CEN15FA232

The pilot's failure to maintain control during takeoff due to his impairment from marijuana. Contributing to the accident was the pilot’s impaired decision to fly after using a disqualifying drug.

The private pilot was departing on a local flight with three passengers in the complex, high-performance airplane. Shortly after takeoff, the airplane descended and impacted terrain near a store parking lot. Postaccident examination of the airplane did not reveal any anomalies that would have precluded normal operation. Toxicological testing of the pilot revealed the presence of marijuana and its metabolite (THC and THC-COOH). THC is a psychoactive drug with potential effects such as decreased ability to concentrate and maintain attention, and impaired hand-eye coordination; these effects can present with blood levels of THC as low as 1 ng/ml. Due to postmortem redistribution, the exact level of THC and THC-COOH at the time of the accident could not be determined; however, the pilot's minimum THC level was likely about 5-11 ng/ml, and his THC-COOH level was likely about 3-4 ng/ml. His actual levels could have been higher at the time of the accident, and would likely have been higher during the time of preflight decision-making. The accident was consistent with a loss of control after takeoff due to the pilot's impairment by the effects of marijuana.

A video from that store parking lot camera was reviewed at the store. The video showed the airplane descending in a nose down attitude and that a flame, consistent with a ground fire, started at 1231. 1T7, located about 26 miles north of San Antonio, Texas, was a non-towered airport, which was privately owned and operated by the Kestrel Airpark Runway Association. The airport is a public use airport. Its field elevation was 1,261 feet above mean sea level. The airport listed 122.975 megahertz as its common traffic advisory frequency. The airport is serviced by one runway: runway 12/30. The runway is listed as a 3,000-foot by 40-foot asphalt runway. The runway has an operational restriction listed, which indicated that runway 30 rises rapidly at its north end. The Comal County Coroner was asked to arrange for an autopsy to be completed on the pilot to include taking samples for toxicological testing. The autopsy, conducted by Central Texas Autopsy, PLLC, indicated the pilot's cause of death was multiple blunt force injuries. The FAA Civil Aerospace Medical Institute prepared a Final Forensic Toxicology Accident Report on the toxicological samples taken during the autopsy. The report, in part, indicated: 0.0143 (ug/ml, ug/g) Tetrahydrocannabinol (Marihuana) detected in Blood 0.013 (ug/ml, ug/g) Tetrahydrocannabinol (Marihuana) detected in Lung 0.0037 (ug/ml, ug/g) Tetrahydrocannabinol (Marihuana) detected in Brain 0.1946 (ug/ml, ug/g) Tetrahydrocannabinol Carboxylic Acid (Marihuana) detected in Lung 0.0179 (ug/ml, ug/g) Tetrahydrocannabinol Carboxylic Acid (Marihuana) detected in Brain 0.0119 (ug/ml, ug/g) Tetrahydrocannabinol Carboxylic Acid (Marihuana) detected in Blood The National Transportation Safety Board Chief Medical Officer reviewed the CAMI findings, FAA documents, and the pilot's autopsy and produced a Medical Factual Report. The report indicated that according to these reviewed items, the pilot initially applied for an aviation medical certificate in 2006. Because he marked "yes" to question 18.w regarding non-traffic convictions for misdemeanors or felonies, the aviation medical examiner deferred the pilot's certificate. The FAA requested additional information, which the pilot provided regarding a conviction for driving with a suspended license; once this had been received and reviewed, the FAA awarded the pilot his medical certificate. On the pilot's last application for a medical certificate, he reported no medications or chronic medical conditions. He was issued a first class medical certificate without limitations. This certificate would have been no longer valid for any class on March 31, 2015, six weeks before the accident. The autopsy indicated the cause of death was multiple blunt force injuries due to light plane crash and the manner of death was accident. There was significant damage to the body including multiple lacerations of the heart. No significant natural disease was identified. In addition to CAMI's testing, toxicology testing performed by NMS Laboratories at the request of the forensic pathologist identified 0.034 ug/ml of tetrahydrocannabinol (delta-9 THC, the active component of marijuana) and 0.0084 ug/ml of tetrahydrocannabinol carboxylic acid (THC-COOH, the primary metabolite of THC) in the pilot's cardiac blood specimen. Toxicology testing performed by CAMI identified 0.0143 ug/ml of tetrahydrocannabinol (delta-9 THC, the active component of marijuana) and 0.0119 ug/ml of tetrahydrocannabinol carboxylic acid (THC-COOH, the primary metabolite of THC) in the specimen of cardiac blood sent to them. In addition, THC was identified in the pilot's lung (0.013 ug/ml) and brain (0.0037 ug/ml). Finally, THC-COOH was also found in lung (0.1946 ug/ml) and brain (0.0179 ug/ml). According to details in the CAMI description of Marijuana and in a National Highway Traffic Safety Administration technical report titled Drugs and Human Performance Fact Sheets, THC is described as a psychoactive drug with therapeutic levels as low as 0.001ug/ml. THC has mood-altering effects including euphoria, relaxed inhibitions, disorientation, image distortion, and psychosis. Significant performance impairments are usually observed for at least one to two hours following marijuana use, and residual effects have been reported up to 24 hours. Tetrahydrocannabinol concentrations typically peak during the act of smoking, while peak tetrahydrocannabinol carboxylic acid concentrations occur approximately 9-23 minutes after the start of smoking. Concentrations of both analytes decline rapidly and are often < 0.005 ug/mL at 3 hours. Significant tetrahydrocannabinol concentrations (0.007 to 0.018 ug/mL) are noted following even a single puff or hit of a marijuana cigarette. Chronic users can have mean plasma levels of tetrahydrocannabinol carboxylic acid of 0.045 ug/ml 12 hours after use; corresponding tetrahydrocannabinol levels are, however, less than 0.001 ug/ml. Interpreting post mortem blood and tissue results for marijuana is complex for several reasons. The drug is lipophilic and gets stored in fatty tissues; it may leech back into blood from liver, lung, and brain after death. According to a Journal of Analytical Toxicology article titled Cannabinoids in Postmortem Toxicology, post mortem redistribution may double or triple peripheral levels. A postaccident on-scene investigation was conducted. All major components of the airplane were accounted for at the accident site. The airplane came to rest on terrain and on top of a retaining wall adjacent to a store parking lot about 1/4 mile and 22 degrees magnetic from the intersection of US Highway 281 North and Flightline Drive. The airplane's left wing separated from its fuselage and it was found resting on the retaining wall. The left wing exhibited an outboard skin section that was not painted. This section was consistent with a wing skin replacement. The unpainted section was intact and it remained attached to its wing. Wing separation surfaces exhibited features consistent with overload. The airplane's fuselage and empennage was found resting on terrain at the top of the retaining wall. The cockpit was deformed, discolored, and sections consumed consistent with a ground fire. The right wing was also deformed, discolored, and an inboard section of it was consumed by fire. The empennage was deformed forward into the fuselage in an accordion like fashion. An outboard section of the left horizontal stabilizer was deformed and discolored. The nylock nuts that held the horizontal stabilizer were in-place and could be removed by fingertip pressure. Flight control cables were traced from the cockpit to each control surface. All observed separations in the flight control system were consistent with overload. The flaps and landing gear were found in their retracted positions. The engine and propeller were found forward of the fuselage near the base of a tree that was discolored consistent with a coating of soot. One propeller blade was separated near its hub and the other propeller blade's tip was separated. The separated tip exhibited chordwise gouges on its flat face. Charred pieces of paper were found nearby that contained notes consistent with flight training for an instrument rating. The engine was intact and displayed no signs of catastrophic failure. The engine's accessory case was discolored and deformed. The right magneto and the aft section of the engine driven fuel pump were not in place on the accessory case. The top spark plugs and accessory case were removed. The engine's crankshaft was rotated by hand. Crankshaft continuity was confirmed from the propeller flange to each of the cylinders and to the accessory drive gears. A compression check was performed and all cylinders exhibited suction and a thumb compression. The left magneto exhibited thermal deformation and discoloration. The fuel manifold was intact and its disassembly revealed a trapped liquid