On July 19, 2016, at 1233 eastern daylight time, a Costruzioni Aeronautiche Tecnam P2008, N615BS, was substantially damaged following a rejected takeoff and runway excursion at Warrenton-Fauquier Airport (HWY), Warrenton, Virginia. The private pilot was not injured. The airplane was registered to and operated by the pilot under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Day, visual meteorological conditions prevailed at the time, and no flight plan was filed. The local flight was originating at the time of the accident. The pilot reported that he was on the ramp and ready for departure when he heard via the airplane's radio a helicopter calling "downwind, base, final, and departure." He made a right turn onto the runway and observed a helicopter hovering over the runway, ahead of his position. After initiating the takeoff roll, he elected to reject the takeoff to avoid a possible collision. He had recently transitioned to a new airplane with toe brakes, and his previous airplane was equipped with a hand brake. He pushed hard on the brakes, "very likely too much on the left side" and the airplane departed the left side of the runway. The airplane departed the runway surface and nosed down in the grass. The pilot did not report any mechanical malfunctions or failures with the airplane that would have precluded normal operation. The pilot, age 87, held a private pilot certificate with a rating for airplane single engine land and glider. He also held a FAA experimental aircraft builder certificate. The pilot held a FAA third class medical certificate and reported 1,295 total hours of flying experience on his most recent medical certificate application that was dated October 28, 2013. He reported 7 hours of flying time in the accident airplane make and model.