ERA24FA072

A loss of engine power for reasons that could not be determined due to significant thermal damage from postimpact fire.

The pilot departed for a local flight shortly before the accident occurred. Recorded data showed that about 10 minutes into the flight, while about 3,000 ft mean sea level, groundspeed began to slow considerably, which was followed by a descent towards a large lake. The flight track continued over the lake and the loss of groundspeed and altitude also continued. A witness located near the accident site observed the airplane flying low over the water and then enter a right bank towards a tree line along the shoreline. The witnesses did not recall hearing any engine sounds. The airplane impacted the trees, then abruptly descended and impacted a parking lot. The airplane exploded on impact, and a large fire developed around the entire airplane. A distant surveillance camera captured the final moments of flight, which showed the airplane in a flight path consistent with the witness reports. Examination of the airframe and engine revealed no evidence of preimpact mechanical malfunctions or failures. Extensive thermal damage prevented the investigation from fully evaluating the airplane’s fuel system. About 10 gallons of fuel was recovered from the right main fuel tank. The other tanks were breached, destroyed, or empty of fuel. The fuel selector was not recovered. The thermal damage also prevented the recovery of any non-volatile memory stored in the cockpit primary and multi-function displays. Based on the available evidence, it is likely that the airplane’s engine lost power; however, here was no evidence that the engine experienced a catastrophic mechanical failure and there was sufficient fuel on-board. Due to the thermal damage sustained to the airplane, the reason for the loss of power could not be determined. The pilot’s severe coronary artery disease placed him at increased risk of a distracting, distressing, impairing, or incapacitating cardiovascular event, such as angina, arrhythmia, or heart attack. There is no autopsy evidence that such an event occurred, but such an event does not leave reliable autopsy evidence if it occurs just before death. Overall, there is insufficient evidence to determine whether the pilot’s severe coronary artery disease contributed to the accident. Postimpact fire provides a plausible explanation for the pilot’s carboxyhemoglobin result, particularly considering the possibility of some passive carbon monoxide absorption into cavity blood after death. The cyanide level in the pilot’s cavity blood likely was due to exposure to fire smoke, and was not likely due to engine exhaust exposure, because cyanide typically is produced by combustion of nitrogen-containing polymers. Overall, available postmortem evidence provides no clear indication that preimpact carbon monoxide or cyanide poisoning occurred, that in-flight fire occurred, or that the pilot breathed during the known fire.

According to maintenance records and Continental Motors factory records, the engine was factory assembled and packed on March 20, 2023, and installed on the airplane May 1, 2023. The most recent annual inspection was completed on May 1, 2023. The last maintenance entry in the engine logbook was on September 26, 2023, with an engine total time of 55.4 and an airplane Hobbs total time of 1,602. This maintenance inspection was for an oil change, which was performed by the accident pilot. The filter was also checked for contaminants, with none observed. According to the pilot’s operating handbook (POH), the airplane was equipped with two main wing fuel tanks that contained 37 gallons of usable fuel per tank. A visual measuring tab was attached to each filler neck of each individual cell. The bottom of the tab indicated 27 gallons of usable fuel in the cell, and the detent slot on the tab indicated 32 gallons of usable fuel in the cell. The engine-driven fuel injector pump delivers approximately 10 gallons of excess fuel per hour, which bypasses the fuel control and returns it to the cell being used. Fuel quantity is measured by float-operated fuel level sensors located in each wing tank system. These sensors transmit electrical signals to the engine and airframe interface to generate the left and right usable fuel quantity displayed in the engine and systems display portion of the MFD (Multi-Function Display). The fuel selector valve handle was located forward and to the left of the pilot’s seat. Takeoffs and landings must be made using the tank that is nearest full. The POH cautioned pilots to observe that the long, pointed end of the handle aligns with the fuel tank position being selected. According to FAA Airworthiness records, on April 19, 2010, the airplane was equipped with J.L. Osbourne tip tanks. They were installed in accordance with FAA supplemental type certificate STC SA4-1629. The airplane flight manual supplement detailed that the two tip tanks could contain 20 gallons of fuel to be transferred to the main fuel tanks. The tanks were to be loaded symmetrically. The normal procedures section stated that fuel could be transferred in level flight at approximately 25 gallons per hour per tank. The amount of fuel transferred to the main tanks should only occur once sufficient fuel was consumed from the main tanks. The cockpit contained a switch to start and stop the fuel transfer pumps. The POH’s provided the following emergency procedures: Figure 3: Emergency Airspeeds. According to the autopsy, conducted by Forensic Medicine Associates Inc., at the DeKalb County Forensic Science Center, Decatur, Georgia, the pilot’s cause of death was multiple blunt force injuries, with additional thermal injuries, and the manner of death was an accident. Evidence of atherosclerotic and hypertensive cardiovascular disease was identified, including plaque causing 75-99% narrowing of the right coronary artery, 50% narrowing of the left main coronary artery, 50% narrowing of the left anterior descending coronary artery, and 30% narrowing of the left circumflex coronary artery. Visual examination of the heart muscle did not identify other significant natural disease, although thermal injury was present. Toxicology testing performed by the FAA Forensic Sciences Laboratory, detected Carboxyhemoglobin at 10% and cyanide (1.46 ug/ml). The testing was also positive for losartan, and atorvastatin. The testing was negative for ethanol. Carboxyhemoglobin is formed when carbon monoxide binds to hemoglobin in blood, diminishing the blood’s ability to deliver oxygen to body tissues. Carbon monoxide is an odorless, tasteless, colorless, nonirritating gas that can be produced during hydrocarbon combustion. Exposure to carbon monoxide usually occurs by inhalation of smoke or exhaust fumes. Symptoms of low-level carbon monoxide exposure are nonspecific and variable, and may include headache, nausea, and tiredness. Increasing levels of exposure may become impairing or incapacitating, causing more serious neurocognitive, cardiac, and/or vision problems, progressing to death above carboxyhemoglobin levels of about 50% (or lower if other serious medical conditions co-exist), although symptoms are not simply predictable from carboxyhemoglobin levels. Cyanide is a fast-acting poison that interferes with cells’ ability to use oxygen. Cyanide may be produced as a byproduct of the combustion of nitrogen-containing polymers, which are found in a variety of goods including some plastics, upholstery materials, and synthetic rubbers. Cyanide exposure frequently occurs by inhalation during fires in which such goods are burning. Notably, the cyanide level can increase in pooled cavity blood that is passively exposed to atmospheric cyanide from fire after a person’s death. To a lesser extent, the carboxyhemoglobin level also can increase slightly in pooled cavity blood passively exposed to carbon monoxide from fire. Losartan is a prescription medication commonly used to treat high blood pressure. Atorvastatin is a prescription medication commonly used to control cholesterol and reduce cardiovascular risk. Losartan and atorvastatin are not generally considered impairing. On December 21, 2023, about 1714 eastern standard time, a Hawker Beechcraft Corp. G36 airplane, N23VS, was destroyed when it impacted terrain near Buford, Georgia. The private pilot was fatally injured. The airplane was operated by the pilot under the provisions of Title 14 Code of Federal Regulations Part 91 as a personal flight. According to the pilot’s family, the airplane was based at Dekalb-Peachtree Airport (PDK), Atlanta, Georgia, and the purpose of flight was to perform a local flight in the area. According to FAA ADS-B data, the airplane departed PDK at 1701 and navigated north, cruising at 3,000 ft mean sea level (msl). About 5 minutes into the flight, the flight track turned northeast toward Lake Lanier, Georgia, and the airplane continued to maintain 3,000 ft msl and about 160-170 knots groundspeed. At 1712:32, the flight track turned east and the airplane continued to maintain 3,000 ft msl, but groundspeed slowed to 98 knots. Subsequently, groundspeed and altitude began to decrease, and the flight track continued east over Lake Lanier. At 1714:19, the final position recorded was .1 mile north of the accident site. The airplane was about 100 ft above ground level, had turned to the right (south), and groundspeed was 70 knots. Figures 1 and 2 provide an overview of the final few minutes of the ADS-B flight track. Figure 1: Overview of the ADS-B flight track for the final few minutes of flight. Figure 2: Closer view of the ADS-B flight track for the final minute of flight. A witness near the accident site observed the airplane flying low over the water from west to east. He observed the airplane enter a right bank towards a tree line along the shoreline. The airplane subsequently impacted the trees, then abruptly descended and impacted a parking lot. Simultaneously with the impact, the airplane exploded, and a large fire developed around the entire airplane. Another witness near the accident site heard the airplane’s impact with trees. Neither witness heard the sound of an airplane engine. A distant surveillance camera captured the final moments of flight, and showed the airplane in a flight path consistent with the witness reports. The airplane’s position/ landing lights were on, the airplane was descending in a right bank, and subsequently exited the camera view. Immediately after exiting the camera view, an explosion was observed. Numerous fixed-base operators were requested to provide fuel receipts or fuel records for the accident airplane; however, no records were located for any recent time preceding the accident. The airplane impacted a line of trees along the Lake Lanier shoreline. A ground scar was located about 50 ft from the initial impact with tree