Cessna P210N accident near Santa Monica, California, August 11, 2012

The NTSB's narrative final · quoted from the NTSB record

About 15 minutes after departure, the pilot contacted air traffic control and requested a return to the departure airport without indicating the reason. About 10 minutes later, the pilot was instructed to enter a right base leg for the runway and was subsequently cleared to land behind traffic. One minute later, the pilot declared an emergency, but he did not identify the nature of the emergency. No further transmissions were made by the pilot. The airplane then collided with treetops on a southeasterly heading about 3 miles northeast of the airport and continued about 200 feet before striking the top of a palm tree and falling to the ground. A postcrash fire consumed the majority of the airplane. Postaccident examination of the airframe revealed no mechanical anomalies that would have precluded normal operation. The engine spark plugs were covered in heavy, dark soot indicative of an extremely rich mixture condition, which could have resulted in a loss of engine power. The engine was examined and subsequently placed on a test stand. After repairs were made to facilitate an engine run, the engine started, ran, and responded to throttle movements with no discrepancies noted. The reason for the return to the departure airport and subsequent reported emergency could not be determined. The investigation found that the pilot may have had therapeutic levels of doxylamine, a sedating antihistamine, in his blood about the time of the accident. However, based on the circumstances of the accident, it is unlikely that pilot impairment from doxylamine contributed to the accident. Further, the carbon monoxide present in the pilot's blood is consistent with postaccident exposure to combustion products.

The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.