What happened
While performing an instrument approach at night, the pilot of a twin-engine turboprop aircraft reported that one of the engines had failed, though the specific engine was not identified. Approximately nine seconds after this report, the aircraft struck the ground roughly one-quarter mile before reaching the runway. A significant fire broke out following the impact, destroying much of the wreckage.
During the final nine seconds of the flight, the aircraft's groundspeed decreased from 99 knots to 88 knots, while the plane descended approximately 400 feet during a slight turn to the left. Because the aircraft's minimum controllable airspeed was 92 knots, the drop in speed contributed to a loss of control. Evidence at the crash site, including a left-wing-low impact pattern, supported the conclusion that the aircraft became uncontrollable just before hitting the terrain.
Findings
An inspection of the left engine revealed that a single blade had separated from the midspan of the first-stage turbine rotor. While the fracture surface showed oxidation, investigators could not confirm if this separation happened during the accident flight or a previous one. The left engine also showed signs of long-term degradation, including high temperatures in the second-stage turbine and thermal damage to the second-stage turbine stator assembly. While these issues reduced the engine's performance, they were not sufficient to cause a total loss of power.
In contrast, the right engine showed no signs of anomalies that would have prevented normal operation. Investigators noted that neither propeller was in the feathered position, which is the required procedure for an engine failure according to the pilot operating handbook. Had the pilot properly secured the left engine and feathered the propeller while increasing power to the right engine, the aircraft likely would have had enough performance to reach the runway safely.