What happened
On November 25, 2010, a Eurocopter SA-316B Alouette III, registration OB-1852-P, operated by HELINKA SAC, was performing a flight from Iquitos to a remote helipad at the Kanatari camp in the Maynas Province of Loreto, Peru. The flight was contracted by the mining company "Gran Tierra."
Upon arrival, a passenger requested a low-level flight over the camp area and an approach to a site intended for a new helipad. While the pilot canceled the approach to the new site for safety reasons, the aircraft proceeded to the designated Kanatari helipad. During the final approach, the pilot landed at a 90-degree angle to the helipad's "H" marking. As the pilot lowered the collective to settle the aircraft, the helicopter moved forward and experienced an abrupt 90-degree right turn. The nose wheel drifted off the landing pad and sank into the mud, causing the aircraft to tilt forward. This movement caused the main rotor blades to strike the tail boom, severing the tail rotor and inducing severe vibrations. The pilot subsequently shut down the engine and ordered an evacuation.
The investigation
The CIAA investigation examined the pilot's recent experience, maintenance records, and the operational environment. The investigation found that the pilot had only flown the SA-316B for approximately 0.5 hours in the preceding four years, having not completed required recent proficiency or route checks. Furthermore, the investigation noted that the pilot's English proficiency level was limited, which hindered his ability to fully utilize the company's English-language flight manual.
Technical inspections revealed that the nose gear part number did not match the aircraft's Illustrated Parts Catalog and that the primary braking system was not functioning according to the manufacturer's maintenance manual. Additionally, the investigation found that the Kanatari helipad did not meet the minimum dimension requirements established by ICAO Annex 14.
Findings
- Lack of pilot continuity in operating the SA-316B led to a loss of directional control during landing.
- The pilot's decision to assume command without completing required recent flight training or route checks.
- The nose wheel exiting the landing pad and sinking into mud, leading to an over-control of the cyclic and subsequent rotor-to-tail-boom impact.
- Inadequate helipad dimensions at the Kanatari site.
- Discrepancies in aircraft maintenance, specifically regarding the nose gear part number and braking system performance.
- Operational gaps regarding the training differences between the SA-315 and SA-316B models.