What happened
The aircraft struck the ground in a steep, nose-down attitude at high speed. The accident occurred approximately 8 miles east of the flight's intended destination airport. No flight plan had been filed for this personal flight, and there were no records of an FAA preflight weather briefing or any en route communications with FAA facilities. At the time of the accident, a deputy sheriff patrolling near the site reported heavy rain and wind, while local residents reported experiencing strong winds, heavy rain, lightning, and thunder.
The investigation
Examination of the wreckage revealed no evidence of a preimpact mechanical malfunction or failure. Weather data analysis showed that an unusually strong late fall weather system was affecting the area. Overcast clouds were banked over the Sierra-Nevada foothills, consisting of a southwest-northeast oriented cloud band with scattered light rain showers. Cloud bases were estimated between 1,000 and 2,000 feet above ground level, with tops around 16,000 feet MSL. At the aircraft's estimated flight altitude of 3,000 to 4,500 feet MSL, winds were southwesterly at 30 knots and temperatures ranged from 34 to 41 degrees Fahrenheit. The freezing level was approximately 5,000 feet MSL. Due to the presence of light rain showers and upslope flow, supercooled large water droplets were likely present in the area.
Findings
- There were no known witnesses to the accident.
- The aircraft's flight was conducted without a filed flight plan or weather briefing.
- Conditions included potential for moderate to severe mixed icing above 5,000 feet MSL.
- Occasional moderate turbulence was likely in the area.