ERA15FA335

The pilots' failure to maintain airplane control during a low-altitude maneuver.

The pilots, who co-owned the airplane, departed for a personal flight and, after completing one circuit around the airport traffic pattern, were performing a low-altitude, high-speed pass over the runway. About halfway down the runway length, the airplane entered a barrel roll to the left and, after passing through 180 degrees of roll, began a descent that continued to ground contact. Postaccident examination of the flight controls revealed no evidence of preimpact failure or malfunction. Although the rear seat flight control stick was found separated and had not been properly secured in compliance with a service bulletin, it was damaged in a manner consistent with the impact and likely did not contribute to a loss of control. The pilots' decision to perform aerobatic maneuvers at low altitude significantly diminished their margin for error, and once the airplane began to descend while maneuvering, the pilots likely did not have adequate time to recover before impacting the ground.

Postmortem examinations of the occupants were performed by the Wake Forest Baptist Medical Center, Winston-Salem, North Carolina. Major findings at autopsy for both indicated multiple blunt force injuries. No natural disease was noted of either occupant. Both occupants exhibited fractures of their right ulna and radius. Forensic toxicology was performed on specimens of both occupants by the FAA Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma. The toxicology reports for both occupants indicated testing for carbon monoxide and cyanide was not performed. No volatiles were detected in specimens for either occupant, and no tested drugs were detected in the specimens of the front seat occupant, while unquantified amounts of Irbesartan was detected in the liver specimen, and Rosuvastatin was detected in the liver and muscle specimens of the rear seat occupant. A surface observation weather report taken at Davidson County Airport (EXX), Lexington, North Carolina, at 1355, indicated the wind was calm, the visibility was 10 statute miles, and clear skies existed. The temperature and dew point were 32 and 19 degrees Celsius, respectively, and the altimeter setting was 30.06 inches of mercury. The accident site was located about 10.9 nautical miles and 316 degrees from EXX. The front seat occupant, age 68, held a private pilot certificate with an airplane single engine land rating originally issued March 29, 2015. On the application for that certificate, he listed 78.7 hours of total flight experience; the checkride was performed in a Cessna 150L. There were no records of enforcement actions. He held a Federal Aviation Administration (FAA)-issued third class medical certificate, with a limitation to wear corrective lenses for near and distant vision issued July 8, 2014. The rear seat occupant, age 71, held a commercial pilot certificate with airplane single engine land, airplane multi-engine land, and instrument airplane ratings. A review of his FAA airman records revealed no records of enforcement actions. He held an FAA-issued third class medical certificate with a limitation to wear corrective lenses issued May 1, 2014. On the application for the medical certificate he listed a total civilian flight hours as 2,526. Friends reported he was formerly a pilot for the U.S. Air Force, was an instructor pilot in T-38's, and was familiar with aerobatic flight. The airplane impacted a pond adjacent to the airport. The main portion of wreckage consisted of the fuselage, empennage, and portion of main spar, and was about 206 feet and 214 degrees from the departure end of runway 27. Components of the airplane were located in the pond, on land, and in close proximity to the main wreckage. Debris from the airplane was oriented on a magnetic heading of 320 degrees. A fuel sheen was noted on the water, and trees/bushes adjacent to the pond immediately adjacent to the accident site exhibited browning consistent with fuel spill. All components necessary to sustain flight remained attached or were in close proximity to the accident site. The left wing which exhibited extensive impact damage, the full span was accounted for, and the lower wing skin exhibited fire damage. The flap remained attached at the hinge, but the aileron with attached balance weight separated and was found in close proximity to the wreckage. The aileron bellcrank to aileron pushrod remained connected to the bellcrank attached to the aft side of the main spar; however, the rod end near the aileron control surface exhibited bending overload. The aileron bellcrank to stick pushrod exhibited bending overload about 7 inches outboard from the wing root. Closer examination of the bellcrank attached to the aft side of the main spar revealed the lower portion of the bellcrank adjacent to the aileron bellcrank to stick pushrod was slightly deformed down consistent with contact by the end of the pushrod. The main spar just inboard of the aileron bellcrank was buckled aft. Examination of the right wing revealed it was fragmented in multiple pieces, but the full span including the wingtip was accounted for. The flap and aileron were separated but both were recovered. Examination of the aileron revealed the leading edge was crushed down and aft, and the aileron balance weight was separated but not recovered. The aileron bellcrank to aileron pushrod was bent about midspan and also near the control surface. The pushrod remained connected to the bellcrank on the aft side of the main spar, but was separated from the rod end near the control surface; the threaded portion of the rod end near the aileron control surface was bent and fractured. The aileron bellcrank to stick pushrod remained attached to the bellcrank on the aft side of the main spar but was fractured due to bending overload just outboard of the attach point at the bellcrank and also at the wing root. Distortion of the aileron bellcrank attached to the aft side of the main spar was noted at the attach points for both pushrods. The exterior surface of the aileron bellcrank to aileron pushrod near the bellcrank attach point revealed multiple marks oriented about 50 degrees to the span on the rod adjacent to 2 rivets. One rivet exhibited a flat spot immediately adjacent to the 50-degree marks, while another rivet exhibited a wear/chafing spot. Personnel from the recovery crew reported that the threaded portion of the rod end near the bellcrank attached to the aft side of the main spar fractured while unloading the wreckage from the trailer. The flap was deformed and pulled from hinge. Examination of the empennage revealed all primary and secondary structure and flight control surfaces remained attached. The right horizontal stabilizer was bent up in form of an inverted "V". The elevator pushrod was bent but remained attached at the rear and intermediate bellcranks, but was fractured near the aft control stick attach point due to bending overload. Both rudder control cables remained connected at the rear bellcrank while the left and right rudder control cables were fractured in tension overload 12 feet 4 inches and 10 feet 10 inches, respectively, forward of the rear bellcrank. The remaining sections of the fractured rudder cables remained connected to the respective idler arm in the cockpit. Separate rudder cables remained connected to each idler arm, and were continuous through a guide on the side of each rudder pedal, to their respective attach points on the firewall. The rear seat left rudder pushrod assembly remained attached to the idler arm, but the threaded portion of the rod end was bent near the idler arm. The threaded portion of the rod end for the rear seat right rudder pushrod assembly was bent and fractured at the attach point at the idler arm. The elevator trim tab was in the neutral position with the elevator positioned to neutral. The cockpit was fragmented, and the front and rear seat aileron and elevator flight control assemblies were separated from the aircraft. The left and right aileron rod ends remained attached to their respective attach points on the control column; however, both aileron pushrods were fractured just outboard of the attach point. The elevator rod end remained attached to the rear seat control stick base; however, the threaded portion of the rod end was bent and fractured. The control column and pushrod assembly within the control column were deformed and fractured about midspan. The forward control stick and rear seat control stick base remained attached to the fractured control column; however, the rear seat control stick part number (P/N) WD-812 was separated from the rear control stick base P/N WD-412A. No securing hardware was found. Closer examination of the rear seat control stick base (stick base) revealed a single hole through the wall on the left side. The hole was deformed on the upper portion, which was located about .125 inch below the upper surface of the socket. The