While attempting to take off from a 2,100-ft-long turf runway the pilot observed an abnormal airspeed indication and aborted the takeoff. The airplane then overran the runway, impacted a fence post with the left main landing gear, and nosed over resulting in substantial damage to the right wing and vertical stabilizer. After the accident, the pilot suspected that the pitot tube butterfly cover may have become stuck resulting in the erroneous airspeed indication. Postaccident examination of the airplane’s pitot tube butterfly cover by an FAA inspector revealed no evidence of any preaccident mechanical malfunctions or failures that would have precluded normal operation. Had the pilot aborted the takeoff sooner, or continued the takeoff despite the airspeed indication anomaly, it is likely that the accident could have been prevented.