Primary finding
Probable cause
Fractured nose landing gear bolt due to fatigue.
Investigator assessment
Analysis narrative
The pilot noted an unsafe indication after lowering the landing gear and observed through a mirror the nosewheel was not locked. He elected to land wheels up. Post incident inspection disclosed the bolt that attaches the upper drag link to the nose gear trunnion had sheared. Laboratory examination disclosed torsional bending fatigue typical of high cycle low load fatigue.
Source record
Factual narrative
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