The flight departed the Columbia, South Carolina airport on an IFR flight plan to Greer, South Carolina. The weather at the time was VFR. The pilot did not report any problems to air traffic control prior to the crash, and all radio conversation with the pilot was normal. Radar data showed the aircraft climbed to 4000 feet and leveled off at that altitude for a brief period. The aircraft then began a shallow descent and disappeared from the radar. The pilot did not respond to radio calls after the descent began. The aircraft crashed into a residential area about nine miles from the Columbia airport. The wreckage was distributed over an area about 300 feet in length. There was no evidence of malfunction of the aircraft flight controls or catastrophic engine failure prior to the crash. Witnesses reported the aircraft was in a nose down attitude of about 30 degrees prior to the impact. The pilot had in excess of 2000 hours of flight time, and had flown aircraft previously in the military.