ERA17FA139 · Mooney M20J

The airline transport pilot of the single-engine airplane was departing on a cross-country flight in dark night, visual meteorological conditions over sparsely lighted terrain. GPS and radar information showed that, shortly after takeoff, the airplane turned about 5° left during its initial climb over the runway before beginning a climbing right turn consistent with a direct heading toward the destination. The airplane continued the right turn past the on-course heading and entered a descent, which continued until impact with terrain about 2,500 ft from the departure end of the runway. The wreckage path orientation was consistent with a steep, powered descent and impact with terrain in a right descending turn. Examination of the wreckage revealed no evidence of any preimpact mechanical failures or malfunctions of the airframe or engine.

It is unlikely that the pilot's high blood pressure or its treatment contributed to the accident and there is no evidence to suggest that he was suddenly impaired or incapacitated by his moderate coronary artery disease. Overall, it is unlikely that the pilot's medical conditions or use of medications contributed to the accident. The dark night conditions and sparsely-lighted terrain in the vicinity of the airport combined with the pilot's high cockpit workload during takeoff into instrument meteorological conditions, may have been conducive to the development of spatial disorientation; however, there is insufficient evidence to determine whether disorientation may have contributed to the accident.

Verbatim NTSB analysis and probable cause from the NTSB dataset