Accident Description
The airplane was descending for landing, approximately 3 miles from the destination airport. The pilot adjusted the throttle to level the aircraft, but the engine continued running at the descent power setting. Further throttle adjustments caused no change in engine speed. Based on the wind and available power, the pilot initiated a forced landing to a parking lot. During the landing flare, while maneuvering to avoid obstacles, the left wing contacted the ground. The airplane then landed hard, causing the nose gear to collapse, and subsequently struck a curb before coming to rest.
Investigation Findings
Examination by Federal Aviation Administration (FAA) inspectors revealed a severed throttle cable. The cable was sent to a National Transportation Safety Board metallurgist for analysis, which determined that the failure was due to fatigue. The wear around the cable housing was described as "uniform" and "severe," consistent with exposure to contaminants, vibration, and bending loads. The cable had been installed 4 years and 1,200 flight hours prior to the accident.
Probable Cause
The throttle cable failed in fatigue due to uniform severe wear from contaminants, vibration, and bending loads.