ERA24FA365

The flight instructor was conducting a dual instructional flight with the student pilot. The accident flight was the flight instructor’s third flight in the airplane make and model and the student pilot’s second dual instructional flight. Recorded flight track data showed that, after departure, the airplane remained within 15 miles of the airport and proceeded in maneuvering flight consistent with a private pilot training profile. During the final 5 minutes of the flight, the airplane turned to and maintained a northeasterly heading for about 4 minutes, followed by a turn to the east, and then to the north. The last recorded ADS-B data showed a gradual left turn about 150 ft above the ground, with a groundspeed of about 74 to 78 mph. The stall speed for the airplane with flaps up and 20° of bank was about 64 mph (indicated airspeed). The last recorded ground track location was about 250 ft east-southeast of the accident site. The airplane impacted wooded terrain at a steep, nose-low attitude, consistent with an aerodynamic stall. The flight instructor and the student pilot were fatally injured and there were no known witnesses to the accident. A postaccident examination of the flight controls did not reveal evidence of a preexisting mechanical malfunction or failure. Both wing fuel tanks were breached, and the airplane’s fuel state at the time of the accident could not be determined from available information. Although no anomalies were found during the examination of the engine and fuel system, the propeller showed no signs of powered rotation at impact. Additionally, the temperature and dew point near the accident site were conducive to the formation of serious carburetor icing at glide (idle) power. Although the carburetor heat knob was found full forward (cold) position, it was partially broken off and the portion of the instrument panel surrounding the knob showed impact deformation; accordingly, the preaccident use of carburetor heat couldn’t be determined. At the time of the accident, the flight instructor did not hold a current Federal Aviation Administration (FAA) -issued medical certificate; however, based on the accident circumstances, the instructor’s impairment or incapacitation from a medical issue was unlikely. Postmortem toxicological testing results indicated that the student pilot had used one or more cannabis products and may have been experiencing associated impairing psychoactive effects during the flight. However, considering the accident circumstances, the student pilot’s limited baseline skill and experience, his limited flight safety responsibilities on the accident flight, and the presence of the flight instructor, it is unlikely that effects of his cannabis use contributed to the accident. Additionally, the low levels of ethanol detected in vitreous fluid indicated that some or all of the detected ethanol may have been from postmortem production rather than alcohol consumption; accordingly, ethanol was also unlikely tohave contributed to the accident. The flight track data showed that, during the final minute of the flight, the airplane passed near the end of two fields before it turned over a wooded area toward a clearing, consistent with an attempt to glide the airplane to an area to perform a forced landing. The airplane’s relatively low speed during these final moments of the flight, coupled with the lack of powered rotational signatures observed on the propeller after the accident, suggest that the airplane’s engine may have lost power, though no evidence of any mechanical malfunction or failure of the engine were observed during the postaccident wreckage examination. The airplane’s fuel state and the flight instructor’s use of carburetor heat at the time of the accident could not be determined based on the available information. It is likely that, during this attempted approach, the flight instructor allowed the airplane’s airspeed to decay, which resulted in the exceedance of the airplane’s critical angle of attack and an aerodynamic stall.

The flight instructor was recently hired by the operator, Flying Tigers Flight School. He received a local checkout flight in the Grumman AA-5 on July 31, 2024, from a school flight instructor. He flew a dual instruction flight with the accident student pilot on August 28, 2024, logging 0.9 hour. The accident flight was the flight instructor’s third flight in the Grumman AA-5 and the second flight with the accident student pilot. The flight instructor’s last aviation medical examination was May 9, 2019. At that time, he reported no medication use and no active medical conditions and was issued a third-class medical certificate without limitation. At the time of the accident, he did not hold a current FAA medical certificate. The student pilot’s only logged flying experience was the August 28 flight, which he flew with the accident flight instructor. The wreckage came to rest in a steep, nose-low attitude on a heading of 270°. There was no evidence of fire. All components of the airplane were located within the wreckage debris field. The forward fuselage was crushed aft, compromising the cockpit area. The cockpit canopy was cut away and placed aside by first responders. The canopy plexiglass was fractured into multiple pieces. The mixture control was found about 3/4 inch aft (leaned) from full forward. The throttle was found full forward. The carburetor heat knob was found full forward (cold) but was partially broken off, and the panel surrounding the knob showed impact deformation. The fuel selector valve was found in the RIGHT tank position. Both wings remained attached to the fuselage, and the tubular through-spar was intact except for some bending and crushing from ground impact. The left wing was buckled upward about midspan. The leading-edge skin was crushed upward and aft and partially separated from the ribs. The left flap was separated from the wing attachment points and was located on the ground under the left wing. The left aileron was partially attached to the wing with the outboard attachment point intact and the inboard attachment point separated consistent with overload. Aileron and flap control continuity was confirmed from the control surfaces with the exception of overload separations. The left wing fuel tank was breached, and no residual fuel was found. The leading-edge skin of the right wing was crushed upward and aft and partially separated from the ribs. The right flap remained attached to the wing with the trailing edge pushed up in a near-vertical position. The right aileron remained attached to the wing. Aileron and flap control continuity was confirmed from the control surfaces to the cockpit except for overload separations. The right wing fuel tank was breached, and no residual fuel was found. The empennage sustained minimal impact damage. Control continuity was established from the elevator and rudder surfaces to the cockpit except for cable cuts made by recovery personnel. Elevator trim tab control continuity wasestablished to the cockpit, and the tab and was found about 10° tab up. Examination of the electric fuel boost pump’s internal fuel screen revealed it was clean and clear. The pump operated normally when energized using the airplane’s battery. Examination of the engine at a recovery facility revealed the crankshaft flange and propeller were impact-separated from the engine. The left crankcase nose was fragmented from impact. The exhaust muffler was removed and observed to be unobstructed. The pushrod tubes were impact-damaged. The carburetor and engine-driven fuel pump remained attached to the engine. Both magnetos were impact-separated. Partial disassembly of the engine enabled visual confirmation of continuity of the crankshaft to the rear gears. No damage to the pistons, cylinders, valves, connecting rods, or rod bearings was observed. The oil sump and accessory case were removed, and the crankcase halves were separated. No damage to the camshaft was noted. Removal and partial disassembly of the carburetor revealed a small amount of liquid drained from the carburetor fuel hose when it was disconnected. No liquid was observed in the carburetor float bowl. No damage to the brass floats or other carburetor internal parts was noted. The carburetor fuel inlet screen was absent of debris. The engine-driven fuel pump drained liquid with an odor consistent with aviation gasoline when the pump was removed from the engine and tilted. The pump produced air from the outlet port when actuated by hand. Partial disassembly revealed no damage on the rubber diaphragms, internal check valves, or other internal components. Liquid was observed in the pump cavity. Both magnetos produced spark from all ignition towers when rotated using an electric drill. The spark plug electrodes exhibited gray coloration and normal wear condition when compared to a Champion Check-a-Plug chart. The bottom spark plug electrodes for the No. 1 cylinder were oil-soaked. The engine ignition harness was impact-damaged. Oil was observed in the engine. The oil suction screen and the oil filter media were absent of metallic debris. Examination of the propeller revealed overload signatures where it was separated from the crankshaft flange. Wood fibers were observed imbedded in the spinner nose. No discernible bending, twisting, chordwise scratches, or leading-edge damage were noted on either propeller blade (see figure 2). Figure 2. Propeller and spinner. FAA Advisory Circular 20-113, “Pilot Precautions and Procedures to be Taken in Preventing Aircraft Reciprocating Engine Induction System and Fuel System Icing Problems,” stated that, “to prevent accident due to induction system icing, the pilot should regularly use [carburetor] heat under conditions known to be conducive to atmospheric icing and be alert at all times for indications of icing in the fuel system.” The advisory circular recommended that, when operating in conditions where the relative humidity is greater than 50% and thetemperature is below 70°F, “[carburetor] heat should be applied for a short time to warm the induction system before beginning a prolonged descent with the engine throttled and left on during the descent. Power lever advancement should be performed periodically during the descent to assure that power recovery can be achieved.” According to FAA SAIB CE-09-35, “carburetor ice can be detected by a drop in [engine speed] in fixed-pitch propeller airplanes… [and] usually there will be a roughness in engine operation.” Per the airframe manufacturer’s data, the total capacity for each wing fuel tank was 19 gallons, about 18.5 gallons of which was usable. According to the operator, the airplane’s fuel consumption was about 9 gallons per hour. Based on fueling records from PUJ, as well as airplane flight logs and information provided by the operator, the airplane was last fueled to capacity on September 1, 2024, then flew two flights, 1.7 and 1.6 hours, respectively. On September 2, 2024, the airplane was serviced with 10 gallons of fuel, then flew two flights, 0.8 and 0.4 hour, respectively. On September 3, 2024, the airplane was serviced with 5 gallons of fuel, then flew 0.8 hour. There was no record of fueling on the day of the accident. A review of the pilot’s operating handbook (POH) showed that the stall speed for the airplane with flaps up and 20° of bank was about 64 mph (indicated airspeed). On September 4, 2024, about 1121 eastern daylight time, a Grumman American Aviation Corporation AA-5 airplane, N9659L, was substantially damaged when it was involved in an accident near Rockmart, Georgia. The flight instructor and the student pilot were fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 instructional flight. ADS-B data revealed that the airplane departed runway 13 at Paulding Northwest Atlanta Airport (PUJ), Dallas, Georgia, about 1033. The airplane proceeded to the west and remained within 15 miles of PUJ. The airplane continued in maneuvering flight between 2,500 ft and 4,000 ft mean sea level, consistent with a private pilot training profile. About 1116, the airplane turned to and maintained a northeast heading for about 4 minutes, then it turned east at 1,800ft msl and headed over wooded terrain toward the south end of a field. In the final minute of the flight, the airplane passed off the south end of that field then it turned in a northerly direction at 1,300ft msl and passed over a second field before it headed over wooded terrain. Based on the last recorded ADS-B data and terrain elevation information, the airplane then made a gradual left turn about 150 ft above the ground. The main wreckage was found in a wooded area about 250 ft west-northwest of the last recorded location. It was adjacent to a two-lane road and about 1,000 ft east-southeast of a clearing in the woods that was about 550 ft long and 500 ft wide. The airplane’s ground speed during the last 2 to 3 seconds of the flight wasabout 74 to 78 mph (see figure 1). North heading at 1300 ft msl at 1121:00 South end of second field at 1200 ft msl 1121:11 South end of first field at 1500 ft msl 1120:42 Easterly heading at 1800 ft msl at 1120:05 Figure 1. ADS-B ground track and accident site. The pilots were not in communication with air traffic control at the time of the accident, and there were no known distress calls received from the airplane. There were no known witnesses to the accident. The Georgia Bureau of Investigation, Division of Forensic Sciences, Medical Examiner’s Office, performed the flight instructor’s autopsy. According to the autopsy report, the flight instructor’s cause of death was multiple blunt impact injuries, and his manner of death was accident. His autopsy did not identify significant natural disease. The FAA Forensic Sciences Laboratory performed toxicological testing of postmortem specimens from the flight instructor. No tested-for substances were detected (except for urine glucose, which is measured routinely and was normal). The Georgia Bureau of Investigation, Division of Forensic Sciences, Medical Examiner’s Office, performed the student pilot’s autopsy. According to the autopsy report, the student pilot’s cause of death was multiple blunt impact injuries, and his manner of death was accident. His autopsy did not identify significant natural disease. The autopsy report noted that a rapid tabletop drug screen was positive for tetrahydrocannabinol (THC). The FAA Forensic Sciences Laboratory performed toxicological testing of postmortem specimens from the student pilot. Ethanol was detected at 0.014 g/dL in cavity blood and was not detected in vitreous fluid or urine. N-propanol was detected in cavity blood and urine and was not detected in vitreous fluid. Delta-9-THC was detected at 7.3 ng/mL in cavity blood and was not detected in urine. Eleven-hydroxy-THC was detected at 1 ng/mL in cavity blood and at 10.8 ng/mL in urine. Carboxy-delta-9-THC was detected at 17.7 ng/mL in cavity blood and at 559.9 ng/mL in urine. Cannabidiol (CBD) and cannabigerol (CBG) were detected in cavity blood and urine. 7-hydroxy-CBD, 7-carboxy-CBD, and tetrahydrozoline were detected in urine and were not detected in cavity blood. Ethanol 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 a prohibition on piloting a civil aircraft while having 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 sometimes may be produced by microbes in a person’s body tissues and fluids after death, potentially elevating ethanol levels in some postmortem specimens but not others. Vitreous fluid typically is less susceptible to postmortem ethanol production than are other specimen types. Based on the reported conditions at thePUJ about the time of the accident, the temperature and dew point about 5 nm from the accident site were about 71.6° and 51.8° F, respectively. The calculated relative humidity for these conditions was about 49.7%. Review of the carburetor icing probability chart contained within FAA Special Airworthiness Information Bulletin (SAIB) CE-09-35 revealed that these conditions were conducive to the formation of serious icing at glide power.