Cessna 150G N3875J accident near Rhine, Georgia

Probable cause

The student pilot's decision to take off from a partially-lit grass runway in dark night, marginal visual flight rules conditions, which resulted in spatial disorientation, an exceedance of the airplane's critical angle of attack, and an aerodynamic stall.

NTSB analysis

The student pilot departed in dark night, marginal visual flight rules (MVFR) conditions from his private grass runway that was partially lit with solar lights. A witness heard the airplane depart followed by the sound of a crash, and when he arrived at the airstrip, he observed a light layer of fog over the runway. The airplane came to rest in heavily-wooded terrain adjacent to the runway. Examination of the airplane and engine revealed no anomalies that would have precluded normal operation before impact.

Data downloaded from an onboard GPS unit revealed that, after departure, the airplane made a climbing right turn to an altitude of 407 ft. It then descended to 256 ft and reached a maximum airspeed of 95 knots (kts) while continuing the right turn. The airplane then climbed in a right, 30° bank to a maximum altitude of 666 ft while slowing to an airspeed of 32 kts, which was well below the minimum stall speed. The airplane then rolled to the right and entered a rapid descent before the data ended.

Conditions conducive to the development of spatial disorientation were present, including the dark night, MVFR conditions and a noninstrument-rated student pilot. Additionally, the airplane's track data, which reflects spiral-like maneuvering, and a wreckage distribution consistent with a loss-of-control, stall-type vertical descent, are consistent with the known effects of spatial disorientation. Based on this evidence, the student pilot most likely experienced spatial disorientation after takeoff, which led to the airplane exceeding its critical angle of attack and an aerodynamic stall.

Text from the NTSB. Open the NTSB docket for ERA17FA330 for the full record.