CEN24FA188

The student pilot’s failure to maintain airplane control while practicing a power-on stall, which resulted in an inadvertent spin at an altitude from which he was unable to recover.

The student pilot was conducting a local solo flight. Review of flight track data revealed that, during the final 6.5 minutes of the flight, the airplane completed several large deceleration-and-acceleration cycles between 1,000 and 1,700 ft above ground level (agl). During each of these cycles, the airplane’s airspeed decreased below aerodynamic stall speed before it increased again. The airspeed and altitude profiles during these maneuvers were consistent with the pilot practicing aerodynamic stalls. Shortly before the accident, the airplane entered a rapid climb while the airspeed decreased below aerodynamic stall speed, consistent with an intentional power-on stall entry. There was a 6-second interruption in track data coverage after the airplane entered the aerodynamic stall, but when coverage resumed, the airplane was in a rapid descent that continued until the end of recorded data about 8 seconds later. A witness reported seeing the airplane flying at slow speed, almost “hovering” in the air, before it suddenly entered a spiraling nosedive. The airplane completed at least 6 to 8 rotations in the descending spiral before it descended out of sight behind a hill. An extensive postimpact fire thermally damaged most of the airplane. A wreckage examination revealed no evidence of a preimpact mechanical malfunction or failure that would have prevented normal airplane operation. The pilot’s autopsy and postmortem toxicology tests did not reveal any evidence of medical incapacitation or impairment. Based on the available information, the pilot likely did not maintain airplane control during the intentional power-on stall, which resulted in an inadvertent spin at an altitude from which he was unable to recover.

The pilot’s flight logbook was not located. The airplane operator provided the pilot’s flight history from their reservation and billing system. Based on the available documentation, the pilot began flight training on August 22, 2023. The pilot had a total flight experience of 62.1 hours, of which 8.8 hours were flown as pilot-in-command (solo). The pilot had flown 59.4 hours in a Cessna 172C and 2.7 hours in a Cessna 150L. On May 6, 2024, the pilot received a solo flight endorsement for Cessna 172 and Cessna 150 airplanes from his flight instructor. Recent Maintenance According to maintenance documentation, the last annual inspection of the airplane was completed on July 25, 2023, at 3,025.8 total airframe hours and 1,959.0 hours since the last engine overhaul. A 50-hour inspection was completed on April 9, 2024, at 3,073.6 hours total airframe time. The last logged maintenance was to replace the right fuel sender unit gasket, which was also completed on April 9, 2024, at 3,075.8 hours total airframe time. A review of the airplane maintenance logbooks and a summary of recent pilot-reported discrepancies did not reveal any unresolved maintenance issues. According to the airplane operator’s dispatch system documentation, the airplane’s recording tachometer indicated 3,085.5 hours at the beginning of the accident flight. The airplane’s recording tachometer was destroyed by the postimpact fire, which prevented calculation of the airplane’s airframe and engine times at the time of the accident. Weight and Balance The airplane’s empty and maximum takeoff weights were 1,135.5 lbs and 1,600 lbs, respectively. The airplane’s useful load was 464.5 lbs. The gross weight and center-of-gravity location at engine startup were calculated based on the reported pilot weight of 155 lbs, estimated 10 lbs of baggage, a full fuel load of 22.5 gallons (135 lbs), and 6 quarts of engine oil (11 lbs). The gross weight at engine startup was 1,446.5 lbs. center-of-gravity location was 34.6 inches aft datum, and the moment was 50,100 lbs-inches. Based on the Cessna 150L Owner’s Manual, the airplane was within weight-and-balance limits at engine startup and at the time of the accident. Aerodynamic Stall Speed According to the Cessna 150L Owner’s Manual, the wings-level aerodynamic stall speed at maximum gross weight (1,600 lbs) with the flaps retracted (0°) is 55 mph. The aerodynamic stall speed decreases to 48 mph with the flaps fully extended (40°). The wings-level aerodynamic stall speed is reduced by the square root of the weight ratio when the airplane is operated at a weight less than the maximum gross weight. The Tarrant County Medical Examiner's Office performed the pilot’s autopsy. According to the pilot’s autopsy report, his cause of death was blunt force injuries with smoke inhalation and thermal injuries. The manner of death was accident. FAA Forensic Sciences Laboratory toxicological testing of postmortem specimens from the pilot did not detect any carboxyhemoglobin, ethanol, or tested-for drugs. Glucose was detected at 62 mg/dL in vitreous but was not detected in urine. On May 15, 2024, about 2039 central daylight time, a Cessna 150L airplane, N1701Q, was destroyed during an accident near Godley, Texas. The student pilot was fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 solo instructional flight. According to available ADS-B track data, at 1948:44, the airplane was in a climb after takeoff from runway 15 at Cleburne Regional Airport (CPT), Cleburne, Texas. The airplane entered a right traffic pattern for runway 15, completed one landing, and then flew south-southeast of CPT, as shown in figure 1. At 1959:10, the airplane turned west and flew over Lake Pat Cleburne before it turned south-southwest. Between 2001:55 and 2004:40, about 5 nautical miles (nm) south-southwest of CPT, the airplane completed a series of left and right 360° turns between 3,200 and 3,300 ft mean sea level (msl) before it continued south-southwest. At 2007:30, the airplane turned west-northwest and continued climbing to a maximum altitude of about 4,100 ft msl. At 2011:40, the airplane entered a descent from 4,100 ft msl while it continued west-northwest. At 2014:04, the airplane leveled off at 3,300 ft msl. At 2015:01, the airplane entered a climb while it continued west-northwest. At 2017:00, the airplane turned west as it climbed to about 4,000 ft msl. Between 2018:25 and 2022:15, about 4 nm south-southeast of Granbury, Texas, the airplane completed a series of descending left and right turns. After the turns, the airplane continued to descend as it flew east-northeast toward the Brazos River near DeCordova, Texas. Figure 1. Plot of airplane flight track data. Between 2025:50 and 2028:56, about 1.25 nm south-southwest of DeCordova, Texas, the airplane completed a series of descending left-and-right turns over the Brazos River near the west side of Lake Granbury. During the turns, the airplane descended to about 2,300 ft msl before it entered a climb. After the turns, the airplane continued east over Lake Granbury and climbed to about 2,600 ft msl. After it flew over the eastern side of Lake Granbury, the airplane continued east-southeast back toward CPT. During the final 10 minutes of the flight, there were two prolonged periods without recorded FAA ADS-B track data. However, an internet-based flight tracking website, FlightAware.com, continued to track the airplane without similar data dropouts and was used as the primary source of track information for the remainder of the flight. Airplane performance calculations based on the available track data revealed that, between 2033:15 and 2038:00, the airplane completed four large deceleration-and-acceleration cycles, as shown in figure 2. During each of these four cycles, the airplane’s calibrated airspeed (CAS) decreased below aerodynamic stall speed before it increased again. The airspeed and altitude profiles during these maneuvers were consistent with the pilot practicing aerodynamic stalls. At 2037:30, during the fourth deceleration-and-acceleration cycle, the airplane decelerated to about 31 mph CAS before it began accelerating. Over the next 10 seconds, the airplane briefly leveled off at 1,865 ft msl before it entered a climb. At 2038:25, the airplane had accelerated to 91 mph CAS and was climbing through 1,940 ft msl at a vertical speed about 100 ft per minute (fpm). Between 2038:25 and 2039:20, the airplane began decelerating as the vertical speed increased from 100 fpm to 800 fpm before returning to near zero. Between 2039:21 and 2039:26, the airplane’s vertical speed increased from near zero to about 1,085 fpm. Between 2039:26 and 2039:30, the airplane transitioned from a climb to a descent as it decelerated to about 33 mph CAS. At 2039:30, the FlightAware track data coverage ended with the airplane descending through 2,400 ft msl at a vertical speed about -600 fpm. Between 2039:31 and 2039:37, there was no ADS-B track data available. At 2039:37, FAA ADS-B track data coverage resumed, with the airplane descending through 1,700 ft msl at a vertical speed about -10,000 fpm. At 2039:44, the FAA ADS-B track data ended with the airplane descending through 1,140 ft msl (about 216 ft above ground level) at a vertical speed about -7,200 fpm. A witness and her daughter were driving in their truck about 0.5 mile north-northwest of the accident site when they saw the airplane flying lower than what the witness thought was normal. They could not hear the airplane because they were inside their truck at the time, but they saw the airplane flying at slow speed, almost “hovering” in the air, before it suddenly entered a spiraling nosedive. The airplane completed at least 6 to 8 rotations in the descending spiral before it descended out of sight behind a hill. They subsequently called 911 to report t