Piper PA22-150 N7402D accident near Girdwood, Alaska

Probable cause

The pilot's failure to maintain clearance from terrain due to his impairment from alcohol consumption.

NTSB analysis

The airline transport pilot was conducting a local flight with three passengers over an area that comprised remote, mountainous terrain. One witness saw the airplane performing aggressive maneuvers earlier in the flight, and observed the airplane approached a ridge, its nose pitched up and the airplane entered a steep climb before disappearing from view. Multiple witnesses saw the airplane flying parallel to a mountain ridge before it entered a turn and began a descent. The airplane then disappeared from view followed by a plume of black smoke. None of the witnesses reported hearing any unusual sounds from the accident airplane before the accident.

Toxicological testing of the pilot detected 0.226 gm/dl ethanol in the femoral blood, which is greater than 5.5 times the regulatory limit for pilots. The concentration of ethanol in the pilot's vitreous fluid compared to femoral blood was consistent with the recent ingestion of alcohol. It is likely that at these levels the pilot experienced not only degradation of judgment, but mood and behavioral changes, altered perception of the environment, and deficits in coordination, psychomotor skills, and attention.

Although the airplane was not recovered from the accident site and could not be examined, the circumstances of the accident are consistent with the pilot's failure to maintain clearance from terrain while maneuvering due to the impairing effects of his recent alcohol consumption.

Text from the NTSB. Open the NTSB docket for ANC19FA042 for the full record.