What happened
On July 6, 2021, at 16:30 UTC, a Cessna 560, registration LV-AHX, was taxiing toward the active runway at San Fernando International Airport in Buenos Aires, Argentina. The aircraft was scheduled for a ferry flight to Salta. While approaching the holding point for runway 05, the crew noticed the aircraft began to decelerate unexpectedly and observed the nose of the plane dipping toward the ground. The crew immediately requested assistance from air traffic control and evacuated the aircraft, discovering a failure in the nose landing gear assembly. The incident resulted in minor damage to the nose gear fork and the gear cover.
The investigation
The investigation focused on the structural integrity of the nose gear fork (part number 6642000-3), the wheel axle, and the bushings. Laboratory analysis conducted by the Fábrica Argentina de Aviones (FAdeA) revealed significant evidence of high-temperature friction and plastic deformation. Specifically, the left end of the fork showed a fracture accompanied by signs of heat exposure, including blistering and peeling of the surface paint. On the right side of the fork, investigators found circumferential wear and material displacement within the bushing housing.
Further examination of the wheel axle revealed dark, circumferential grooves and material buildup, suggesting that the bearings and the fractured end of the fork had been rubbing against the axle. While the manufacturer, Textron Aviation, noted that similar cracks have occurred in this model—often attributed to seized bearings due to insufficient lubrication—the laboratory tests found no evidence of fatigue, corrosion, or pre-existing cracks in the metal. The aircraft's maintenance records showed the component was within its service life, with 415 cycles remaining before a scheduled replacement.
Findings
- The nose landing gear fork failed while the aircraft was taxiing near the runway holding point.
- Laboratory testing showed no evidence of fatigue, porosity, or corrosion that could have initiated the failure.
- The specific origin of the structural failure could not be determined due to the lack of identifiable crack initiators or evidence of lubrication failure.