Air Tractor Inc AT-602 N602WR accident near Oxford, Indiana

Probable cause

The pilot’s exceedance of the airplane’s critical angle of attack and failure to maintain adequate airspeed while maneuvering during an agricultural flight, which resulted in an aerodynamic stall and a loss of control at too low of an altitude to recover. Contributing to the accident was the pilot’s excessive flap extension during the turn.

NTSB analysis

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.

Text from the NTSB. Open the NTSB docket for CEN24FA278 for the full record.