Aircraft: Beech G35. Injuries: 1 Fatal. Location: Byron, Ga. Aircraft damage: Destroyed.
What reportedly happened: The private pilot, 44, had logged about 400 hours, including 140 in the Bonanza. The accident happened during a cross-country flight.
When the airplane was at 9,200 feet MSL, the pilot cancelled VFR flight following and initiated a descent toward the destination airport.
Review of the radar data showed the plane descending 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, looked up and saw an airplane and what looked like a wing separating from it. They continued to watch the airplane spin into the ground.
Examination of the wreckage revealed that the 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 to a high negative angle of attack. 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.
There was no specific evidence of flutter.
During the examination of the airspeed indicator dial, it was noted that it was marked per the airplane flight manual with mph on the outside and knots on the inner ring. Never exceed speed (Vne) was marked as 202 mph with the caution range (yellow arc) depicted as 175 mph to 202 mph. The post-accident examination of the airspeed indicator found the indicator needle was stuck at the 192 mph position.
Investigators determined that it was likely that, as a result of the continued flight beyond the never exceed envelope during a steep descent, the airplane broke up in flight due to the exceeding design limits.
Probable cause: 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 over-stress.
NTSB Identification: ERA11FA431
This July 2011 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.