Beech G33 N9345Q accident near Warsaw, Ohio

Probable cause

The pilot's decision to continue flight in known icing conditions, which resulted in structural icing, degraded airplane performance, and a subsequent loss of control. Contributing to the accident was the pilot's failure to obtain an official weather briefing before departure.

NTSB analysis

The commercial pilot departed on an instrument flight rules cross-country flight in the single-engine airplane that was not certificated for flight in icing conditions. During cruise flight at 4,000 ft mean sea level (msl), the pilot reported to air traffic control that the airplane was accumulating airframe icing and requested and was cleared to descend to 3,000 ft msl. As the airplane descended, the pilot indicated to the controller that the airplane had descended below the clouds, was in temperatures greater than 32°F, and that the airframe icing was "clearing up"; however, the airplane continued to descend and subsequently impacted terrain. First responders discovered pieces of ice at the accident site that displayed a curvature consistent with the leading edge of a wing or horizontal stabilizer. Examination of the airframe and engine did not reveal any preimpact anomalies that would have precluded normal operation of the airplane.

There was no evidence that the pilot received an official weather briefing before the flight, which would have indicated the potential for moderate or greater icing conditions between 3,000 and 15,000 ft msl. It could not be determined if the pilot received any weather information from other sources. Review of additional weather information indicated the possibility of supercooled large droplet (SLD) icing in the area of the accident site about the time of the accident.

It is likely that the structural icing accumulated during the flight resulted in the pilot's inability to maintain airspeed and/or altitude, leading to a loss of control.

Text from the NTSB. Open the NTSB docket for CEN18FA143 for the full record.