What happened
Prior to departure, the pilot of a single-engine turbo-propeller aircraft failed to complete the entry of a flight plan into the integrated flight management system, intending to address the task during the flight. The aircraft departed without an instrument flight rules (IFR) flight plan and entered instrument meteorological conditions (IMC). After contacting air traffic control to request VFR flight following and an IFR clearance, the pilot spent much of the flight attempting to program, delete, and activate flight plan data. Cockpit voice recorder audio indicated the pilot experienced confusion and frustration regarding navigation fixes and the flight management system during the final stages of the flight.
As the pilot focused on the flight management system and adjusting altimeter settings, the aircraft's pitch increased to 10 degrees nose up, causing the airspeed to drop to 109 knots. This decay triggered the stall warning system and disconnected the autopilot. The aircraft entered a series of turns before entering a steep, descending right turn that ended in an impact with the ocean approximately 3 miles from the coast. During the final 150 seconds of flight, the aircraft issued multiple stall warnings, stick shaker activations, and terrain avoidance alerts. There was no evidence of mechanical failure in the recovered wreckage.
Findings
- The pilot's preoccupation with the flight management system led to a failure to monitor airspeed.
- The aircraft entered an aerodynamic stall due to the loss of airspeed and improper pitch attitude.
- The presence of IMC likely contributed to the pilot experiencing spatial disorientation.
- The pilot was unable to recover control of the aircraft following the stall and autopilot disconnection.