History of Flight
On December 4, 2021, at about 1840 Pacific standard time, a Beech V35, registration N7933M, was substantially damaged when it impacted terrain near Visalia, California. The pilot and three passengers were fatally injured. The flight was conducted under Title 14 Code of Federal Regulations Part 91 as a personal flight.
Recorded ADS-B data from the Federal Aviation Administration showed that the airplane departed runway 30 at 1837:01 and climbed to 495 ft mean sea level (msl) before entering a left turn. At 1837:26, it continued climbing in the left turn to 620 ft msl, then began descending. The descent continued in the left turn until ADS-B contact was lost at 1837:37 at an altitude of 395 ft msl, about 660 ft northwest of the accident site. The airport elevation was 295 ft msl.
A witness in a residence near the accident location reported hearing an airplane flying very low, followed by the sound of impact. The engine noise was constant and did not sound like it was malfunctioning. She notified first responders.
Personnel Information
Review of the pilot’s logbook indicated he completed an instrument proficiency check on March 24, 2021. In the 12 months preceding the accident, he accumulated about 4 hours of simulated instrument flight, 0.4 hours of actual instrument flight, and about 1 hour of night flight.
Meteorological Information
At 1830, the Visalia Municipal Airport automated weather observation recorded wind from 280° at 5 knots, visibility 2½ miles, mist, broken ceiling at 300 ft agl, temperature 8°C, dew point 8°C, and altimeter 30.24 inches of mercury. An AIRMET SIERRA advisory for instrument flight rules conditions was issued at 1245 and was valid at the time of the accident, indicating ceilings below 1,000 ft, visibility below 3 statute miles, mist, and fog. No air traffic control services were provided to the pilot during the accident flight.
Wreckage and Impact Information
The airplane struck a flat, open wheat field about 1 mile southwest of the departure end of runway 30. It came to rest on its left side, on a heading of about 265° magnetic, at an elevation of 290 ft msl. The first point of contact was a ground scar approximately 14 ft long, 22 inches wide, and 3 inches deep. The debris field extended about 345 ft to the main wreckage on a magnetic heading of 105° and was 200 ft wide. The propeller and hub were found about 15 ft from the initial impact point.
Flight control continuity was established from the cockpit to all primary flight controls. Numerous separations within the flight control system were consistent with overload separation or recovery personnel actions. No preaccident mechanical failures or malfunctions were identified that would have precluded normal operation.
Medical and Pathological Information
An autopsy performed by the Tulare County Coroner's Office determined the pilot’s cause of death as blunt trauma. Toxicology testing at the FAA Forensic Sciences Laboratory detected ethanol in the pilot’s liver (0.402 gm/hg), kidney (0.045 gm/hg), and muscle tissue (0.035 gm/hg); however, another laboratory did not detect ethanol in muscle tissue. Isopropanol was detected in liver tissue at 0.009 gm/hg. The non-impairing cholesterol medication atorvastatin was also detected in liver and muscle tissue.
Additional Information
The FAA Civil Aeromedical Institute's publication "Introduction to Aviation Physiology" defines spatial disorientation as a loss of proper bearings or mental confusion as to position, location, or movement relative to the earth. Factors contributing to spatial disorientation include changes in acceleration, flight in instrument flight rules conditions, frequent transitions between visual and instrument flight rules, and unperceived changes in aircraft attitude. The FAA’s Airplane Flying Handbook (FAA-H-8083-3B) notes that the vestibular sense can confuse pilots, causing false sensations that lead to spatial disorientation.