What happened
On February 3, 2000, a Bell 206 helicopter, registration PT-HON, operated by Táxi Aéreo Kovaks S.A., was conducting a low-altitude inspection of electrical transmission lines between Tucuruí and Cametá, Brazil. The flight, which included the pilot and three passengers, encountered deteriorating weather conditions characterized by heavy rain and strong winds near a Cumulus-Nimbus formation.
As visibility became severely restricted, the pilot decided to abort the mission and seek an alternative landing site. After performing a 18/0º turn, the pilot identified a clearing near the transmission lines. During a steep approach to this site, the aircraft's vertical stabilizer became entangled with a steel lightning protection cable. In an attempt to free the aircraft, the pilot applied maximum power and aggressive forward cyclic input. This caused the cable to snap, but the resulting aggressive nose-down attitude and high power setting prevented the pilot from recovering control, leading to a fatal impact with the ground.
The investigation
CENIPA's investigation focused on the sequence of events leading to the entanglement and the subsequent loss of control. Investigators examined the pilot's decision-making process, the meteorological conditions, and the operational procedures of the operator. The investigation established that the pilot, despite being highly experienced, failed to seek flight authorization from air traffic control (SRPV-Belém) and did not consult updated meteorological reports before departure. Furthermore, the investigation noted that the pilot's high level of self-confidence may have influenced his decision to continue the flight despite the worsening weather and to attempt a landing in a high-risk area near power lines.
Findings
- Adverse weather conditions: Heavy rain significantly reduced visibility, making the dark lightning protection cable nearly impossible to detect against the terrain, while strong gusts destabilized the aircraft during approach.
- Improper decision-making: The pilot demonstrated excessive self-confidence, which delayed the decision to terminate the flight and led to the choice of a risky landing site near high-voltage infrastructure.
- Operational deficiencies: The operator failed to implement adequate supervision, as the flight was conducted without proper authorization or communication with air traffic control.
- Lack of passenger briefing: The pilot failed to brief passengers on emergency procedures; notably, one passenger unbuckled their seatbelt in an attempt to evacuate immediately, which resulted in them being thrown from the aircraft during the impact, causing serious injuries.
- Loss of control: The aggressive maneuver to break the cable caused an unrecoverable pitch-down attitude at low altitude.