Primary finding
Probable cause
The separation of a nose landing gear axle retaining nut and the subsequent the failure of the nose landing gear during landing.
Investigator assessment
Analysis narrative
The student pilot and flight instructor described that during the landing roll the student pilot smelled a “burnt” smell, and that as the airplane continued to slow, drifted to the left. The student applied right rudder, but the airplane did not respond. He then applied the brakes and the nose landing gear immediately collapsed. The lower forward portion of the airplane’s fuselage was substantially damaged during the accident sequence. A Federal Aviation Administration inspector examined the airplane after the accident and provided photos of his findings that were examined in detail. The examinations revealed that the nose landing gear fork was separated from the upper portion of the nose landing gear assembly. Additionally, one of the nuts securing the nose landing gear’s axle was missing, while the threads on the axle were intact. The opposite end of the axle retained its nut, which was still secured with a cotter pin. The nose landing gear fork fracture surfaces exhibited fracture features consistent with overstress, and signatures consistent with the nosewheel rubbing against it before the fracture occurred. Based on this information, it is likely that one of the nuts securing the nosewheel axle was not properly secured and separated from the axle. This allowed the axle to displace laterally, resulting in the nosewheel making contact with the fork, and its subsequent failure.