114 N4775W accident near Laughlin, Nevada

Probable cause

A partial loss of engine power due to the turbocharger's seizure as a result of a severely worn turbowheel. Contributing to the accident was the failure of the pilot/owner to have the turbo normalization system inspected every 100 hours as required, which allowed erosion on the exhaust side of the turbowheel to go undetected.

NTSB analysis

The private pilot/owner reported that, during the climb to between about 300 and 400 ft above the ground, the engine started running roughly, and the airplane was not accelerating or climbing. The terrain ahead was rising, so the pilot turned right. Due to the low altitude and reduced engine power, the pilot chose to conduct an off-airport landing, during which he attempted to troubleshoot the engine issue without success. As the airplane continued to descend, the pilot saw houses and bushes ahead; he aimed the airplane away from the houses, and the airplane eventually hit trees and terrain about 4.6 nautical miles from the airport. A postimpact engine fire ensued.

Postaccident examination of the engine revealed that the turbocharger was seized and that the exhaust side of the turbowheel was severely eroded, which led to the engine running rough. A review of the airplane's maintenance records revealed that a turbocharger normalization system had been installed on the airplane under a supplemental type certificate (STC) 13 years before the accident. The STC's instructions for continued airworthiness required that the turbocharger normalization system be inspected every 100 hours. However, a review of the airplane's maintenance records revealed that the system had only been inspected once since its installation and that the inspection was completed 6 years before the accident. No other abnormalities were noted with the airframe or engine that would have precluded normal operation. It is likely that the eroded turbowheel would have been detected if the turbocharger normalization system had been inspected as required.

Text from the NTSB. Open the NTSB docket for WPR15FA163 for the full record.