On August 19, 1988, an Air Tractor AT-301A (registration N73089) was involved in an aviation accident near Shelby, MS. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
During ground roll for an aerial application flight, two main gear bolts failed, causing the gear to trail aft and the aircraft to veer off the runway into a soybean field and nose over. Examination showed no pre-existing failure, but the bolts had exceeded the recommended replacement interval.
Accident Overview
During the ground roll phase of an aerial application flight, the forwardmost of two main gear clamp block bolts on the right main landing gear failed. Subsequently, the landing gear trailed aft. Additionally, the inboard main gear large bolt also failed. The aircraft departed the runway, entered a soybean field, and nosed over.
Examination and Maintenance History
A post-accident examination of the failed bolts revealed no evidence of pre-existing failure. According to the aircraft maintenance manual, both of the failed bolts were required to be replaced at a maximum interval of 600 hours and a minimum interval of 300 hours, depending on general landing field conditions. The operator of the aircraft reported that both bolts had accumulated approximately 670 hours since their last replacement, exceeding the maximum recommended service life.