The aircraft was on an air taxi flight to transport 2 prisoners and was to be operated on a VFR flight plan in VFR conditions only. Prior to takeoff, the pilot had obtained 12 weather briefings. In 2 of the briefings, VFR flight was not recommended. At about 1338, he departed from Winston-Salem in VFR conditions on a flight to Knoxville, TN. Witnesses, south of the crash site, reported seeing the aircraft heading north near Interstate Highway I-77. They reported the engine was steady and loud. One witness stated that the plane was flying at about 200 ft AGL, well below the mountains ahead. Reportedly, there was fog in the area and the higher elevations were completely obscured by fog. One or two minutes later they heard the crash. An investigation revealed the plane had impacted the side of a mountain while in level flight, then burned. No evidence of preimpact malfunction/failure or foul play was found. The pilot had recently been hired and this was only his second flight as pilot-in-command with this company.