What happened
During the landing phase, the aircraft experienced a catastrophic failure of the right main landing gear assembly. Upon initial contact with the runway surface, the axle supporting the right main wheel fractured completely. This structural failure caused the wheel to detach from the strut assembly. Following the separation of the wheel, the remaining strut stub impacted the ground, causing the airplane to veer sharply to the right.
The investigation
Post-accident examination of the failed components provided critical insights into the mechanism of failure. Forensic analysis of the fracture surfaces on the broken axle revealed distinct metallurgical evidence. A pre-existing crack was identified along the bottom one-third of the axle circumference. This area likely represents a zone of high stress concentration during normal operation. The remainder of the fracture surface appeared fresh, indicating that the final separation occurred suddenly and dynamically at the moment of touchdown.
Findings
The investigation determined that the failure was not initiated by the landing impact itself but rather by a latent defect in the axle. The presence of the pre-existing crack suggests a fatigue process had been progressing prior to the accident event. When the aircraft loaded the gear during touchdown, the remaining cross-section of the axle could no longer support the operational loads, leading to immediate rupture. This failure mode highlights the critical importance of inspecting landing gear components for early signs of fatigue cracking, particularly in high-stress areas such as the bottom of the axle where bending moments are highest.