On September 7, 2002, at 1430 eastern daylight time, a Piper PA-30-30, N7817Y, registered to a private owner and operated by the commercial pilot, collided with a runway sign during landing on runway 05, at the Winder-Barrow airport in Winder, Georgia. The personal flight was operated under the provisions of Title 14 CFR Part 91, and visual flight rules. Visual meteorological conditions prevailed and no flight plan was filed for the local flight. The pilot and two passengers were not injured and the airplane sustained substantial damage. The flight departed Lawrenceville, Georgia, at 1330 on September 7, 2002. According to the pilot, after flaring to land, the airplane bounced and made a turn to the left at which point he could no longer control it. According to witnesses at the accident site, the airplane porpoised two to three times during the approach to land. After landing, the airplane departed the runway surface at a 45-degree angle and struck a runway sign with the right wing. The left main landing gear collapsed as the airplane spun around. The airplane proceeded tail first across a taxiway and into an open field coming to rest about 1000 feet from the point where the airplane departed the runway. The airplane sustained damage to the right wing, right aileron, left wing, left landing gear and both flaps. The pilot did not report a mechanical problem with the airplane.