What happened
On April 7, 2013, an MI-8P helicopter, registration OB-1916-P, operated by Helicópteros del Pacífico S.A.C., was performing a scheduled transport flight of passengers and cargo between Iquitos and the Perenco logistics base at Rio Curaray, Amazonas. The aircraft was carrying a crew of three and 10 passengers.
During the descent phase toward the Rio Curaray helipad, the aircraft experienced a sudden destabilization of flight parameters. The helicopter underwent a mid-ach breakup in flight, with the main rotor blades impacting the tail boom. The aircraft subsequently impacted the terrain in an inverted position and caught fire. All 13 fatalities were located in the forward section of the wreckage.
The investigation
The CIAA investigation examined the wreckage, flight data recorder (FDR) information, and maintenance records. Investigators determined that the aircraft's disintegration occurred while in flight, as evidenced by the wide distribution of debris across an area of 80 by 365 meters.
Analysis of the wreckage revealed that a cargo stowage net had been placed inside the tail boom compartment. During flight, this netting became entangled in the tail rotor power transmission shaft. The friction and tension caused by the net eventually severed the steel cables of the directional control system. Furthermore, the investigation identified discrepancies in the technical documentation of several components, noting the presence of falsified technical records regarding the condition of certain parts.
Findings
- The primary cause of the accident was the sudden loss of directional control and mid-air disintegration caused by the cargo stowage net interfering with the tail rotor control cables.
- The impact of the main rotor blades against the tail boom further compromised the aircraft's structural integrity.
- The crew applied excessive control inputs that exceeded the aircraft's limitations during the emergency.
- Pre-flight inspections were insufficient, as the presence of foreign objects in the tail boom compartment was not detected.
- The crew lacked specific simulator training for directional control failure (pedal failure) emergencies.
- There were significant failures in the operator's quality control and traceability processes, including the use of components with falsified technical documentation.