CEN24FA278

The pilot was conducting an aerial application flight when the accident occurred. The airplane’s GPS data indicated that the pilot was in the process of completing a trim pass at the south edge of the target field. Flight track data showed that the airplane entered a climbing left turn, likely to complete a trim pass on the north side of the field. The final data point recorded the airplane about 0.1 nm from the accident site. The airplane impacted the field inverted and in a nose-low attitude with no forward momentum, consistent with an aerodynamic stall/spin, which resulted in the airplane rolling inverted. Examination of the airplane did not reveal any preimpact mechanical malfunctions or anomalies that would have precluded normal operation. The flaps were found fully extended. The engine exhibited signatures consistent with producing power during impact. The propeller blades exhibited compound bend and twist progression from forward to aft in the sequence of rotation consistent with producing thrust at impact. The pilot’s cardiovascular disease increased his risk of experiencing a sudden impairing or incapacitating cardiac event, such as arrhythmia, chest pain, or heart attack. The autopsy report summary does not provide specific evidence that such an event occurred; however, such an event does not leave reliable autopsy evidence if it occurs shortly before death. Based on the available information, the pilot likely exceeded the airplane’s critical angle of attack during a steep turn with full flaps; the airplane then entered an aerodynamic stall at an altitude too low for recovery. The pilot’s decision to enter the steep turn with full flaps increased the likelihood of an aerodynamic stall.

A review of the airplane’s maintenance records showed no outstanding maintenance discrepancies. The Air Tractor AT-602 airplane flight manual (AFM) stated in part: “Flaps may be used as a turning aid providing small deflections are used (5 to 8 degrees). The usual method of using flaps is to make the pull-up and initial bank with flaps retracted. As the aircraft is being banked to turn back into the field, touch the flap switch briefly and let off a little back pressure on the stick, as the flaps cause a slight pitch up tendency. Continue the turn, and as you line up for your pass, retract the flaps.” On July 22, 2024, about 1830 eastern daylight time, an Air Tractor AT-602 airplane, N602WR, was substantially damaged when it was involved in an accident near Oxford, Indiana. The pilot was fatally injured. The flight was conducted under 14 Code of Federal Regulations Part 137 as an aerial application flight. According to the airplane owner and operator, the pilot was spraying two fields near the accident site. The airplane departed with full fuel tanks, and the hopper was loaded with liquid applicant. Onboard GPS data revealed that the airplane departed the operator’s private runway about 1741 and proceeded north. The pilot sprayed two fields beginning about 1752. Immediately before the accident, the pilot was completing a west-to-east trim pass on the south side of the northern field. The recorded GPS data ended near the end of the trim pass. The accident site was located in a soybean field about ½ nautical mile (nm) east of the field being sprayed. Figure 1 shows the airplane’s flight track and the target fields in green. The yellow arrows indicate the direction of the final trim pass, and the yellow circle indicates the final recorded data point. Other flight track data indicated that, after the trim pass, the airplane made a climbing left turn toward the accident site. The final recorded point was about 0.1 nm to the southwest of the accident site. Figure 1. The accident flight track overlaid on Google Earth. The yellow arrows indicate the final portion of the flight, which included a trim pass at the south end of the target field. An autopsy of the pilot was performed by a forensic pathologist for the Benton County Coroner, Fowler, Indiana, which listed the cause of death as multiple injuries and the manner of death as accident. The pilot’s autopsy identified coronary artery disease, with an area of 75% narrowing of the proximal left anterior descending coronary artery by plaque. The heart was described as enlarged, with right ventricular dilatation and mild left ventricular hypertrophy. Toxicology testing performed at the FAA Forensic Sciences Laboratory found no drugs of abuse. The pilot’s personal logbooks were not received during the course of the investigation. The airplane impacted inverted in a nose-down attitude and came to rest oriented on 137° heading. A small postimpact fire ensued, which was extinguished by first responders. Thefire damage was limited to the aft portion of the engine compartment. All components of the airplane were located in the immediate vicinity of the accident site and there was no debris field nor any disturbance in the crop leading to the main wreckage. The top of the fuselage, vertical stabilizer, rudder, both wing leading edges, and the upper wing skins were crushed downward relative to the airframe, which was in an upright position. The flight controls were traced from the cockpit to the flight control surfaces through impact damage and overload separations. The flap actuator was found intact and was extended to a position that correlated to full flap extension of 28°. The engine remained attached to the engine mount, with significant engine mount damage and segmentation. The left-side exhaust duct exhibited torsional buckling consistent with torque production. The right-side exhaust duct was slightly buckled. The propeller assembly was partially embedded in the ground with two propeller blades visible while the other three blades were buried in the ground. The propeller remained attached to the propeller flange and reduction gearbox, and the blades remained attached to the hub. The blades exhibited compound bend and twist progression from forward to aft in the sequence of rotation, consistent with producing thrust during impact. Postaccident examination of the airplane did not reveal any preimpact mechanical malfunctions or failures that would have precluded normal operation. The airplane’s SATLOC GPS was downloaded by installing the unit into another company airplane. The unit recorded the accident flight and indicated when the airplane’s spray function was being used. The engine’s full flight data acquisition, storage, and transmission (FAST) box was recovered and the data was downloaded by Pratt & Whitney Canada. The data revealed that the unit’s memory was completely full and had not recorded new data since September 2019; therefore, no accident flight data was recovered.