Incident Overview
During a missed approach, the aircraft experienced a partial power loss while transitioning to a climb. The pilot executed a course reversal to return visually to the airport. Shortly thereafter, the pilot chose to perform an emergency landing on a frontage road that ran parallel to railroad tracks. During the approach, the aircraft struck communication lines and subsequently a pole.
Examination Findings
Post-incident examination of the throttle cable revealed that it had slipped free of its attachment point at the carburetor. The throttle cable had been replaced on December 7, 1982. The aircraft had been operated for 2.7 hours since the installation, which corresponded to the flight time from Portland, Oregon, to Pocatello, Idaho.
Probable Cause
The probable cause of the incident was the throttle cable slipping free of its attachment point at the carburetor.