Schleicher ASW-19 N438AS accident near Dansville, New York

Probable cause

The pilot’s failure to maintain glider control while maneuvering. Contributing to the accident was the pilot’s impairment due to an over-the-counter sedating antihistamine.

NTSB analysis

During the evening before the accident, the glider was assembled, and the pilot flew it for about 30 minutes uneventfully. On the day of the accident, after flying locally for about 3 hours, the glider was about 1 mile from the departure airport when witnesses reported that the glider started rolling back and forth into 90-degree banks. After three or four rolls, the glider descended nose-down to the ground and impacted a field in a flat attitude. Examination of the wreckage did not reveal any preimpact mechanical malfunctions that would have precluded normal operation.

About 3 years before the accident, the pilot underwent a procedure to repair an aneurysm of the ascending aorta combined with placement of a single vessel coronary artery bypass graft. He subsequently received a medical certificate and reported the surgery and that he was taking metoprolol (a beta blocker used to treat hypertension and prevent heart attacks), simvastatin (a cholesterol lowering drug), and lisinopril (a blood pressure medicine). Although the pilot's medical certificate had expired about 1 month before the accident, he was not required to possess a current medical certificate as a glider pilot. Before the accident flight, the pilot remarked to a friend that he was not feeling well. The friend added that the day was very hot and that the pilot did not drink water before the flight or bring any water with him. Autopsy results indicated that there was no evidence to suggest any direct effect of the pilot's cardiovascular disease (heart attack) in his ability to control the glider.

Toxicological testing revealed levels of diphenhydramine in the pilot's blood that were well above therapeutic levels. Diphenhydramine is a sedating antihistamine used to treat allergy symptoms and as a sleep aid. It is probable that the cognitive and psychomotor impairment caused by diphenhydramine contributed to the pilot's loss of control in this accident.

Text from the NTSB. Open the NTSB docket for ERA12LA528 for the full record.