History of Flight
The accident occurred on August 8, 2009, at about 0741 eastern daylight time. The experimental amateur-built Kociemba T-Bird II, registration N90458, departed Keymar Airpark (MD42) in Keymar, Maryland, for a local personal flight under visual meteorological conditions. Witnesses observed the airplane disappear behind a line of trees after takeoff, then reappear traveling in the opposite direction. One witness demonstrated that the aircraft banked at a high angle and then nose-dived toward the ground with some rotation. Two witnesses at the airport did not see the airplane but heard its engine; one described the sound as "overloaded and struggling," and the other heard the engine suddenly stop followed by a loud bang.
Aircraft and Pilot Information
The two-seat, high-wing, fixed-gear kit-built airplane was designed by Golden Circle Air and built by the pilot. It was powered by a rear-mounted Rotax 582UL DCDI, 65-horsepower engine with a two-bladed Warp Drive propeller. The pilot, aged 61, held a private pilot certificate issued July 25, 2003, with a single-engine land rating. His most recent FAA third-class medical certificate was issued June 3, 2003, and he reported 78 total flight hours. A logbook review indicated 85.5 total hours as of September 15, 2003, with 7 hours in the accident make and model. A separate ultralight log showed a total time of 98.9 hours as of July 2, 2009, but an entry from April 13, 2008 noted a Hobbs meter error.
Wreckage and Impact Information
The airplane came to rest in a nose-down attitude approximately 4,200 feet southwest of the departure airport. The wooden propeller had little damage and lacked chordwise scratches. Structural tubing in the forward cabin was fractured, with severe corrosion near the fractures. Rudder control cables had an extra 6-inch cable attached to the aft end. The fuel tank was about 7/8 full, and fuel was present throughout the system. Contaminants, including water and particulate, were found in the inline fuel filter, fuel line, and forward carburetor. The fuel pickup fitting had no screen. Engine examination revealed water and particles in the carburetor bowl, and the aft cylinder appeared dry from lack of fuel.
Medical and Pathological Information
An autopsy performed on August 9, 2009 determined the cause of death as multiple injuries. Toxicology testing detected diphenhydramine and zolpidem in the pilot's blood and urine. The pilot's 2003 medical application noted seasonal allergies and the use of desloratadine.
Additional Information
FAA Special Airworthiness Information Bulletin CE-07-06 warns against using automobile gasoline containing alcohol in aircraft, citing risks of vapor lock, corrosion, and phase separation. Rotax Service Instruction SI-2ST-008 allows E10 (up to 10% ethanol) in 582UL engines but urges airframe compatibility checks. The pilot purchased replacement aileron and elevator cables in January 2009, but no corresponding maintenance records were found. On July 1, 2009, the pilot had aborted a takeoff, damaging a jury strut; a replacement was purchased, but no maintenance entry was recorded.