Piper PA 28R-200 N9336N accident near Bowie, Texas

Probable cause

The inadequate maintenance and inspection of the throttle control arm, which resulted in its in-flight separation and the subsequent loss of engine power.

NTSB analysis

The commercial pilot reported that he had just completed a cross-country flight and had been cleared for the approach when, during the descent, the engine did not respond when he pulled back on the throttle. When the pilot enriched the fuel/air mixture, the manifold pressure decreased, and the engine lost power. The pilot conducted a forced landing to a field, during which the airplane's wing sustained substantial damaged.

The examination of the engine revealed that the throttle control arm, which was original hardware to the airplane, was separated from the joint assembly. Additionally, the female end of the throttle arm exhibited elongation at the linkage attachment point and was consistent with wear developing over time. An examination of the airplane, engine, and remaining systems revealed no other anomalies that would have precluded normal operation.

The airplane manufacturer had issued a nonmandatory service letter (SL) recommending that the throttle arm and joint assembly be replaced with a new refinement kit if any indication of wear existed; a review of the engine logbooks found no record of compliance with the SL. Although the pilot reported that the airplane's last inspection was an annual inspection, he did not provide the date of the inspection, and it was not noted in the logbook. Given the condition of the throttle linkage attachment, it is likely that the inspection of the throttle linkage attachment was either not performed or was inadequate. Investigators were unable to determine what the exact state of the throttle arm was at the last inspection.

Text from the NTSB. Open the NTSB docket for CEN16LA227 for the full record.