Cessna 172N N75558 accident near Mcmurray, Washington

Probable cause

The pilot's improper decision to continue VFR flight into instrument meteorological weather conditions. Contributing to the accident were low ceilings, reduced visibility, and mountainous terrain.

NTSB analysis

The instrument rated commercial pilot departed under visual flight rules (VFR) for a planned cross-country flight. Shortly after departure, the pilot was receiving radar flight following for about 15 minutes. During this time, the controller advised the pilot that no one had successfully proceeded south VFR and that low ceilings and reduced visibility existed between her destination and her point of departure. Radar data revealed that the flight was initially on a southeasterly heading at an altitude of about 2,400 feet. About 18 minutes after departure, the flight initiated a descent to 900 feet while remaining on the southeasterly heading. As the flight approached an uncontrolled airport, radar data showed a slight climb to 1,400 feet, followed by a climbing 180-degree turn to the northwest, which was opposite the direction of her intended destination. Two minutes later the flight initiated a right turn to a northerly course, while continuing to climb. As the flight proceeded northward, radar data depicted a series of turns to the left and right with the altitude fluctuating between 1,500 feet and 2,900 feet before radar contact was lost. Wreckage and impact signatures were consistent with the airplane impacting trees and mountainous terrain at 2,250 feet msl within a heavily wooded area on an easterly heading. All major components of the airframe were located at the accident site. Review of recorded weather data revealed that instrument meteorological conditions prevailed in the area at the time of the accident, with restricted visibilities in rain showers, and overcast clouds with bases and tops at 1,900 and 10,000 feet, respectively. Examination of the recovered airframe revealed no mechanical anomalies that would have precluded normal operation. Examination of the engine revealed that the number four cylinder exhaust valve was stuck in the open position and was bent. The camshaft was intact and each of the camshaft cam lobes exhibited severe wear and spalling signatures. The corresponding tappets exhibited severe spalling on their respective camshaft contact surfaces. The engine exhibited signatures consistent with a high time engine.

Text from the NTSB. Open the NTSB docket for LAX08FA246 for the full record.