On September 22, 2023, about 1446 Pacific daylight time, an unregistered experimental, amateur-built Golden Circle T-Bird II was substantially damaged when it was involved in an accident near Arlington, Washington. The noncertificated pilot was fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. According to a witness who was standing in front of a hangar at Arlington Municipal Airport (AWO), he observed the accident airplane complete a series of what appeared to be practice takeoff maneuvers on the west side of the airport during which the airplane would become momentarily airborne. During the airplane’s final takeoff maneuver, it lifted off the ground toward the south and turned right. The airplane narrowly missed impacting trees before it disappeared behind hangars and trees on a northwesterly heading. The airplane reappeared, and the witness stated that it “looked like it was going to dive towards the runway” before the left wing separated in flight. Video of the accident flight taken from the east side of the airport showed the airplane appear above a group of trees on an easterly heading, approaching from the west side of the airport. The airplane turned toward the south and yawed rapidly before it turned to the southeast. Approximately 20 seconds later, the airplane then turned to an easterly heading and exhibited erratic changes in pitch and yaw. The airplane then turned right toward the northeast, crossed over runway 16/34, and continued to turn right at a steep bank angle, at which time it entered a nose-low attitude. Two seconds later, the left wing separated from the airplane; the airplane then entered a rapid descent. The engine’s sound was erratic throughout the video and ceased about 3 seconds after the left wing separated and the airplane started its rapid descent toward the ground. Pilot Information The pilot did not possess an FAA medical certificate, nor did he hold a valid FAA pilot certificate. Logbooks were not recovered to account for his total flight experience. Wreckage and Impact Information The airplane came to rest inverted in a grass area about 275 ft west of the approach end of runway 16. Several structural tubes were located between the main wreckage and separated left wing, which came to rest about 400 ft northeast of the main wreckage. Propeller blade fragments were located around the left wing. The right wing fabric was torn and each of the wing’s structural tubes were bent. The vertical stabilizer was crushed while rudder, horizontal stabilizer, and elevator remained undamaged. The engine remained attached to the fuselage and the propeller blades were attached to the crankshaft through the propeller hub. Figure 1: Wreckage diagram Postaccident examination of the engine did not reveal any preimpact mechanical anomalies that would have precluded normal operation. The ailerons were traced from the cockpit to their flight control surfaces through multiple separations, all consistent with overload failure. According to the airplane installation manual, the wings are secured to the fuselage at the root tube (atop the fuselage structure) via two spars at each wing (forward and aft) and 4 wing struts (forward and aft for the left and right sides). The spars connected to the root tube assembly via bolts, washers, and castellated nuts. The forward and aft wing spars remained attached to the root tube assembly with all the securing hardware in place. The right wing spars exhibited signatures consistent with overload failure at the wing root. The forward left wing spar had been previously repaired and the spar tube was spliced, and a sleeve was installed to couple the separated sections of spar. The sleeve exhibited fracture signatures consistent with overload failure. The aft left wing spar also exhibited fracture signatures consistent with overload. The airplane maintenance records were not located.

Figure 2: Left wing spar with splice and sleeve According to the kit manufacturer, they require customers to purchase replacement parts and would not approve a sleeve as a repair on any structure.

MEDICAL AND PATHOLOGICAL INFORMATION

An autopsy of the pilot was conducted by the Snohomish County Medical Examiner, Snohomish, Washington. The cause of death was “blunt traumatic injuries” and the manner of death was an accident. Postmortem toxicological testing of liver tissue by NMS Labs detected ethanol at 0.95 g/hg, methamphetamine at 16,000 ng/g, and amphetamine at 1500 ng/g; delta-9-tetrahydrocannabinol (delta-9-THC), 11-hydroxy-delta-9-tetrahydrocannabinol (11-hydroxy-delta-9-THC), and carboxy-delta-9-tetrahydrocannabinol (carboxy-delta-9-THC) also were detected. Postmortem toxicological testing by the FAA Forensic Sciences Laboratory detected methamphetamine at 7254 ng/g in liver tissue and at 919 ng/g in muscle tissue, amphetamine at 399 ng/g in liver tissue and at 50 ng/g in muscle tissue, delta-9-THC at 28 ng/g in liver tissue and at 41.8 ng/g in muscle tissue, 11-hydroxy-tetrahydronannabinol (11-hydroxy-THC) 48.5 ng/g in liver tissue and at 3.3 ng/g in muscle tissue, carboxy-delta-9-THC at 30.5 ng/g in liver tissue and at 2 ng/g in muscle tissue, and amitriptyline at 8 ng/g in liver tissue and at 41 ng/g in muscle tissue. Nortriptyline was detected in liver tissue and was detected at 8 ng/g in muscle tissue. Ethanol was not detected in liver tissue or muscle tissue. Blood was not available for testing.

Delta-9-THC is the primary psychoactive chemical in cannabis, including marijuana, hashish, and cannabis edibles. Marijuana is a federal Schedule I controlled substance. 11-hydroxy-THC (more specifically, 11-hydroxy-delta-9-THC) and carboxy-delta-9-THC are metabolites of delta-9-THC. Delta-9-THC may be inhaled or ingested recreationally by users seeking mind-altering effects. It may also be used medicinally, such as to treat illness-associated nausea and appetite loss. Psychoactive effects of delta-9-THC vary depending on the user, dose, and route of administration, and may impair motor coordination, reaction time, decision making, problem solving, and vigilance. The instantaneous level of delta-9-THC in a living person’s blood does not directly predict impairing effects, and interpretation of postmortem tissue levels of delta-9-THC is further complicated by the fact that such levels may differ from antemortem blood levels. Ethanol is the intoxicating alcohol in beer, wine, and liquor, and, if consumed, can impair judgment, psychomotor performance, cognition, and vigilance. Alcohol consumption is not the only possible source of ethanol in postmortem specimens. Ethanol sometimes may be produced by microbes in a person’s body tissues after death. Methamphetamine is a central nervous system stimulant drug. Amphetamine is a metabolite of methamphetamine and is also a central nervous system stimulant. Both methamphetamine and amphetamine are available as federal Schedule II controlled substance prescription medications used to treat attention deficit hyperactivity disorder, narcolepsy, and occasionally obesity. As medicines, the drugs typically carry warnings that they may impair the ability to engage in potentially hazardous activities. In addition to being used medicinally, methamphetamine and amphetamine are frequently produced illicitly and abused recreationally by ingestion, snorting, smoking, rectal insertion, or injection. Seeking an intense euphoric effect, people who abuse methamphetamine and amphetamine typically use higher doses than are used medicinally. Amitriptyline is a tricyclic antidepressant medication that can be used to treat nerve pain, depression, and a variety of other conditions. Nortriptyline is an active metabolite of amitriptyline and is also a prescription medication with similar uses as amitriptyline. Amitriptyline and nortriptyline often carry warnings that they may impair mental and/or physical abilities required for performance of hazardous tasks, such as operating machinery or motor vehicles.