Accident Sequence
The aircraft had reached its cruise altitude of 8,500 feet when the engine smoothly quit. The pilot contacted a nearby airport control tower, reported the power failure, and stated the need to land. The local controller cleared the flight to land on any runway. Shortly thereafter, the pilot radioed that he would not make the field and subsequently performed a gear-up landing in a dry wash area. During the landing, the aircraft collided with trees and an embankment.
Examination Findings
Examination of the airplane disclosed that the mixture control cable was fractured and disconnected from the cable's rod-eye end, which remained attached to the mixture arm of the fuel metering unit. The break occurred at the engine rod-eye end of the flexible cable, at the point where the cable is swaged onto the rod. A metal outer sheath slides over the rod, and the eye end of the rod is longitudinally adjustable so that the rod and cable can ride inside the outer metal sheath to provide support against bending loads. The length adjustment nuts on the rod-eye end were found adjusted all the way down, positioning the cable-to-rod swage point outside the sheath at the full rich mixture setting.
Metallurgical examination of the cable determined that it failed in fatigue due to excessive and repetitive bending. According to the maintenance records, the mixture control cable had been replaced at the last annual inspection on June 2, 1998, 99 hours prior to the accident. No other anomalies were found with the engine or its related systems.