investigation focused on the environmental conditions, the pilot's operational state, and the organizational oversight of the operator, Atlântico Sul Aerotáxi. Investigators found that the aircraft was operating in a crosswind of approximately 15 knots with gusts up to 25 knots, which exceeded the 17-knot operational limit for crosswind landings in this aircraft type.
The investigation also examined the pilot's workload, noting he had flown 78 hours in 13 days, approaching the legal monthly limit of 90 hours. Furthermore, the investigation identified organizational failures, including the lack of a formal training program for the specialized mission and irregularities in the company's operational authorization, as the aircraft was operating in a specialized category (SAE) while only authorized for air taxi (TPX) operations.
Findings
- Improper maneuvering: The pilot used flight controls inadequately during the hover, which, when combined with the wind, led to the loss of control.
- Environmental factors: The aircraft was operated in crosswind conditions exceeding its established operational envelope.
- Human factors: The pilot was experiencing high levels of stress due to a heavy workload and the high-risk nature of the mission.
- Inadequate passenger coordination: The technician attempted to board the aircraft in a manner that contradicted the pilot's briefing and caused instability.
- Organizational deficiencies: The operator lacked a proper training program and failed to provide adequate supervision or a co-pilot for such a high-risk mission.