On May 14, 2000, at about 1315 eastern daylight time, a Mclarty Vans RV-4, N45DR, registered to a private owner, operating as a 14 CFR Part 91 personal flight, crashed after takeoff from a private airport. Visual meteorological conditions prevailed and no flight plan was filed. The airplane sustained substantial damage. The commercial pilot and one passenger were transported to a local hospital, and died during treatment. The flight was originating from Apex, North Carolina, at the time of the accident. The brother of the deceased pilot stated his brother conducted and engine run-up and magneto check. The engine sounded a little rough but smoothed out. The airplane was observed on the takeoff roll, became airborne and started a shallow left turn over the trees. He heard a sound like the engine backfired, observed black smoke, and watched the airplane until it disappeared from view behind the trees. He ran to the crash site and saw the airplane adjacent to road. The airplane had collided with trees and was located on the opposite side of a ditch. A witness stated he was in his house looking out his window when he saw a blue and white airplane. The airplane was in a 45-degree nose-high attitude over the trees, and he did not hear any engine noise. It did not appear as if the pilot had control of the airplane. It came down like a tree that was falling. The airplane hit the ground wings level with the fuselage intact and slid about 10 feet, missing a tree head on before it came to a complete stop in his front yard. He ran to the airplane to assist. He observed two victims that had sustained serious injuries and immediately called 911 to report the accident. Examination of the airframe, flight controls and engine assembly revealed no evidence of a precrash mechanical failure or malfunction. (For additional information see FAA Inspector Statement and Textron Lycoming Aircraft Mishap Investigation Single Engine Final Report attachments to this report.) The servo fuel injector, flow divider, fuel nozzles, LASAR spark advance regulator, M4001 ignition harness, and the left and right magnetos were retained for further analysis. Examination of the fuel injector, flow divider and fuel nozzles were examined at an authorized repair station. A functional test revealed no deficiencies. Examination of the left and right magneto, ignition harness, and LASAR controller was conducted by Unison Industries in the presence of the FAA. No anomalies were detected in any of the subject components and the system functioned normally when tested. Although one of the ignition leads missed sporadically, the miss was due to the impact damage suffered by the harness and not due to any defects in the component. (For additional information see Unison Industries Report an attachment to this report.) Dr. George H. Clarke, Office of the Chief Medical Examiner, Chapel Hill, North Carolina, conducted postmortem examination of the pilot on May 15, 2000. The cause of death was multiple traumatic injuries. The Forensic Toxicology Research section, Federal Aviation Administration, Oklahoma City, Oklahoma, performed postmortem toxicology of specimens from the pilot. The studies were negative for carbon monoxide, cyanide, and ethanol, basic or acidic drugs. Dr. Dana Copeland, Medical Examiner, Chapel Hill, North Carolina conducted postmortem examination of the passenger, on May 15, 2000. The cause of death was multiple traumatic injuries. The Office of the Chief Medical Examiner, Chapel Hill, North Carolina, performed postmortem toxicology of specimens from the passenger. The studies were negative for ethanol. The wreckage of N45DR was released to Mr. Harry Brooks, Carson Brooks Inc., on May 15, 2000. The aircraft logbooks were released to Mr. Brooks on June 12, 2000. The components retained for further analysis were released to Mr. Brooks on July 7, 2000.