Accident Sequence
The accident occurred while the pilot was cruising on a scheduled cargo flight in instrument meteorological conditions (IMC). The pilot encountered moderate to severe turbulence near an area where weather cells could have been observed on the aircraft's radar. The pilot reversed course, declared an emergency, and subsequently lost control of the aircraft. The aircraft entered an uncontrolled descent, collided with terrain, and was destroyed. The pilot, who was the sole occupant, was killed.
Pilot Background and Training
The pilot had recently been hired and had completed the FAA-approved ground and flight training program for the aircraft. However, during the pilot's recent training, neither the FAA nor the operator required the pilot to demonstrate proficiency in unusual attitude recoveries or to have knowledge in the operation of the aircraft's weather radar.
Employee Statements
Company employees, including the pilot's husband, stated that the pilot had no previous experience with weather radar and did not understand the weather radar installed in this aircraft. They further stated that the pilot appeared to be tired.
Investigation Findings
The investigation identified several contributing factors. The flight took place on a dark night. Weather conditions included turbulence in clouds. The pilot did not understand the weather radar. There was inadequate initial training provided by both the company/operator management and the FAA (principal operations inspector). The pilot continued flight into known adverse weather. During the maneuver to reverse direction, the pilot experienced an uncontrolled spiral, spatial disorientation, and fatigue (lack of sleep).
Probable Cause
The National Transportation Safety Board determined the probable cause to be the pilot's encounter with severe turbulence, which precipitated a loss of aircraft control.