On April 28, 2004, about 1630 eastern daylight time, an amateur built RV-6A, N999SB, was substantially damaged while executing a precautionary landing after departing from the Shannon Airport (EZF), Fredericksburg, Virginia. The certificated private pilot was not injured. Visual meteorological conditions prevailed and no flight plan had been filed for the personal flight conducted under 14 CFR 91. According to the pilot, shortly after takeoff, he was notified that the airplane's tow bar was attached and hanging from the nose wheel. The pilot remained in the traffic pattern and attempted to land on runway 6, a 2,910-foot-long, 100-foot-wide, asphalt runway. Upon turning final, he extended the flaps to 40 degrees, and subsequently the airplane got too slow and could not make the runway. The pilot decided to land on a dirt field, west of runway 6. While touching down, the tow bar came in contact with the ground, and caused the airplane to nose over. Examination of the airplane by a Federal Aviation Administration inspector revealed damage to the landing gear, fuselage skin and nose cowl. The pilot stated that he did not experience any mechanical problems with the airplane. The pilot reported 1,125 hours of total flight experience, which included about 70 hours in the same make and model of the accident airplane. Winds reported at Shannon, at 1620 hours, were from 300 degrees at 5 knots.