What happened
On April 2, 2012, at 16:30 UTC, an Aero Boero AB-115, registration PP-GFC, was conducting a visual navigation training flight. The aircraft, operated by Aeroclube de Campinas, departed from Amarais Aerodrome in Campinas, SP, with an instructor and a student on board. The flight plan included a destination of Pouso Alegre, MG, with a touch-and-go maneuver scheduled for Ouro Fino, MG.
Approximately one hour after departure, while attempting to land on runway 06 at Ouro Fino, the aircraft experienced a heavy touchdown. The impact caused the aircraft to tilt sharply to the left, resulting in the left wingtip and propeller striking the ground as the aircraft veered off the left side of the runway. Both occupants escaped the incident without injury, but the aircraft sustained substantial damage.
The investigation
CENIPA investigators examined the structural failure of the left landing gear. Technical analysis conducted by the DCTA (Department of Aerospace Science and Technology) focused on the fractured threaded pin of the shock absorber support. The investigation established that the fracture occurred at the weld region due to an overload.
Detailed inspection of the component revealed poor welding quality performed during aircraft maintenance. The weld was concentrated on the surface, with insufficient penetration into the internal structure of the part. This lack of fusion and inadequate weld depth significantly compromised the mechanical strength of the component. Similar poor-quality welding, characterized by lack of fusion, was also observed on the non-fractured side of the same part.
Findings
- Improper aircraft maintenance involving substandard welding techniques on the landing gear support pin.
- The structural failure of the landing gear pin due to overload, triggered by the heavy landing impact.