On June 26, 2003, about 1438 Pacific daylight time, an amateur built, experimental category, Herrin Hornet airplane, N1424, was destroyed after colliding with terrain near the Chehalem Airpark (17S), Newberg, Oregon. The airplane was owned by the pilot, and was being operated as a visual flight rules (VFR) personal/pleasure flight under the provisions of Title 14, CFR Part 91, when the accident occurred. The private pilot, the sole occupant of the airplane, was fatally injured. Visual meteorological conditions prevailed and no flight plan was filed for the local flight. A witness, who is employed at the airport, reported that the pilot of the accident airplane made numerous high-speed taxi runs prior to the accident flight. After completing the taxi maneuvers, the pilot told the witness he was apprehensive about trying to fly the airplane on account of localized gusty winds. After talking to the witness, the pilot taxied back to the runway and resumed the taxi tests. The witness reported that after completing a number of passes down the runway, he observed the airplane takeoff. He reported that the airplane appeared to be porpoising as it ascended over the runway. Additional witnesses reported that they observed the airplane in a climbing right turn over the airport. The airplane climbed to about 200-300 above ground level (AGL) and appeared to be in a modified downwind for runway 25. The witnesses reported that as the pilot turned from right base to final, the airplane abruptly pitched nose down (approximately 60 degrees). The witnesses reported that the airplane momentarily returned to a level flight attitude, but pitched down a second time just before impacting terrain in a nose low attitude. Maintenance records indicated that the airplane was issued a special airworthiness certificate, experimental category, on April 23, 2003. The accident flight was the airplanes first flight subsequent to receiving the airworthiness certificate. An FAA airworthiness inspector from the Portland, Oregon, Flight Standards District Office examined the aircraft following the accident and reported that there was no evidence found to indicate a mechanical failure or malfunction. An autopsy on the pilot was conducted by the Oregon State Medical Examiner's Office, on June 27, 2003. According to the autopsy report, the pilot's cause of death attributed to head and chest injuries. The manner of death was listed as accidental.