On October 28, 2001 about 1827 eastern standard time, a Beech C23, N24697, registered to a private individual, started to takeoff from a taxiway and lost control in the grass at the Athens Airport, Athens, Georgia. Visual meteorological conditions prevailed at the time and no flight plan was filed for the 14 CFR Part 91 personal flight. The airplane was substantially damaged. The private pilot and the passenger reported serious injuries. The flight was originating at the time, and was en route to Dawson, Georgia. According to the pilot, after landing, he taxied to the fixed-base operator, and he shut down the engine. This was his first time at this airport; he landed during daylight and taxied for takeoff during darkness, about 40 minutes later. After restarting the engine, he made radio contact with ground control, and was directed to taxi to runway 27. He said he missed the turn to taxiway B-3, was then directed to taxiway A-4 and held short of runway 27. After completing the run-up, and checklist, he contacted ground control. He said, ".….it was so dark I moved over so that the taxi lights were right on top of the yellow centerline. I looked ahead into total darkness for the runway." He said he had to looked down to continue on the taxi centerline, then up to search for the runway, then down to taxi centerline. As he continued to search for the runway, air traffic control (ATC) shouted, "Stop…..Stop." He applied the brakes, went over the 40-foot drop off, impacting nose first, and nosed over coming to rest upside down. According to the FAA inspector's memorandum, the pilot-in-command (PIC) was cleared to the hold short of runway 27, prior to getting clearance for takeoff. After getting clearance for takeoff, the PIC turned to the right placing him on a parallel taxiway that leads to runway 27. He ".….immediately went to full power," unaware that he was on the taxiway and not on runway 27. He needed to have gone another 25 to 30 yards before turning right onto runway 27. The tower made several attempts to "stop" the PIC before the airplane crossed the approach end of runway 27. After departing the hard surface the airplane went into a grassy area, down a 40 foot drop off coming to rest inverted. The PIC told the FAA inspector it was his first time at this airport alone and he "admitted to have erred in judgment causing this accident." The pilot received his private pilot rating April 2001. He had a total of 117 hours in all aircraft, and72.6 hours in this make and model airplane, and 8 hours of night operations.