HISTORY OF FLIGHTOn June 26, 2023, about 0805 central daylight time (CDT), a Cessna 177 airplane, N3138T, was substantially damaged during an accident near Hot Springs, Arkansas. The pilot was fatally injured and the passenger sustained serious injuries. The airplane was operated as a Title 14 Code of Federal Regulations (CFR) Part 91 personal cross-country flight. According to the passenger, the pilot had recently purchased the airplane and they were flying it to their home base near Elizabethtown, Kentucky. The cross-country flight began from Las Cruces International Airport (LRU), Las Cruces, New Mexico, after a new interior was installed. On June 25, 2023, about 1435 (all times referenced as CDT), the cross-country flight departed LRU with the intended destination of Avenger Field Airport (SWW), Sweetwater, Texas. The flight landed at SWW about 1753 after being airborne for at least 3.3 hours. The passenger stated that despite the airplane being flown with the fuel selector set to both, the right fuel gauge indicated “empty” and the left fuel gauge indicated about “3/4” tank remaining after the flight from LRU to SWW. The passenger reported that the pilot refueled the airplane while at SWW. According to a fueling receipt, 25.8 gallons of 100 low-lead fuel were dispensed using the self-serve fuel pump at SWW. The passenger recalled that the airplane’s fuel tanks were completely full before the airplane departed SWW. According to flight track data, about 1849 the airplane departed SWW enroute to Memorial Field Airport (HOT), Hot Springs, Arkansas, as the intended destination. However, due to adverse weather that developed near HOT while enroute, the pilot diverted to J Lynn Helms Sevier County Airport (DEQ), De Queen, Arkansas. According to the passenger, the pilot set the engine speed to 2,300 rpm during cruise flight and when he attempted to lean the mixture the engine would begin “stumbling” when the mixture control was pulled 1.5 to 2 inches aft of full rich. Additionally, the passenger reported that they heard a “metal grinding” noise when the pilot activated the carburetor heat while on approach to the runway at DEQ. The pilot decided to go around and made an uneventful landing on the second approach. The flight landed at DEQ about 2143 after being airborne at least 2.9 hours. According to the passenger, after landing at DEQ the right fuel gauge indicated “empty” and the left fuel gauge indicated “1/4” tank remaining. The pilot and passenger overnighted in De Queen, Arkansas, before continuing onto HOT the following morning. According to the airport manager at DEQ, about 0714 on the morning of the accident, the pilot attempted to refuel the airplane using the airport’s self-serve fuel pump; however, despite the pilot’s credit card being processed there was no fuel dispensed and the credit card transaction was subsequently voided. The airport manager, who was not present at the time, stated that the self-serve fuel pump operated normally and there was fuel available when he tested it after the accident. The passenger stated that because the self-serve fuel pump did not dispense fuel, the pilot concluded that there was no fuel available. The pilot subsequently decided that the airplane had enough fuel for the flight from DEQ to HOT. The exact amount of fuel remaining on the airplane, as determined by the pilot, was not communicated to the passenger. However, the passenger opined that if the pilot was content with the amount of fuel remaining, then she was also satisfied with it. The passenger further noted that before they departed DEQ, the right fuel gauge still indicated “empty” and the left fuel gauge indicated “1/4” tank remaining. According to ADS-B flight track data, at 0724:36 the flight was on initial climb from runway 8 at DEQ. The airplane continued the climb to a final cruise altitude between 6,000 and 6,500 ft mean sea level (msl). According to recorded audio transmissions on the common traffic advisory frequency (CTAF) at HOT, at 0759:59 the pilot transmitted that the airplane was about 10 miles from the airport and that he intended to make a full-stop landing on runway 23. At that time, the airplane was approaching HOT from the southwest, as depicted in figure 1. At 0802:15 the pilot transmitted on the CTAF that the airplane was “low on fuel” and that he intended to land on runway 5. At that time, the airplane was about 3,700 ft msl and 5.3 statute miles (sm) west-southwest of the runway 5 threshold at HOT. At 0804:35 the pilot transmitted, “… engine out, coming in runway five, engine out.” At that time, the airplane was about 1,100 ft msl, or about 600 ft above the runway 5 threshold elevation, and 1.8 sm west-southwest of the runway. Airplane performance calculations using ADS-B flight track data indicated that the airplane’s calibrated airspeed was about 63 mph when the pilot transmitted that the airplane had a loss of engine power, as depicted in figure 2. According to the passenger, the pilot was unable to restore engine power by ensuring the primer was properly stowed and locked, the ignition/start switch was selected to both magnetos, the carburetor heat was on, the throttle was full forward, the mixture control was full forward, and the fuel selector was on both. The passenger stated that the pilot pitched the airplane for best glide speed, and she assisted by moving the pitch trim to a “full nose up” position. Figure 1. Plot of airplane flight track data. Figure 2. Plots of airplane altitude, ground speed, true airspeed, calibrated airspeed, and vertical speed. Figure 3. Plots of airplane heading, roll angle, and flight path angle. At 0805:27, the final recorded ADS-B track point was about 600 ft msl (200 ft agl) and 0.8 sm from the runway 5 threshold. The airplane was about 0.16 sm west-southwest of the point-of-impact with the lake. Airplane performance calculations using ADS-B track data indicated that the airplane was at a calibrated airspeed of about 61 mph, descending about 450 feet per minute (fpm), and was nearly wings level, as depicted in figure 2 and figure 3. The passenger stated that she lost sight of the airport as the airplane descended over the lake. According to the passenger, the pilot intended to land on the lake to avoid the trees and houses that surrounded the lake. However, while above the lake, the airplane “stalled” as it descended through tree top height. The aerodynamic stall resulted in the airplane nose dropping almost straight down. The passenger stated that the airplane immediately started to sink after it impacted the lake. She recalled remaining conscious but unable to see anything in the murky green lake water. Believing that she would drown, she instinctively unfastened her seat belt and swam to the surface. The pilot did not emerge from the submerged airplane. After the accident, the passenger told at least one individual who provided her assistance that the airplane ran out of fuel while on approach to the airport. PERSONNEL INFORMATIONA review of the pilot’s flight logbook established that he began his flight training on September 3, 2011, and received his private pilot certificate on November 2, 2012, with 74.1 hours total flight experience. The final logbook entry was dated June 18, 2023, at which time he had 147.4 hours total flight experience. The entirety of his logged flight experience was flown in Cessna 172 airplanes. The pilot’s last regulatory flight review was completed on October 7, 2022. Based on available flight track data, the pilot flew three additional flights after his final logbook entry. The three flights were flown after he purchased the accident airplane. On June 25, 2023, the pilot flew a 3.3-hour flight from LRU to SWW and a 2.9-hour flight from SWW to DEQ. Then, on the day of the accident, the pilot flew the 0.7-hour flight from DEQ to HOT. The combined 6.9 hours was the pilot’s only flight experience in a Cessna 177 airplane. When the pilot’s logged flight time was combined with the three additional flights, he had 154.3 hours total flight experience, of which 142.3 hours were flown as pilot-in-command. The pilot had flown 11.6 hours in the previous year, 9.6 hours in the previous 6 months, 8.4 hours during the past 90 days, and 7.4 hours during the 30 days before the accident. AIRCRAFT INFORMATIONA review of available maintenance documentation established that the airframe, engine, and propeller had accumulated 2,610.9 hours since new. The engine had accumulated 1,103.5 hours since the last top overhaul. The airplane had accumulated 171.4 hours since the last annual inspection completed on August 31, 2022. According to the Cessna 177 Owner’s Manual, the airplane was equipped with a 49-gallon capacity (48 gallons usable) fuel system, consisting of two 24.5-gallon wing fuel tanks (24 gallons usable each). The fuel selector valve positions included left, right, both, and off. The airplane’s expected fuel consumption rate was 8 to 8.5 gph if the engine was operated at 75% brake horsepower and properly leaned for cruise flight, yielding an airplane fuel endurance of 5.7 to 6 hours. Alternatively, if the engine was operated at less than 75% brake horsepower and leaned for cruise flight, the expected fuel consumption rate was 6 to 8 gph and the fuel endurance was 6 to 8 hours. The airplane had a glide ratio of about 10:1 when flown at the best glide speed of 80 mph, with the flaps retracted, a windmilling propeller, and zero wind. The engine-off, wings-level, aerodynamic stall speed at maximum gross weight with fully extended flaps was 53 mph. Similarly, the stall speed was 64 mph with the flaps fully retracted. AIRPORT INFORMATIONA review of available maintenance documentation established that the airframe, engine, and propeller had accumulated 2,610.9 hours since new. The engine had accumulated 1,103.5 hours since the last top overhaul. The airplane had accumulated 171.4 hours since the last annual inspection completed on August 31, 2022. According to the Cessna 177 Owner’s Manual, the airplane was equipped with a 49-gallon capacity (48 gallons usable) fuel system, consisting of two 24.5-gallon wing fuel tanks (24 gallons usable each). The fuel selector valve positions included left, right, both, and off. The airplane’s expected fuel consumption rate was 8 to 8.5 gph if the engine was operated at 75% brake horsepower and properly leaned for cruise flight, yielding an airplane fuel endurance of 5.7 to 6 hours. Alternatively, if the engine was operated at less than 75% brake horsepower and leaned for cruise flight, the expected fuel consumption rate was 6 to 8 gph and the fuel endurance was 6 to 8 hours. The airplane had a glide ratio of about 10:1 when flown at the best glide speed of 80 mph, with the flaps retracted, a windmilling propeller, and zero wind. The engine-off, wings-level, aerodynamic stall speed at maximum gross weight with fully extended flaps was 53 mph. Similarly, the stall speed was 64 mph with the flaps fully retracted. WRECKAGE AND IMPACT INFORMATIONThe airplane sustained substantial damage when it impacted lake water in a near-vertical, nose-down pitch attitude. The airplane sank and was found inverted in 7 to 13 ft of water. The accident site was about 0.66 sm west-southwest of the runway 5 threshold at HOT. Wreckage recovery personnel floated the airplane to the surface and towed it to a public boat launch where it was recovered to shore, as shown in figure 4. Figure 4. Airplane wreckage after it was recovered to a boat launch. Airframe Both wings remained attached to their respective fuselage attachment points. The leading edge of both wings were crushed aft. The cockpit windshield and the back window were separated. The left cabin door separated from the fuselage and was not observed during the examination. The engine cowling separated from the nose and was not observed during the examination. All flight control surfaces remained attached to their respective hinge points. Flight control cable continuity was confirmed from the cockpit controls to their respective flight control surface. The flap actuator jackscrew was found fully extended consistent with the wing flaps fully extended at impact. The stabilator trim actuator extension measured about 1.5 inches, which corresponded with about 10° stabilator trim tab trailing edge down (nose-up trim). However, impact-related damage to the aft fuselage during impact and wreckage recovery could have altered the position of the stabilator trim actuator position due to changes in cable tension. Fuel System The wing fuel tanks did not contain any fuel after the airplane was salvaged from the lake. Fluid samples recovered from various points in the fuel system were consistent with mostly lake water but also exhibited an odor consistent with 100 low lead aviation fuel. The lake water and fuel did not separate after the samples sat undisturbed for more than 3 hours. The fuel selector valve was positioned to use fuel simultaneously from both tanks. The fuel selector valve functioned as designed, with a positive detent felt in all selector positions. The firewall-mounted fuel shutoff valve was found in a partially open position. The fuel shutoff valve control cable remained attached to the control arm, but the control cable was bent upward consistent with impact-related damage. The entire airframe fuel system was tested by blowing air through the fuel supply lines and vent lines. The fuel lines and vent lines were free of obstructions. The vented fuel caps on both wing fuel tanks exhibited no cracks and the rubber seals/flaps were in good condition. The airplane was equipped with a filler neck guard in each fuel tank filler port. The wingtip vent check valves were not obstructed and functioned as designed. The electric auxiliary fuel pump contained water and was not tested. The cockpit switch for the electric auxiliary fuel pump was in the off position. The fuel quantity transmitters’ resistance values were tested with a digital multimeter; however, notably, after the accident both wings and their respective fuel transmitters were submerged in lake water. There were no electrical shorts observed in the full range of either fuel float switch. Engine The engine remained attached to the airframe mounts but was displaced aft and down, as shown in figure 5. Internal engine continuity and valvetrain continuity were confirmed while the crankshaft was rotated. Cylinder compression was confirmed by placing a finger over the open spark plug holes and feeling suction and expelled air from each cylinder while the crankshaft was rotated. Borescope examination of each cylinder did not reveal any anomalies with the cylinders, pistons, valves, or valve seats. The exhaust and intake tubes were removed to facilitate the engine examination. Sediment was found in one exhaust riser, but no exhaust obstructions were observed. The intake tubes exhibited significant fuel staining and black deposits in each pipe; an example is shown in figure 6. Fuel staining was also observed on the exterior of the No. 2 cylinder tube at the mounting gasket to the cylinder. Figure 5. Engine and propeller. Figure 6. Intake tube with fuel staining. The carburetor remained attached to the bottom of the engine sump. The exhaust was pressed up against the throttle control lever. The throttle control cable remained attached to the carburetor, with the throttle plate in a mostly closed position. The mixture cable was impact separated from the mixture arm. An impact-related witness mark on the carburetor was found from the mixture control lever in the full rich position. The carburetor throttle plate was mostly closed and had evidence of fuel staining on the back (engine sump side) of the plate, as shown in figure 7. Fuel staining was only observed on the engine side of the throttle plate. The accelerator pump jettisoned water into the carburetor throat when the throttle arm was actuated. The carburetor fuel inlet screen contained organic debris; however, the fuel inlet line fitting had sheared and exhibited impact-related damage. The metal floats in the fuel bowl exhibited metal hydraulic deformation. The carburetor heat control knob and control cable were found pulled aft about 2 inches and bent down. The other end of the carburetor heat cable exhibited impact-related damage. The fractured end of the carburetor heat cable included the solid shaft of the carburetor heat butterfly valve. The carburetor heat ducting and valve were not recovered with the wreckage. Figure 7. Fuel staining on throttle plate and carburetor throat. The left magneto remained attached to the accessory housing. The left magneto produced spark at all four leads when rotated by hand. The impulse coupling functioned normally. The right magneto was impact separated from the accessory housing at the mounting flange. The right magneto produced spark at all four leads when rotated by hand. The right-magneto was not equipped with an impulse coupling. The bottom spark plugs were removed upon the wreckage recovery to the shore to allow water to drain from the cylinder heads. The No. 3 cylinder top spark plug exhibited blue staining on the insulating ceramic, as shown in figure 8. The remaining spark plugs exhibited features consistent with normal engine operation. Figure 8. Cylinder No. 3 top spark plug. The engine-driven fuel pump functioned normally when tested by hand. The vacuum pump remained secured to the accessory housing and appeared undamaged. The unit was removed and pumped water out when rotated by hand. The shear shaft was not damaged. The oil suction screen remained secured to the sump and was not obstructed. The oil filter base was broken away from the accessory housing. The oil filter was slightly crushed forward into the filter base. The airplane air filter appeared deteriorated and dirty. The sealing gasket of the airbox was deteriorated and missing sections of gasket material. Propeller The propeller remained attached to the crankshaft flange and spacer. The spinner displayed fore-to-aft crush damage. The propeller blades exhibited slight twist and light chordwise scratch marks. The leading edge of both propeller blades exhibited minor scratches. ADDITIONAL INFORMATIONAccording to 14 CFR 91.151, no person may begin a flight in an airplane under day visual flight rules conditions unless, after considering wind and forecast weather conditions, there is enough fuel to fly to the first point of intended landing plus an additional 30 minutes at a normal cruising speed. MEDICAL AND PATHOLOGICAL INFORMATIONAccording to a review of FAA medical records, the 49-year-old pilot’s last aviation medical examination was completed on March 8, 2012. At that time, the pilot reported having high blood pressure (hypertension) and a prescription for lisinopril. Lisinopril, an angiotensin-converting enzyme (ACE) inhibitor medication used to treat hypertension, is acceptable for pilot use. The pilot was issued a third-class medical certificate without limitation. The medical certificate was not valid after March 31, 2017. The pilot subsequently completed the BasicMed Comprehensive Medical Examination Checklist on August 16, 2022, and the BasicMed online course on October 12, 2022. The Arkansas State Medical Examiner’s Office performed the pilot’s autopsy. According to the pilot’s autopsy report, the cause of death was drowning associated with multiple blunt force injuries, and the manner of death was accident. FAA toxicology testing detected delta-8-tetrahydrocannabinol (delta-8-THC) in peripheral blood at 6.4 ng/mL and in urine at 5.9 ng/mL. Carboxy-delta-8-THC was detected in peripheral blood at 142.7 ng/mL and in urine at 1,278.5 ng/mL. 11-hydroxy-THC was detected in peripheral blood and urine. Diphenhydramine was detected in peripheral blood at 104 ng/mL and in urine at 1,588 ng/mL. Fluoxetine was detected in peripheral blood at 1,044 ng/mL and in urine at 827 ng/mL. Norfluoxetine was detected in peripheral blood at 1,243 ng/mL and detected in urine at 970 ng/mL. Metoprolol and atorvastatin were detected in peripheral blood and urine. Lisinopril was detected in urine and was not detected in peripheral blood. Carboxyhemoglobin and ethanol were not detected in blood. Delta-8-THC is a psychoactive cannabinoid chemical. Although delta-8-THC is similar to the primary psychoactive chemical in cannabis (delta-9-THC), very little delta-8-THC is present in the cannabis plant. Delta-8-THC used in consumer products typically is chemically manufactured from cannabidiol (CBD), another chemical in the cannabis plant. Delta-8-THC products are often marketed as “hemp” products, which consumers may not associate with psychoactive effects. Delta-8-THC is available in a variety of over-the-counter products for oral consumption, smoking, and inhalation. Delta-8-THC has psychoactive and intoxicating effects that can impair motor coordination, reaction time, decision making, problem solving, and vigilance. The potency and purity of delta-8-THC varies widely in consumer products. Delta-8 THC products may contain impurities including delta-9 THC. Delta-8 THC products have not been evaluated or approved by the Food and Drug Administration for safe use in any context. Carboxy-delta-8-THC is a non-psychoactive metabolite of delta-8-THC. 11-hydroxy THC is a psychoactive metabolite of both delta-8-THC and delta-9-THC (the FAA Forensic Sciences Laboratory does not distinguish between 11-hydroxy-delta-8-THC and 11-hydroxy-delta-9-THC). Diphenhydramine is a sedating antihistamine medication widely available over the counter in multiple sleep aids and cold and allergy products. Diphenhydramine may cause cognitive and psychomotor slowing and drowsiness. It typically carries a warning that it may impair performance of tasks like driving and operating heavy machinery. The therapeutic range of diphenhydramine in the plasma of living persons is about 25 ng/mL to 100 ng/mL. The blood to plasma ratio for diphenhydramine is reported to be 0.7 to 0.8. The FAA recommends a 60-hour waiting period from the last dose of diphenhydramine to piloting an aircraft, to allow sufficient time for the drug to be cleared from circulation. Fluoxetine is a prescription selective serotonin reuptake inhibitor (SSRI) antidepressant medication that may be used for treating depression, panic disorders, and bipolar disorders. The FAA considers fluoxetine, used as a single agent, to be conditionally approved for medical certification by Special Issuance if the pilot is otherwise qualified, subject to case-by-case evaluation of the underlying condition and its treatment. Norfluoxetine is a metabolite of fluoxetine.