Cessna 310 N5044J

The pilot was conducting an instrument flight rules flight along a route that he had flown frequently in the months before the accident. About 55 minutes into the flight, while at cruise altitude, the pilot stated to air traffic control, "I need to get on the ground immediately." The controller provided the pilot with the nearest airport information; however, no further intelligible radio transmissions were received from the pilot. Radar data showed the airplane enter a turning descent before radar contact was lost about 1.8 nautical miles from the accident site. A witness near the accident site heard engines revving up and down for about 1 minute and subsequently saw an airplane overhead. She reported that the engines were loud, and as the airplane flew by, she saw gray smoke trailing the airplane and a red/orange glow originating from under the right wing area. The airplane then flew out of view, and she subsequently heard a loud explosion and saw a plume of smoke. The distribution of the wreckage was consistent with a high-speed impact. Flight control continuity could not be established due to the heavy fragmentation of the wreckage; however, all major flight control components were located in the debris field. Examination of the engines revealed no anomalies or thermal damage that would have precluded normal operation. Both damage signatures and witness accounts indicated that the engines were producing power at the time of the accident. Autopsy findings were consistent with the pilot's inhalation of smoke/soot before the impact occurred. The wreckage also exhibited evidence of an in-flight fire. Small areas of broomstrawing and localized thermal damage were found on structures located in the left side of the cockpit area, where the pilot was likely seated. In addition, there was evidence of airflow-driven soot tailing on rivets in a few areas of the fuselage. The recovered instrument panel, wiring, and avionics showed no signs of electrical arcing or fire. Although the airplane's combustion cabin heater was not inspected in accordance with the latest airworthiness directive, the interior components of the heater showed no signs of fire. Based on this information, the heavy fragmentation of the wreckage, and the postcrash fire to which it was also exposed, the origin of the in-flight fire could not be determined. There was no record that the pilot accessed any weather products before or during the accident flight. The pilot likely encountered light to moderate icing conditions about 3 minutes after takeoff, which had been forecast by several products issued before the pilot's departure; however, these conditions deteriorated to moderate or greater turbulence and moderate or greater icing conditions, including supercooled large droplet (SLD) icing, during the final 10 minutes of the flight. These conditions were not forecast or reflected in pilot reports. The pilot did not state that he was accumulating airframe icing at any time during the flight, but it is likely that the SLD icing rapidly accumulated on the airframe to the extent that the airplane could no longer sustain flight. Although it could not be determined when the in-flight fire occurred it was likely the reason for the pilot stating he had to get on the ground immediately. Further, it is also likely that the SLD and the prevailing instrument meteorological conditions in the area reduced the likelihood that the pilot could have expediently performed an emergency descent and landing.

Quoted verbatim from the NTSB record.