Accident Overview
An airplane conducting an instrument flight rules (IFR) flight departed with clearance to its destination airport. The pilot requested and received clearance for an RNAV (GPS) approach. While descending through 3,500 ft mean sea level (msl), air traffic control instructed the pilot to cancel the IFR clearance and approved a radio frequency change. No further communication was received from the pilot; radar contact was lost when the airplane reached 2,000 ft msl, consistent with normal approach operations.
Flight and Weather Conditions
The airplane came to rest in an open pasture approximately 1.5 miles from the destination airport. Low IFR (LIFR) conditions were forecast for the area, and National Weather Service forecasts matched the weather encountered during the approach.
Passenger Account
The sole surviving passenger reported that the airplane was off course during the approach and that the pilot struggled to regain the correct path. The passenger recalled hearing a warning alarm multiple times, followed by the airplane “aggressively pitching up” with additional alarms, then “aggressively pitching down.” He observed the pilot pulling hard on the yoke and believed he heard the copilot call for the pilot to raise and straighten the nose. The passenger stated he could not see outside due to clouds and fog until just before impact.
Autopilot and Flight Control Data
Data from the airplane’s autopilot indicated that the pilot began the approach with the autopilot engaged. About 1 mile from the runway and 500 ft above airport elevation, the pilot initiated a right climbing turn and disconnected the autopilot. This action was consistent with executing a missed approach procedure. During the climbing turn, the airplane’s pitch increased to as high as +20° and roll to +47° (right). These angles suggested the pilot likely had difficulty controlling the airplane. The pilot then engaged the autopilot’s unusual attitude recovery mode. The autopilot made inputs to return to level flight, but the pilot made conflicting control inputs. The airplane entered a brief descent followed by a rapid climb. Indicated airspeed at the top of the climb was 16 knots, well below stall speed for any flap configuration. The airplane likely entered an aerodynamic stall followed by a rapid descent to impact. The airplane impacted the ground at a shallow pitch angle, suggesting the pilot may have attempted a stall recovery maneuver, but altitude was insufficient for full recovery.
Postaccident examination of the airframe, engine, and autopilot revealed no anomalies.
Toxicological Findings
Toxicology testing detected trace levels of pheniramine, naltrexone, naltrexol, and CBD in the pilot’s system. The report stated that, although the pilot had used these substances, his performance was not likely impaired at the time of the accident. In the copilot’s heart blood, meclizine was detected at a level making it reasonably likely he experienced some effects of this medication. However, whether such effects impaired his performance in a way that contributed to the accident is unknown, especially given his uncertain role and the presence of the other pilot. The copilot also had used cetirizine, but it was not detected in his blood, so it was not likely causing impairment at the time of the accident.
Probable Cause
The official probable cause of the accident was the pilot’s spatial disorientation during a missed approach in instrument meteorological conditions, which led to an exceedance of the airplane’s critical angle of attack and a subsequent aerodynamic stall.