Incident Summary
A pilot reported that engine problems developed during a cross-country flight, prompting a precautionary landing at a private airstrip. The pilot stated that the touchdown was normal, but approximately 4-5 seconds after the landing rollout began, a loud popping sound was heard from under the seat. Shortly thereafter, the right main landing gear collapsed.
Landing Details
According to the pilot, the landing gear collapse occurred after the audible pop. The sequence of events was described as a normal landing followed by an unexpected structural failure in the landing gear system.
Post-Accident Examination
A post-accident examination of the airplane's landing gear was conducted by representatives from the Federal Aviation Administration (FAA) and the operator. The examination revealed that the center gear attach bolt and its corresponding locking nut for the right main landing gear leg were missing. The bolt was later recovered, but the locking nut was not found. The recovered bolt was intact and showed nominal wear. There was no evidence of thread failure or significant mechanical damage on the bolt.
The operator reported that the absence of the nut and bolt allowed the landing gear leg to separate from its corresponding attach assembly. The investigation did not determine why the missing nut separated from the bolt and landing gear assembly.