On August 29, 1985, a Cessna 310B (registration N543GT) was involved in an aviation accident near Hawthorne, FL. Investigators recorded the probable cause as: The autopilot failure for unknown reasons, which caused the aircraft to nose down during final approach. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
The pilot continued flying with a malfunctioning autopilot that was erratic and smoking. The system failed at 1000 feet, causing the aircraft to nose down and crash.
What happened
During a cross-country flight, the pilot reported that the autopilot system became erratic, hot, and began emitting smoke. Despite these clear warning signs, the pilot elected to continue using the automated system. As the aircraft approached approximately 1000 feet above ground level on final approach, the autopilot failed for unknown reasons. This sudden failure caused the aircraft to pitch down abruptly, leading to a crash. The aircraft was totally consumed by a post-impact fire.
The investigation
The investigation focused on the mechanical state of the autopilot system and the sequence of events leading to the accident. Key findings included the pilot's decision to maintain engagement with a malfunctioning unit that exhibited thermal distress and erratic behavior prior to complete failure.
Findings
Contributing factors to this accident include the autopilot failure during critical flight phases and the pilot's continued reliance on a system showing clear signs of malfunction. The lack of immediate disengagement likely exacerbated the severity of the outcome.
Probable cause
The autopilot failure for unknown reasons, which caused the aircraft to nose down during final approach.