CEN23FA239

The pilot’s loss of control due to spatial disorientation while operating in instrument meteorological conditions. Contributing to the accident was the pilot’s impairment from the prohibited substance; however, the extent of impairment could not be determined.

The instrument-rated pilot was conducting a personal cross-country flight with a passenger. An airport surveillance camera captured the airplane climbing wings level into a 300-ft overcast ceiling shortly after takeoff. Based on a review of recorded flight track data, shortly after the airplane climbed into the clouds it entered a climbing left turn but did not establish a direct course to the intended destination or climb to 3,000 ft mean sea level (msl) as cleared by the air traffic controller before the takeoff. Rather, the airplane flew through the direct course while it climbed and descended before it ultimately entered a steep descending right turn. In the moments before the accident, the airplane exceeded the never exceed airspeed (VNE) as it descended more than 13,500 feet per minute (fpm) while in the steep right turn. A witness reported seeing the airplane descend “nose first” into a grass field and wooded area, which was followed by a large explosion. The airplane fragmented upon impact with terrain and trees, but a wreckage layout confirmed that all major structural components and flight controls were accounted for at the accident site. Flight control continuity could not be confirmed due to extensive impact-related damage; however, the airplane’s recorded flight path established that the airplane turned left and right and both climbed and descended during the flight. Additionally, a sound spectrum analysis of recorded audio concluded that the engine was operating when the airplane impacted terrain. The recorded flight path was consistent with the pilot experiencing spatial disorientation while flying in instrument meteorological conditions (IMC). The pilot’s recent instrument flight experience could not be adequately assessed with the available logbook evidence. FAA Forensic Sciences toxicological testing detected ethanol in both lung and muscle tissue of the pilot. The presence of ethanol in both specimens means that the possibility of alcohol consumption could not be excluded. The negative ethanol result from the autopsy toxicology report adds little information due to the relatively high reporting limit used. However, based on the condition of the pilot’s remains and the difference in ethanol levels between lung and muscle tissues, at least some of the detected ethanol likely was from postmortem production. If the pilot consumed ethanol, the ethanol level in lung tissue was not low enough to exclude some impairing effects, particularly in the presence of other potential central nervous system (CNS) depressant substances. Thus, whether ethanol effects contributed to the crash could not be determined. The pilot’s toxicological results indicated the use of gabapentin. Based on the gabapentin levels measured in tissue, it is likely that the pilot was experiencing some effects from the gabapentin. Specific effects are uncertain; however, it is possible for gabapentin to affect the vestibular system and proprioception, which are important for spatial orientation. Toxicological results also indicated the pilot’s use of codeine. The use of codeine can cause CNS depression as well as increase the risk of gabapentin’s effects on the CNS. The toxicological results also indicated the pilot’s use of delta-8 THC. Delta-8 THC has the potential to alter perception and cause impairment. To what extent the combination of multiple CNS-active substances may have affected, the pilot’s cognitive processing and motor skills is unknown. Thus, based on the available information, it is possible that the pilot was impaired by the use of gabapentin, codeine, and delta-8 THC contributed to the accident. However, notably, the FAA prohibits an individual who uses gabapentin and/or delta-8 THC from acting as pilot-in-command of an aircraft. The pilot reportedly had obstructive sleep apnea (OSA) treated with a continuous positive airway pressure (CPAP) device. Inadequately treated OSA can contribute to increased sleepiness, diminished attention, and cognition leading to an increased risk of performance errors. The pilot’s medical records regarding his use of a CPAP device were insufficient to determine whether he complied with OSA therapy; however, the pilot’s family reported that he was traveling with his CPAP device. Regardless, without additional information on the pilot’s compliance with OSA therapy, whether the effects of his OSA condition contributed to the accident could not be determined.

The accident site was located in between two low-level troughs with the low-level wind flow moving across the area from the Great Lakes region increasing the low-level moisture. In addition, the surface winds were light, creating an environment favorable for the formation of low clouds and fog. The weather station at the departure airport reported a calm wind, visibility of 5 miles, and a 300 ft agl overcast ceiling at the time of the accident. The weather forecast information applicable for the accident time indicated that Airmen's Meteorological Information (AIRMET) Sierra for IFR conditions due to precipitation and mist was valid for the site at the accident time. The Graphical Forecasts for Aviation (GFA) applicable to the accident site and that were valid when the flight departed indicated low instrument flight rules (LIFR) to IFR conditions and a north wind of 5 knots. The GFA cloud forecast indicated broken-to-overcast clouds with bases about 1,000 ft msl and cloud tops about 3,000 ft msl. A review of weather satellite imagery and High-Resolution Rapid Refresh models noted cloud tops around 6,500 ft msl. However, several pilot reports located around the site and within 90 minutes of the accident reported cloud tops between 3,000 ft msl and 3,800 ft msl. A search of archived information established that the pilot filed a flight plan with Leidos Flight Service before the flight departed, but he did not request any weather information from Leidos. Although the pilot had a registered account with ForeFlight, an online service that can provide weather information, there was no recorded activity for his account on June 13-14, 2023. Based on the available information, it is unknown what weather information, if any, the pilot checked or received before or during the flight. A GoPro Hero 8 device was recovered from the wreckage and its contents were reviewed by the NTSB Vehicle Recorder Laboratory. The last file written to the device’s memory card was a photo, shown as figure 4, that captured the airplane’s right wing as seen through the right passenger window. Additionally, the photo showed that there were significant clouds that obstructed the view of the ground and were consistent with IMC. Based on the file metadata, the photo was captured at 0903:01, about 0.35 nm southwest of the accident site, at a GPS altitude of 2,297 ft. Figure 4. GoPro Hero 8 photo captured at 0903:01 The pilot’s flight logbook was recovered at the accident site. The final logbook entry was dated May 15, 2023; based on postaccident calculations, the pilot had a total flight experience of 1,714.9 hours. Although the pilot routinely logged actual and simulated instrument flight time, the recovered logbook pages did not include a previously accumulated total instrument flight time parameter that could be used to calculate his total instrument flight experience. According to the pilot’s son, the pilot was the only individual who flew the airplane. A postaccident review of ADS-B flight data associated with the airplane concluded that the pilot flew the airplane at least 26.1 hours during the year before the accident, 8.3 hours during the previous 6 months, 8.3 hours in the previous 3 months, and 5.7 hours during the month before the accident. The pilot flew at least 4.5 hours after his final logbook entry; when combined with his flight logbook information the pilot had a total flight experience of about 1,719.4 hours. On October 4, 2022, the pilot completed his last flight review and instrument proficiency check (IPC) in the airplane. According to the pilot’s flight logbook, during the 6 months following his last IPC he routinely logged the entirety of the flight as simulated instrument time and having completed one instrument approach every flight. However, the logbook entries did not provide the location and type of each instrument approach, nor the name of the individual who acted as the safety pilot while the pilot flew the airplane under simulated instrument conditions as required by 14 CFR 61.51. As such, the pilot’s recent instrument flight experience could not be adequately assessed with the available logbook evidence. According to a review of FAA medical records, the 73-year-old pilot’s last aviation medical examination was completed on September 18, 2016. At that time, he reported having high blood pressure and sleep apnea treated with a continuous positive airway pressure (CPAP) device. He reported taking the medications lansoprazole, valsartan/hydrochlorothiazide, tamsulosin, aspirin, fluticasone, and topical testosterone. The Aviation Medical Examiner (AME) noted glucose in the pilot’s urine. After discussion with the FAA Regional Flight Surgeon, the AME re-tested the pilot’s urine the next day and did not detect glucose. The AME then issued the pilot a third-class medical certificate via AME-Assisted Special Issuance (AASI) for sleep apnea and high blood pressure, with the limitations that the pilot must wear corrective lenses for distance and have glasses available for near vision. The medical certificate was not valid after September 30, 2017. The pilot subsequently completed the BasicMed course and the Comprehensive Medical Examination Checklist on September 17, 2021. A review of the pilot’s recent medical records indicated that he was being treated for high blood pressure, arthritis, back pain, insomnia, obstructive sleep apnea (OSA) and low testosterone. He also had extensive systemic steroid use for back pain and was prescribed muscle relaxants and narcotics and his OSA was being treated with a CPAP device. There was no information regarding the pilot’s CPAP usage and the machine was not recovered. No formal report was available for the results of the cardiac catheterization. At the request of the Dodge County Medical Examiner, the Fond du Lac County Chief Medical Examiner performed the pilot’s autopsy. According to the pilot’s autopsy report, his cause of death was multiple injuries. Due to the extent of the pilot’s injuries, structural evaluation of brain, heart and lungs was not possible. Within these limitations, the autopsy did not identify significant natural disease. At the request of the Medical Examiner, NMS Labs performed toxicological testing of muscle tissue from the pilot. Caffeine and acetaminophen were presumptively positive. Codeine was detected at 220 ng/g. Ethanol was not detected in muscle tissue at a reporting threshold of 0.08 g/hg. The FAA Forensic Sciences Laboratory performed toxicological testing of postmortem specimens from the pilot. Ethanol was detected in lung tissue at 0.022 g/hg and in muscle tissue at 0.059 g/hg. Gabapentin was detected in lung tissue at 5237 ng/g and in muscle tissue at 5028 ng/g. Codeine was detected in lung tissue at 403 ng/g and in muscle tissue at 139 ng/g. Hydrocodone was detected in lung tissue at 1 ng/g and was not detected in muscle tissue. Morphine was detected in lung tissue at 18 ng/g and in muscle tissue at 8 ng/g. Delta-8-tetrahydrocannabinol (delta-8-THC) was detected in lung tissue at 10.9 ng /g and in muscle tissue at 24 ng/g. Carboxy-delta-8 THC was detected in lung tissue at 34.4 ng/g and detected in muscle tissue at 9.8 ng/g. 11-hydroxy-tetrahydrocannabinol (11-hydroxy THC) was detected in lung tissue and was not detected in muscle tissue. Acetaminophen, valsartan, hydrochlorothiazide, and diclofenac were detected in lung and muscle tissue. Ethanol is a type of alcohol. It is the intoxicating alcohol in beer, wine, and liquor and, if consumed, can impair judgment, psychomotor performance, cognition, and vigilance. FAA regulation imposes strict limits on flying after consuming ethanol, including prohibiting pilots from flying with a blood ethanol level of 0.04 g/dL or greater. Alcohol consumption is not the only possible source of ethanol in postmortem specimens. Ethanol can sometimes be produced by microbes in a person’s b