Accident Summary
On August 8, 2009, at 1015 central daylight time, an experimental, amateur-built Bradley Stump Kolb M3X (serial number M3X6-4-0084, registration N2456) was substantially damaged following a loss of control in-flight and ground impact in Calhoun, Tennessee. The certificated private pilot, who owned the airplane, and a passenger were killed. Visual meteorological conditions prevailed, and no flight plan was filed for the personal flight under 14 CFR Part 91. The flight originated from Hardwick Field (HDI) in Cleveland, Tennessee, at an undetermined time.
Witness Account
According to a witness who heard the airplane passing by, the airplane climbed straight up and performed a "cartwheel" maneuver, coming straight down before leveling out. The pilot repeated this maneuver twice more. On the third attempt, the airplane went straight up, flipped over backward at approximately 200 feet above the ground, began spinning, then collided with the ground. The witness contacted 911 to report the accident.
Pilot Information
The 53-year-old pilot held a private pilot certificate with airplane single-engine land ratings and a third-class medical certificate issued on October 17, 2007, with no restrictions. His most recent medical certificate indicated 85 hours of flight time. His pilot logbook was not recovered for examination.
Aircraft Information
The two-seat, high-wing, fixed tricycle gear aircraft was manufactured in 2008. It was powered by a Hirth rear-mounted 270-hp engine and equipped with a fixed-pitch composite propeller. The airplane's logbook showed its last conditional inspection on March 25, 2009, with a total time of 27.2 hours. The operating limitations (item 14) prohibited aerobatic flight, defined as intentional maneuvers involving abrupt changes in attitude, abnormal attitude, or abnormal acceleration not necessary for normal flight.
Wreckage Examination
Examination by a Federal Aviation Administration (FAA) inspector revealed that the airplane impacted trees and the ground in a near-vertical nose-down attitude, substantially damaging the engine, cockpit, wings, empennage, and stabilizers. No evidence of preimpact mechanical failure or malfunction was found in the airframe, engine, or system components.
Medical and Toxicological Findings
An autopsy performed on August 10, 2009, by the University of Tennessee Medical Center reported findings of "Multiple blunt force injuries." Forensic toxicology by the FAA Bioaeronautical Sciences Research Laboratory detected Diphenhydramine, Normeperidine, and Promethazine in the liver and spleen, but no ethanol in vitreous. Carbon monoxide and cyanide tests were not performed. The pilot's most recent medical certificate application (October 17, 2007) noted no medications or conditions requiring their use.