ERA11FA431

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.

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.

HISTORY OF FLIGHT On July 31, 2011, about 1319 eastern daylight time, a Beech G35, N156RP, experienced an in-flight break up during a descent over Byron, Georgia. The private pilot was fatally injured. The airplane came to rest in a vacant lot in a residential subdivision and was substantially damaged when it impacted terrain. The airplane was registered to and operated by a private individual under the provisions of 14 Code of Federal Regulations Part 91 as a personal flight. Visual meteorological conditions prevailed and no flight plan was filed. The flight originated from Stuart Powell Field Airport (DVK), Danville, Kentucky at approximately 1119; destined for Perry-Houston County Airport (PXE), Perry, Georgia. According to information obtained from the Federal Aviation Administration (FAA), the pilot was in cruise flight at 9,200 feet when he cancelled visual flight rules flight following with the Atlanta Air Route Traffic Control Center. Radar data tracked 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 approximately 3,000 feet, the ground speed was reduced to 178 knots before radar contact was lost with the airplane. No radio transmissions were received from the pilot after radar contact was lost. Witnesses reported that they were working in a field when they heard a loud "popping" sound. They looked up and saw an airplane and what looked like a wing separating from it. The airplane began to spin before crashing into the ground. One witness called 911 and went over to the crash site to see if he could help. PERSONNEL INFORMATION The pilot, age 44, held a private pilot certificate with ratings for airplane single-engine land. He also held a third-class airman medical certificate issued on March 31, 2010, with no limitations or waivers. The pilot's logbook was not recovered for review. A review of the pilot's application for insurance revealed that in January 6, 2011, he reported on an updated application that he had 400 total hours and 140 hours in make and model. AIRCRAFT INFORMATION The three-seat, low-wing, retractable-gear airplane, serial number D-4492, was manufactured in 1956. It was equipped with a Continental E-225-8, 225 horsepower engine, which was equipped with a Hartzell two-blade propeller. A review of the aircraft logbooks indicated that on October 1, 1995, the original logbooks were lost and the previous owner at the time estimated the aircraft to have 4,000 hours. A review of maintenance logbook records revealed that the last annual inspection was completed on June 4, 2011 at a tachometer time of 366.18. The airframe total time was 4,172.2 at the time of the annual inspection. The airplane’s tachometer was damaged during the accident. Further review revealed that on July 2, 1996 the left and right elevators were re-skinned. The Airworthiness Directive (AD 94-20-04) was documented as paragraph 3 note 2-3 of AD by Supplemental Type Certificate Kit No. 35-4016-3 was verified. 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. "VNE = 202 MPH (175kph) Yellow 175 MPH (152 kph) to 202 MPH." During the postaccident examination of the airspeed indicator, the indicator needle was stuck at the 192 MPH position. METEOROLOGICAL INFORMATION The reported weather at PXE, which was located about 8 miles south of the accident site, at an elevation 418 feet, was: wind 290 degrees at 7 knots, visibility 10 statute miles; clear skies; temperature 33 degrees Celsius (C); dew point 22 degrees C; altimeter 30.02 inches of mercury. WRECKAGE AND IMPACT INFORMATION The airplane was examined at the accident site on July 31 and August 1, 2011. The accident site was located in a vacant lot in a residential subdivision. The wreckage debris was spread throughout the subdivision on a path approximately 970 feet long. The wreckage debris path was on a magnetic heading of 230 degrees. The cockpit cabin was crushed and breached, and left wing remained attached at the wing root and carry through spar. The entire right wing was separated at the wing root and was located approximately 500 yards from the main wreckage site, and was also on a 230 degree heading. Diagonal wrinkles were present along the upper and lower wing skins. Pulled rivets were present on the leading edge at the lap joint outboard of the stall vane. The left wingtip separated, and was located in the vicinity of the main wreckage. The left aileron separated at the inboard edge of the outboard hinge. The left flap remained attached. The left flap actuator measured 1.75 inches, corresponding to a flaps retracted position. The left main landing gear was folded in the gear well. Residual fuel remained in the left main and aux tanks. The right wing separated from the wing carry-through structure inboard of the attach fitting. The forward spar carry-through was fractured. The upper portion of the forward spar carry-through separated in the vicinity of rivets in the wing attach fitting. The nested C-channels in the lower portion of the spar carry-through was separated, with small portions of aluminum deformed upward approximately 90° in the bottom of both C-channels. The forward portion of the forward spar web was bent forward and downward. The right landing gear push rod was bent downward and aft. The inboard rib of the right wing was damaged where the right landing gear push rod had been pulled downward through the lightening hole. The aft upper wing attach fitting was fractured on the inboard side at the furthest outboard line of rivets. All associated structures were separated. The aft lower wing attach fitting remained intact with associated structure that remained attached, bent downward and aft. The right main landing gear remained attached and folded in the gear well. The right flap remained attached. The right aileron cables separated at the bell crank and pulled through the wing. The left stabilizer separated from the aft fuselage, but remained attached by the elevator trim cables. The trim cables tore through the bottom surface of the left stabilizer to the area of the inspection plate. The trim cables tore down through the aft fuselage structure approximately 1 inch. Wrinkles were present on both the upper and lower portions of the stabilizer. The left stabilizer skin was deformed laterally along the aft stabilizer spar. Fractures were present on the forward and aft stabilizer spars. The left ruddervator separated from the left stabilizer and separated into four pieces and revealed buckling throughout the span of the stabilizer. The left ruddervator horn separated from the hinge and the left ruddervator push rod. The ruddervator horn was located at the beginning of the wreckage path. The right stabilizer separated from the aft fuselage. The trim cables tore through the bottom surface of the right stabilizer to the inspection plate. The trim cables tore through the aft fuselage skin approximately 6 inches. The forward spar of the right stabilizer exhibited a small portion of the bottom of the C-channel bent downward. The right elevator remained attached. The right elevator counterweight separated from the elevator. The right ruddervator horn separated from the hinge and the right ruddervator push rod. The right ruddervator push rod also separated from the differential mechanism. Buckling was observed throughout the span of the stabilizer. The right ruddervator horn was located on side of a home and had impacted a roof at the beginning of the wreckage path. The fuselage was resting on its right side with compression toward the left side of the fuselage. The upper aft fuselage structure separated from the fuselage. Rudder and elevator control continuity was confirmed from the differential mechanism to the aft spar.