Flight Sequence
The flight departed Nashville for Knoxville at 2000. At 2205, it departed Knoxville for the return trip to Nashville. At 2238, the pilot reported picking up light ice. For the next 10 minutes, the pilot continued to request lower altitudes until the aircraft was lost from radar.
Weather Briefing
Before departing Nashville, the pilot received weather information from a commercial weather service at flight operations. The content of this briefing could not be obtained. Later, at 1839, the pilot called Nashville AFSS (Automated Flight Service Station) for a weather update. There is no record of any weather briefings subsequent to the 1839 update.
Pilot Reports and Actions
At 2238, the pilot reported light ice. Over the next 10 minutes, the pilot repeatedly requested lower altitudes. The aircraft was then lost from radar.
Operational Culture
According to former pilots of the operator, pilots were routinely threatened with punitive action for refusing to fly in questionable weather conditions, or to fly aircraft with questionable airworthiness conditions.