What happened
During a short cross-country flight, the pilot of a twin-engine airplane encountered instrument meteorological conditions. While cruising at 3,000 feet MSL, the pilot notified air traffic control that the aircraft was accumulating ice and expressed a need to increase speed. In an attempt to escape the icing, the controller authorized a descent followed by a climb. Shortly after these maneuvers, the controller issued a low altitude alert. Although the pilot reported that the aircraft was climbing, radar and radio communication were lost shortly after this exchange.
The aircraft subsequently struck a field approximately 7 miles from its destination airport. Due to the high level of fragmentation in the wreckage, the post-crash investigation of the airframe and engines was limited, though no mechanical anomalies were identified prior to the impact. The investigation noted that the pitot-static and deicing systems sustained damage too extensive for functional testing.
Findings
Data retrieved from onboard avionics revealed that as the pilot reported icing, the indicated airspeed began to deviate from the calculated ground speed. Eventually, the indicated airspeed dropped to zero while the ground speed remained relatively stable. This discrepancy suggests that icing of the pitot probe caused erroneous airspeed readings.
During the final two minutes of the flight, the aircraft was engaged in a left turn. The flight crew encountered multiple "SINK RATE" and "PULL UP" warnings as the aircraft performed a series of climbs and descents. During these maneuvers, the ground speed and likely the true airspeed reached or exceeded the aircraft's structural and maneuvering speed limits. It is believed the pilot was distracted by the incorrect airspeed information, leading to a loss of control during flight.