Aircraft Accident/Incident Report

Byron, Georgia 31008
Sunday, July 31, 2011 13:19 EDT

During a cross-country flight, about 9,200 feet mean sea level, the pilot cancelled his visual flight rules flight following and descended toward the destination airport. Review of the radar data showed the airplane descending from 9,200 feet at a rate of 2,000 feet per minute and a ground speed of 180 knots. At an altitude of about 3,000 feet, the ground speed was 178 knots and radar contact was lost. No radio transmissions were received from the pilot after radar contact was lost. Witnesses who were working in a field said they heard a loud "popping" sound. They looked up and saw an airplane and what looked like a wing separating from it. They continued to watch the airplane as it began to spin before crashing into the ground. Examination of the airplane revealed that the airplane wings had experienced high positive forces when the stabilizers broke in a downward direction. Once the stabilizers broke, the airplane immediately pitched down and changed rapidly from a high positive angle of attack (AOA) to a high negative AOA. The high negative air loads on the wings caused the right wing to break in a downward direction and caused the left wing and fuselage to rotate left wing down. Further breakup analysis indicated that there was no specific evidence of flutter. A review of the airplane flight manual revealed the never-exceed speed (VNE) for calculated and indicated airspeed was 176 knots. During the postaccident examination of the airspeed indicator, the indicator needle was stuck at the 192 mph position. It is likely that as a result of the continued flight beyond the VNE envelope during a steep descent to the destination airport, the airplane broke up in flight due to the airplane exceeding the design limits.

The pilot’s sustained flight at airspeeds in excess of the airplane's never exceed speed during a steep descent, which resulted in a subsequent in-flight structural failure due to overstress.