Sonoma County Airport
Aircraft Accident/Incident Report

Santa Rosa, California 95448
Wednesday, October 4, 2000 9:31 PDT

During initial climb in instrument meteorological conditions, the pilot failed to maintain directional control and altitude. The airplane entered a right descending spiral until impacting terrain 2 miles west of the airport. In accordance with the instrument departure procedure, the pilot had taken off from runway 19, elevation 125 feet msl, under a 600-foot overcast sky condition. Thereafter, the pilot commenced a right climbing turn. The pilot reported climbing through 1,100 feet and 1,600 feet msl, and the radar controller informed the pilot that he was not receiving the airplane's mode C transponder signal. The radar controller then observed one radar hit and then lost contact with the airplane. All recorded radar data from the area around the airport at the time of the accident was reviewed. The FAA indicated that this location had only one long-range radar site that covered the area below 5,000 feet. When the recorded radar data was filtered to search for targets within a 10 nm radius around the airport and up to 5,000 feet, the subject airplane was only observed one time on a transponder code of 3311. The target had an invalid Mode C code at that time, with no radar reinforcement. The approximate distance and bearing from the end of runway 19 to this first radar hit, was 2.3 nm and 261 degrees, magnetic. The approximate distance and bearing from the radar hit to the crash site was 0.6 nm and 042 degrees, magnetic. Based upon a subsequent examination of the radar data showing all targets, three additional non Mode C transponder (primary) targets were located. The positions of these targets were noted southwest of the airport, at the following times: 0929:22, 0929:58, and 0930:22. The calculated ground speed between these hits and the previously identified Mode C target was, respectively, 75, 131, and 163 knots. During the subsequent airframe and engine examination, no evidence of any mechanical failure or malfunction was found. However, neither the artificial horizon nor the directional gyroscope were recovered from the 50-foot deep pond. During the wreckage examination, the airframe was found accordioned in an aft direction, and the wings were fragmented. Evidence was found that could document the pilot's instrument flying currency and familiarity with the make and model airplane.

the pilot's loss of airplane control due to spatial disorientation. A related factor was the low ceiling.