HISTORY OF FLIGHT On July 10, 1995, approximately 1600 central daylight time, a homebuilt Pulsar XP airplane, N912XP, registered to and operated by a private owner, was destroyed when it impacted terrain during descent near Spring Branch, Texas. The private pilot and his pilot rated passenger received fatal injuries. The airplane departed Bulverde Airpark near Spring Branch about 15 minutes before the accident for the local personal flight conducted under Title 14 CFR Part 91. Visual meteorological conditions prevailed and no flight plan was filed. According to a witness, the passenger completed a tour of the shop in San Antonio, Texas, where the Pulsar kit is manufactured and expressed a desire to see a completed airplane. The witness, who was an employee of the kit manufacturer, offered to show the passenger the airplane which was kept in the same hangar as his personal airplane. When they arrived at the Bulverde Airpark, the pilot was "working in the general area of the nose wheel on the plane." The passenger introduced himself to the pilot and "asked general questions about the plane." The witness observed the pilot place 5 gallons of automotive gasoline into the Pulsar's right wing tank. The pilot then invited the passenger "to go on a short flight" and assisted him in "strapping" into the right seat of the Pulsar. The witness pulled his Star-Lite airplane out of the hangar and both airplanes taxied out and took off. The two aircraft climbed to "2,300 to 2,500 feet indicated" and proceeded north. After approximately 8 minutes, the Star-Lite's pilot turned back to the airport and lost sight of the Pulsar. A witness who resides in Spring Branch was in her front yard when she heard a noise like "a loud truck shifting gears." During a telephone interview, conducted by the investigator-in-charge, the witness further described the noise as a "starting and stopping sound." The witness initially observed the airplane "flying pretty high" and then reported "it nose dived straight down, rotating as it went." Another witness "saw the plane flying" and "then the motor was not running." She observed the airplane "coming down at an angle like he was trying to land" and "trying to start his engine." During a telephone interview, conducted by the investigator-in- charge, the witness stated that as she watched the airplane descend, she heard a "grinding" noise alternating with periods of "quiet." She looked away from the airplane and then heard "a big boom." PERSONNEL INFORMATION A copy of the pilot's flight logbook was provided to the investigator-in-charge by a family member. Review of the logbook revealed that the pilot received the majority of the flight training leading to the issuance of his private pilot certificate in the accident airplane. Between October 24, 1990, and June 2, 1994, he logged 60 hours of flight time, 58 of which were in the accident airplane. The pilot received his private certificate on June 3, 1994. There were no further entries in the logbook; however, associates of the pilot indicated he continued to fly the airplane and "may have logged hours elsewhere." AIRCRAFT INFORMATION An experimental airworthiness certificate was issued for the airplane on August 31, 1990. A review of the airframe and engine logbooks by the FAA inspector did not reveal any uncorrected maintenance discrepancies. The most recent logbook entry was dated February 27, 1995, and indicated an airframe total time of 549 hours. The experimental airworthiness certificate indicated that the pilot, Richard H. Meyer, was the builder of the airplane. FAA records showed that, at the time of the accident, the airplane's registered owner was Richard H. Meyer. A copy of a document titled, "Contract for Purchase of Pulsar XP N912XP," dated January 12, 1994, was provided to the investigator-in-charge by a relative of the pilot. The document stated that Pulsar Aviation, Inc., "agrees to purchase" N912XP from "its owner, Mr. Rick Meyer" subject to certain listed conditions. WRECKAGE AND IMPACT INFORMATION On July 11, 1995, a Federal Aviation Administration (FAA) inspector and a representative from the kit manufacturer conducted an on-scene examination and reported the following information. All components of the airplane were located within a circular area approximately 60 to 80 feet in diameter. There were impressions in the ground corresponding to the leading edges of the wings. The engine was buried about 24 inches in the ground and the wooden propeller was shattered. Control continuity was established for the rudder, ailerons, and flaps. Elevator control continuity was established with the exception of a fracture separation of the bellcrank. It was the opinion of the FAA inspector and the kit manufacturer's representative that this fracture was "caused by the impact." The fuel selector was found in the "OFF" position. The wing fuel tanks were compromised; there was evidence of fuel spillage from the right wing tank and no evidence of spillage from the left wing tank. MEDICAL AND PATHOLOGICAL INFORMATION Local law enforcement personnel reported that when they arrived on-scene the pilot's right hand was positioned on the single control stick. An autopsy of the pilot was performed by Roberto J. Bayardo, M.D., Chief Medical Examiner of Travis County at Austin, Texas. Toxicological findings were positive for valproic acid (Depakote). Tests showed that the pilot's blood contained 5.700 ug/mL valproic acid and valproic acid was detected in his liver fluid. Valproic acid is an anticonvulsant prescribed for the treatment of seizures. It is on the Federal Aviation Administration's prohibited usage list for pilots. The manufacturer warns that this medication "may cause drowsiness; patients should observe caution while driving or performing other tasks requiring alertness, coordination or physical dexterity." A family member authorized release of a copy of the pilot's medical records to the investigator-in-charge. These records indicated the pilot was first seen for symptoms of seizures on August 11, 1994. Under Title 14 CFR Part 67, epilepsy is one of the deniable conditions for issuance of an FAA airman medical certificate. The pilot's airman medical certificate was issued on August 12, 1993. According to Dr. Canfield, CAMI Toxicology Laboratory, the level of valproic acid detected was "below therapeutic level, and may not have been high enough to control seizures." TESTS AND RESEARCH On July 25, 1995, a teardown of the engine, a Rotax 912, S/N 3792526, was conducted by an FAA inspector and a representative from the engine manufacturer. The teardown revealed evidence of water pump impeller blade rub on the water pump housing and propeller reduction gear rub on the gear case. No evidence of pre-impact mechanical failure or malfunction was observed. ADDITIONAL INFORMATION The wreckage was released to the estate of the registered owner.