Amateur-built BG-12B N559Y accident near Moore, Idaho

Probable cause

The pilot’s decision to perform a low pass over the runway in the opposite direction of his intended landing, and his subsequent failure to maintain airspeed and glider control during the reverse-course maneuver. Contributing to the accident was the effect of the pilot's failure to take his prescribed medications.

NTSB analysis

The pilot of the experimental amateur-built glider was returning to land after a 2-hour flight. Witnesses located on the airfield were startled as the glider flew inbound with a tailwind 75 feet over the runway at a high speed. The glider then began a smooth pitch up and a wingover-type maneuver in a presumed effort to return for landing. During the maneuver, the glider stalled and spun to the ground. The pilot had arrived at the airfield earlier in the week for a fly-in, and had flown the glider uneventfully twice since arriving. Witnesses, who were also friends of the pilot, expressed astonishment that he performed the low pass and wingover maneuver, stating that such a flamboyant maneuver was completely out of character.

The pilot purchased the vintage glider about 4 years before the accident, and the fly-in was the first time he had flown it. He held a commercial pilot certificate for gliders and powered airplanes, and had accumulated extensive experience flying hang gliders and paragliders. Additionally, he owned a modern glider, which would have had markedly different performance characteristics than the accident glider.

Although the most recent condition inspection had been performed on the glider 4 years before the accident, examination of the wreckage did not reveal any anomalies with the airframe that would have precluded normal operation.

About 2 years before the accident (and after his most recent FAA medical certificate application), the pilot’s personal physician described signs of depression, including mood swings, elevated mood, compulsive behaviors, obsessive thoughts, and poor insight. As such, he prescribed medication to control these conditions, as well as medication for hypertension, which had been diagnosed previously. About 6 months before the accident, the pilot was also diagnosed with and prescribed medication for hyperlipidemia; he was still under treatment for prior diagnosed conditions. At that time the physician noted that his depression was under “fair control.” However, postmortem toxicological analysis revealed that he had not been taking any of his prescribed medications at the time of the accident. As such, it is possible that he was experiencing symptoms of his medical conditions, including compulsive behavior, at the time of the accident. Although the pilot’s judgment could have been affected by the symptoms of hypoxia or dehydration, it was not possible to determine if he was experiencing these conditions.

Text from the NTSB. Open the NTSB docket for WPR11FA392 for the full record.