HISTORY OF FLIGHTOn May 24, 2023, about 1101 central daylight time, a Cessna 182T airplane, N577TZ, sustained substantial damage when it was involved in an accident near Grand Isle, Louisiana. The pilot was fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 aerial observation flight. According to company information and ADS-B data, the pilot departed his home base of Ocean Springs, Mississippi, about 0805 for a routine fish spotting flight. ADS-B data indicated that the pilot performed several low-level flight maneuvers for about 3 hours that were consistent with aerial observation for fish spotting activities. During the flight, about 1030, the pilot made radio contact with a boat captain to coordinate a short flight to the west of the boat to scout fish locations. The boat captain stated the pilot seemed upset, agitated, and discouraged due to some unknown issue that occurred the day before. During the radio communications, the pilot stated several swear words and inappropriate language, which was extremely abnormal for the pilot and in violation of company policy. The pilot descended to about 500 ft above ground level near Cat Island, and the boat captain could tell the pilot was still upset. The boat captain told the pilot to go land the airplane and take a break. The pilot stated he was going to fly to the north and that was the last communication the boat captain had with the pilot. About 1104, the boat captain texted the pilot to let him know he was not going to fish to the west; there was no response from the pilot. The last ADS-B contact showed the airplane about 1.8 miles offshore on a southwest heading about 175 ft above the ocean water (see figures 1 and 2). Figure 1. ADS-B data showing the end of the flight track. Figure 2. ADS-B data showing the end of the flight track. There were no emergency or distress calls received from the accident airplane. Based on company flight tracking information, company personnel notified the US Coast Guard about a missing airplane and a search was initiated. The pilot’s body was located the following morning near a coastline, but the airplane was not located. On June 6th, a shrimp boat fishing net caught the airplane. Unable to raise the airplane onto the boat, the shrimp boat captain cut the net and noted the location. On June 11th, a majority of the airplane wreckage was recovered about 1.8 miles offshore of Grand Isle in about 15 ft of water. WRECKAGE AND IMPACT INFORMATIONThe extent of airframe damage during the water impact was unknown due to ocean tide activity, the shrimp boat net entangling the wreckage, and subsequent recovery operations. The fuselage was recovered in about four main sections: forward fuselage, mid-fuselage, empennage, and left wing. The right wing, two cabin doors, lower engine cowling, and a portion of the upper rudder surface were not located. The forward fuselage, which included the engine and propeller assembly, sustained underside crush damage. The nose landing gear strut was bent and pushed aft about 60° into the firewall and forward fuselage floor. The forward fuselage floor was bent and distorted (see figure 3). Neither forward seat restraint was found secure in their respective buckle assemblies. The fuel selector valve was found in the BOTH fuel tank position, and fuel was noted in the valve. A damaged can of White Claw Hard Seltzer, which appeared to be unopened, was located behind the instrument panel. Figure 3. Right side of forward fuselage, engine, and propeller assembly. Flight control continuity was established from the mid-fuselage section to the cockpit controls. Disconnects in the flight control cables and system were consistent with impact and recovery operations. The left-wing flap was recovered in the extended position, and the flap push/pull rod was bent and prohibited the flap from retracting. The right flap and flap actuator were not recovered. The elevator trim tab measured about 10° tab down (nose up). The engine remained attached to the engine mount, and the propeller remained attached to the engine. Corrosion and ocean silt debris were noted on the engine. The engine fuel pump, fuel flow divider, fuel servo lines, and fuel servo contained evidence of fuel. The propeller was manually rotated; thumb compression was noted on all 6 cylinders, and mechanical continuity was noted throughout the engine. Postaccident examination of the airplane revealed no evidence of any preimpact mechanical malfunctions or failures that would have precluded normal operation. MEDICAL AND PATHOLOGICAL INFORMATIONAn autopsy of the pilot was performed by the Jefferson Parish Forensic Center, Harvey, Louisiana. According to the autopsy report, the cause of death was multiple blunt force injuries and drowning, and the manner of death was accident. The FAA Forensic Sciences Laboratory performed toxicological testing on postmortem specimens from the pilot. No drugs of abuse were detected. Ethanol was detected in cavity blood at 0.278 g/dL, in vitreous fluid at 0.245 g/dL, in muscle tissue at 0.249 g/dL, and in brain tissue at 0.283 g/dL. N-propanol was detected in cavity blood and brain tissue and was not detected in vitreous fluid or muscle tissue. N-Butanol was detected in cavity blood and was not detected in vitreous fluid, muscle tissue, or brain tissue. Ethanol is a type of alcohol. It is the intoxicating alcohol in beer, wine, and liquor, and if consumed, can impair judgement, cognition, and vigilance. Performance impairing effects can include worsening judgement and reaction times, alterations in perception of the environment, poor coordination and changes in behavior and mood. Performance-impairing effects worsen as blood levels of ethanol increase. Once consumed, ethanol is absorbed into circulation and rapidly distributes into total body water, resulting in relatively similar ethanol levels in various body tissues. Alcohol consumption is not the only possible source of ethanol in postmortem specimens. Ethanol can sometimes be produced by microbes in a person’s body after death. Postmortem ethanol production is made more likely by extensive traumatic injury. Vitreous fluid generally is better protected from postmortem microbial spread and therefore is less susceptible to postmortem ethanol production than other specimen types. FAA regulations impose strict limits on flying after consuming ethanol, including prohibiting pilots from flying with a blood ethanol level of 0.04 g/dL or greater. N-propanol and n-butanol are other alcohols that can be produced by microbes in a person’s body after death. Their presence is a postmortem specimen, which is potentially indicative of postmortem microbial activity in the specimen but does not reliably indicate that postmortem ethanol production occurred.