What happened
On September 16, 2014, an Aeromot AMT-600, registration PR-JFS, was performing a local training flight at Brigadeiro Protásio de Oliveira Airport in Belém, Brazil. The flight, involving an instructor and a student pilot, consisted of four circuits, including touch-and-go maneuvers.
During the final landing, after the aircraft had traveled approximately 300 meters along the runway, the pilot experienced vibrations originating from the left main landing gear, followed by a strong tendency for the aircraft to veer to the left. The pilot immediately cut the engine and attempted to maintain directional control using the brakes. During this maneuver, the terminal of the shock absorber failed, leading to the deflation of the left tire. The aircraft subsequently veered off the runway and came to a stop. Both occupants were uninjured.
The investigation
The CENIPA investigation focused on the mechanical failure of the landing gear and the maintenance history of the aircraft. Investigators found that while the aircraft had undergone a scheduled annual maintenance inspection (IAM) in August 2014, the maintenance services were not considered adequate. Specifically, although 50-hour and 100-hour inspections had been performed by a certified mechanic, the required inspection records (as specified in the manufacturer's maintenance manual) were not presented for review.
Crucially, the investigation identified that the aircraft had a history of a similar incident on January 26, 2010, involving the failure of the same type of component. In that previous occurrence, laboratory analysis by IAE-DCTA determined that the failure was caused by fatigue resulting from intergranular corrosion. Although the failed terminal in the 2014 incident was not sent for new laboratory analysis, investigators observed similar conditions on the damaged part to those identified in the 2010 failure.
Findings
- The failure occurred at the labeled terminal (P/N SMG-10) of the left main landing gear shock absorber.
- Inadequate maintenance and lack of proper management supervision regarding maintenance documentation.
- The aircraft had previously experienced an identical landing gear failure in 2010.
- The failure mechanism in the 2010 incident was identified as fatigue due to intergranular corrosion, and similar conditions were visible on the 2014 component.