On July 10, 1995, a Meyer PULSAR XP (registration N912XP) was involved in an aviation accident near Spring Branch, TX. Investigators recorded the probable cause as: The pilot's improper positioning of the fuel tank selector and his failure to maintain airspeed. A factor was the pilot's diverted attention to the power loss. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
Two witnesses reported hearing a grinding sound from the engine before the airplane nose-dived vertically. The fuel selector was off, and no pre-impact mechanical anomalies were found. Toxicology tests detected valproic acid, an anticonvulsant not approved for flying, in the pilot's system at a sub-therapeutic level.
Accident Overview
A single-engine airplane crashed under near-vertical impact, with wreckage confined to a circular area approximately 70 feet in diameter. All major components were located within that area.
Witness Reports
Two witnesses reported hearing the engine make a grinding or starting and stopping sound, as if the pilot was trying to start the engine. One witness stated the airplane was flying high and then nosedived straight down, rotating as it descended.
Investigation Findings
Examination of the airframe and engine revealed no evidence of any pre-impact mechanical anomalies. The fuel selector valve was found in the off position. Toxicological testing showed the pilot's blood contained 5.700 ug/mL valproic acid and the substance was also detected in his liver fluid. Valproic acid, known by the brand name Depakote, is an anticonvulsant that can cause drowsiness and is not approved for use while flying. Review of the pilot's medical records indicated he was prescribed Depakote for the treatment of seizures. According to the Civil Aerospace Medical Institute (CAMI), the drug concentration was below therapeutic level and may not have been high enough to control seizures.