The airplane was destroyed and the Commercial pilot aboard was fatally injured on impact with terrain while on approach to the James M. Cox Dayton International Airport. Instrument conditions prevailed; the Part 135 cargo flight originated from the McGhee Tyson Airport in Knoxville, Tenn. According to an initial review of ATC voice and radar data, the airplane was at 5000 feet, when the pilot contacted Dayton Approach at 0121. At 0135, the pilot was vectored to intercept the Runway 6L localizer, and was cleared for ILS Runway 6L approach. The airplanes last radar target was observed at an altitude of 1200 feet msl, and a groundspeed of 130 knots. The airplane impacted trees and came to rest inverted on airport property, on a bearing of 053 degrees, and a distance of mile to the runway.Subsequently, the pilot of another PA-31-350 operated by the same company who landed on Runway 6L shortly before the accident, reported that he observed the approach lights at an altitude of about 300 feet but did not see any sequenced flashing lights, and noted that the approach lights were all solid. A post-accident check of the lighting system revealed that 2 of the 15 sequence flashing lights were not operating. In addition, four random steady lights were also not working.