What happened
On November 5, 2020, a private Fairchild SA-227AC, registration LV-VDJ, was performing a general aviation flight from San Juan to Mendoza. During the landing phase at El Plumerillo Airport, approximately 400 meters after touchdown on runway 18, the right main landing gear collapsed. This failure caused the aircraft to veer from the runway centerline, traveling roughly 740 meters before exiting the right margin of the runway and coming to a stop perpendicular to the pavement.
The aircraft sustained significant damage, including impacts to the right main gear, the right flap, the area behind the landing gear housing, and the right propeller. There were no injuries to the two crew members on board.
The investigation
Investigators examined the fractured components of the right main landing gear, specifically identifying that both drag braces had failed. Laboratory analysis of the fractured parts revealed a ductile fracture pattern and ruled out pre-existing fatigue, corrosion, or erosion as causes. The metallurgical study confirmed that the components were made of a 2000-series aluminum alloy and showed no signs of cracks or defects that could have initiated the failure.
Maintenance records indicated that the aircraft was compliant with Airworthiness Directive AD-2000-17-11, which requires dye penetrant inspections of the drag braces every 1,000 flight hours. The most recent inspection had been completed only 46.9 hours and 33 cycles prior to the accident, with no anomalies detected at that time.
Additionally, investigators were unable to review cockpit audio due to the cockpit voice recorder (CVR) having a jammed magnetic tape, which prevented recording during the event.
Findings
- The right main landing gear collapsed due to the simultaneous fracture of both drag braces.
- Laboratory evidence suggests the fracture mechanism was ductile, indicating that the components were exposed to loads exceeding their design limits.
- The internal drag brace appears to have failed first, subsequently causing the external drag brace to fail under the resulting stress.
- No pre-existing cracks, fatigue, or environmental degradation were found to have contributed to the structural failure.