Amateur-built SPORTSMAN GS-2 N209TP accident near El Dorado Hills, California

Probable cause

The in-flight separation of the elevator control torque tube rod end bearing from the elevator torque tube as a result of incorrectly tightened rod end bearing lock nuts.

NTSB analysis

Witnesses monitoring the accident flight's departure airport common traffic advisory frequency reported that they heard a mayday radio transmission stating that "I've lost elevator control" and "I'm going down in some trees." Witnesses adjacent to the accident site reported hearing a loud whining noise followed by the sound of something impacting trees. One witness stated that the airplane was at a low altitude in an upright attitude when it struck trees. The airplane subsequently impacted terrain and came to rest near a residential structure where a post-crash fire consumed most of the fuselage. Post-accident examination of the wreckage revealed that the elevator torque tube was disconnected from the forward rod end bearing. The forward rod end bearing remained attached to the elevator bell crank assembly. No damage was observed on the forward torque tube rod end threads or forward rod end bearing threads. The forward torque tube rod end jam nut was observed threaded about one-half inch from the threaded rod end. The aft torque tube jam nut and torque tube rod end was observed against the aft rod end bearing. The aft torque tube rod end was slightly bent and did not allow movement. No evidence of "torque seal" was observed on the forward or aft jam nuts, rod end bearings, or torque tube assembly. No additional mechanical anomalies were noted with the recovered airframe.

Text from the NTSB. Open the NTSB docket for WPR09LA202 for the full record.