This September 2009 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.
Aircraft: Cessna 206. Injuries: 4 Serious. Location: Truckee, Calif. Aircraft damage: Substantial.
What reportedly happened: Witnesses reported observing the airplane take off from the runway and enter a left turn. One witness, a pilot, stated that the airplane was climbing about 100 feet per minute or less during takeoff. It appeared that the pilot was executing the left turn noise abatement departure procedure and had completed an estimated 270° left turn.
The witness said that as the airplane was “in line with runway 28,” he observed the left wing drop about 40° to 60°, followed by a “partial recovery,” before entering a “knife edge” and descending toward the ground. The passenger seated in the right front seat reported that during takeoff initial climb the airplane suddenly pitched upward. The passenger said the pilot leveled the airplane and the right wing dipped. As the pilot leveled the airplane a second time, the left wing dipped and the airplane hit the ground and nosed over.
Examination of the accident site by FAA inspectors revealed that the airplane crashed in an open field adjacent to the airport. Examination of the recovered wreckage revealed that impact signatures on the nose, wings, and fuselage were consistent with a stall and/or spin.
No evidence of any pre-impact mechanical anomalies was discovered with the engine or airframe.
Review of data obtained from a handheld global positioning system that was recovered revealed that the airplane initiated a left climbing turn after takeoff. The data showed that, during the climb, the GPS ground speed fluctuated between 77 and 92 miles per hour. The last recorded GPS data track point indicated a speed of 89 miles per hour. Using reported and estimated weights of the pilot and three passengers, aircraft empty weight, full fuel, and the weight of the baggage removed from the airplane, the airplane was within center of gravity and maximum gross weight limitations. Testing of the stall warning system revealed contamination in the switch that resulted in intermittent performance of the system.
Probable cause: The pilot’s failure to maintain adequate airspeed for flight, which resulted in an aerodynamic stall and subsequent impact with the ground. Contributing to the accident was the intermittent failure of the stall warning system due to a contaminated switch.
For more information: NTSB.gov. NTSB Identification: WPR09LA432