Piper PA-18-135 N1123 accident near Willow, Alaska

Probable cause

The pilot's failure to maintain clearance from a tree due to the effects of impairment from alcohol consumption.

NTSB analysis

The flight departed a private airport about 3 miles south of the accident site. A witness reported seeing the airplane approaching at a low altitude. The witness observed the airplane's left wing strike a tree about 100 feet from his location. The airplane continued and passed overhead, crashing in a wooded area behind him. The witness recalled that the airplane's engine sounded as though it was producing power and that the airplane maintained level flight. The accident site was on a broad, flat expanse of tree-covered land. The airplane impacted a single tree located between the parking area and the park administration building; the top 8 feet of the 50-foot-tall tree was severed. The airplane subsequently impacted additional trees and terrain at the rear of the building. An examination of the airplane revealed no evidence of any preimpact mechanical malfunctions or failures. Within the wreckage, an open container of beer was found located in the cockpit at the base of the pilot's seat.

Toxicological testing performed on the pilot's specimens detected 106 (mg/dL, mg/hg) ethanol in the blood, which is equivalent to a 0.106 percent blood-alcohol level. He had slightly higher vitreous and urine alcohol levels, consistent with the recent ingestion of alcohol and with impairment due to that ingestion.

A review of law enforcement records revealed that the pilot had two alcohol and driving related convictions in 1994 and 1996. After the second conviction, the Federal Aviation Administration (FAA) requested that this pilot undergo psychiatric and neuropsychological evaluations, which did not formally result in a diagnosis of substance abuse or dependence, but noted that having the convictions gives an indication that the pilot does have problems with drinking and that alcohol consumption is an area of potential danger for him. Despite these concerns, the FAA issued a medical certificate to the pilot without any further follow-up required.

Text from the NTSB. Open the NTSB docket for ANC10FA038 for the full record.