Aircraft: Beech Bonanza. Injuries: 2 Fatal. Location: Chester, Calif. Aircraft damage: Substantial.
What reportedly happened: The 76-year-old private pilot was attempting to land at his home airport at night. The airport is located on the outskirts of a town, adjacent to a lake and a sparsely populated national park. The moon was low on the horizon and behind the airplane during the crosswind and downwind turns. The pilot’s forward view would also have been dominated by a dark void as the airplane passed over the town and began the landing approach.
The en route portion of the flight radar data revealed a flight track consistent with the pilot hand flying the airplane at altitudes appropriate for the terrain elevation. Based on witness reports, the airplane appeared to perform a normal crosswind approach over a town and toward the airport runway.
During the approach, the pilot made a normal radio call and did not appear to be in distress. As the airplane rounded the turn from crosswind to final, it continued in a shallow, high-speed descent, crashing directly into the frozen surface of a lake adjacent to the runway.
The debris field was on a heading which approximated the downwind segment of the landing runway. The landing gear and flaps were not in the landing configuration, and the speed brakes were not deployed. The damage to the propeller was consistent with the engine producing power at the time of impact. The pilot did not possess an instrument rating, which, coupled with the lighting conditions, could have made him vulnerable to spatial disorientation. The airplane’s impact trajectory was consistent with him encountering this phenomena.
Six years prior to the accident the pilot had a mild heart attack with placement of stents in two coronary arteries, and a diagnosis of diabetes. However, he had denied any medical history in applications for FAA medical certificates. Investigators stated that it was not possible to conclusively determine what role, if any, the pilot’s unreported medical conditions played in the accident.
Probable cause: The pilot’s loss of control while maneuvering to land, most likely due to spatial disorientation.
NTSB Identification: WPR11FA090
This January 2011 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.