On December 14, 2006, a Cessna 310Q (registration N8FH) was involved in an aviation accident near Montgomery, NY. Investigators recorded the probable cause as: Improper maintenance performed on the airplane by maintenance personnel, and the failure of the mechanic with an inspection authorization (IA) to verify the maintenance work performed, which resulted in a reverse elevator trim system, and subsequent loss of… This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
An airplane experienced pitch oscillations after takeoff following an annual inspection, then turned left and impacted trees. Investigation revealed crossed elevator trim cables and full nose-down trim.
Accident Description
The accident flight was the first flight after an annual inspection was completed. After takeoff, the airplane's pitch oscillated as it climbed to approximately 200 to 500 feet above ground level. The airplane then made a left turn, descended, and impacted trees upright.
Maintenance and Inspection Findings
Review of maintenance records and an interview with a mechanic who worked on the airplane revealed that the elevator trim actuator was removed and replaced as part of the annual inspection. A total of four mechanics worked on the airplane, one of whom held an inspector authorization (IA) and endorsed the aircraft logbooks upon completion of the annual inspection.
Examination Results
Examination of the right horizontal stabilizer showed that the upper elevator trim cable crossed the lower elevator trim cable as they traveled from the elevator trim actuator to the pulley located at the center of the empennage. Review of a Cessna Aircraft Company Illustrated Parts Catalog indicated that there should be no crossing of the elevator trim cables traveling from the elevator trim actuator to the pulley at the center of the empennage. Additionally, the elevator trim tab was found in the full (10-degree) nose-down position.