Midwest Executive

Beechcraft E18

The pilot received a weather briefing before starting a night cargo operation in known icing conditions. Before the flight, a line serviceman noticed ice on the aircraft's wings and suggested its removal, but the pilot declined. Approximately 45 minutes after takeoff, the pilot reported to ARTCC that a de-ice boot had 'blown' and he was having difficulty controlling the aircraft. He said the boot was 'going back and forth' and that full right aileron was required to keep the wings level. Also, he reported a continuous loss of altitude and said that full right aileron would not keep the aircraft from turning to the left. Subsequently, the aircraft crashed on descending terrain while in a slightly nose down, left wing low attitude. Much of the aircraft (including much of the left wing) was demolished by impact and fire. Prop slash marks indicated the engines were providing power. Maintenance records had no information of replacement, repair or modification of the de-ice boots in the previous 10 years. The pilot's wife indicated he had previously been pressured to fly aircraft with discrepancies. Sigmets golf 3 and 4 warned of occasional severe mixed icing in clouds and precipitations. Both occupants were killed.