On March 6, 1990, an Air Tractor AT-301 (registration N23509) operated by Nicks Flying Service, Inc. was involved in an aviation accident near Rolling Fork, MS. Investigators recorded the probable cause as: THE IN-FLIGHT SEPARATION OF THE LEFT AILERON DUE TO IMPROPER MAINTENANCE PROCEDURES AND AN INADEQUATE AIRCRAFT PREFLIGHT. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
While on short final, the pilot could not control the aircraft about the longitudinal axis. The bank continued until impact, and the aircraft came to rest inverted. Investigation found the left aileron separated upward in flight, with three bolts and self-locking nuts missing.
Accident Overview
During the final approach, the pilot was unable to control the aircraft about its longitudinal axis. The banking motion continued until the aircraft struck the ground and came to rest inverted.
Examination Findings
Post-accident examination revealed that the left aileron had separated upward in flight. The three bolts and self-locking nuts used to secure the aileron were not located. There was no damage to the aileron attach arms under the wing or to the aileron's attach points. The aileron push-pull rod was examined and found to have failed due to overload.
Maintenance History
An annual inspection had been performed five days prior to the accident, but the aileron was not removed during that inspection. The aircraft logbook did not contain an entry indicating that the aileron had been removed.