Introduction
On an unspecified date, a pilot contacted the UNICOM frequency at Charleston Executive Airport (JZI) in Charleston, South Carolina, requesting an airport advisory. An airport employee reported winds from 180 at 12 knots gusting to 17. The pilot initially stated he would land on runway 18, but was informed no such runway existed. He then said he would land on runway 27, then runway 22. The employee stepped outside to observe.
Sequence of Events
The airplane was observed southwest of the airport moving northeast perpendicular to runway 22 at about 500 feet altitude. It was on a left base for runway 22 but overshot the runway. The airplane then initiated a "tight, low right turn" away from the airport. Shortly thereafter, the airplane stalled and completed two revolutions before disappearing from sight.
Findings
Examination of the airframe, flight controls, engine assemblies, and accessories revealed no pre-crash mechanical failure or malfunction. A forensic toxicology test on pilot specimens by the FAA Bioaeronautical Sciences Research Laboratory found Tramadol (also known by trade name Ultram) in the pilot's blood at a level at least twice that of maximal regular doses. Single doses of Tramadol have been shown to cause mild impairment of psychomotor abilities. Diphenhydramine was also found in the pilot's blood.
Probable Cause
The official probable cause is the pilot's failure to maintain airspeed during a turn from base to final, resulting in an inadvertent stall/spin. Contributing to the accident was the impairment of the pilot due to the combination of drugs found in his toxicological report.
Conclusion
The accident investigation concluded that the stall/spin was precipitated by the pilot's loss of airspeed, and his impairment from Tramadol and Diphenhydramine was a contributing factor.