On May 16, 1995, a Ryan NAVION (registration N41151) was involved in an aviation accident near Flagstaff, AZ. Investigators recorded the probable cause as: A pitch change control rod end nut backed off and contacted the engine case, causing the control rod to fail and allowing the propeller blade to rotate to the feather position. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
Shortly after lift-off, a propeller blade rotated toward feather, forcing the pilot to land on an embankment. Examination revealed a backed-off pitch change control rod end nut caused the rod to fail.
Accident Narrative
Shortly after lift-off, the airplane experienced a propeller blade that rotated toward the feather position. The pilot was unable to maintain altitude and subsequently landed the airplane adjacent to the runway on an embankment. The airplane then rolled down the embankment.
Examination Findings
Examination of the propeller assembly revealed that a pitch change control rod end nut had backed off and contacted the engine case. This contact caused the pitch change control rod to fail, which then allowed the propeller blade to rotate toward the feather position.
Pilot Background
The pilot, who was a certificated mechanic, had installed the propeller approximately four days before the accident.
Probable cause
A pitch change control rod end nut backed off and contacted the engine case, causing the control rod to fail and allowing the propeller blade to rotate to the feather position.