What happened
While performing a racetrack pattern spray run, an agricultural aircraft experienced a sudden and rapid pitch-down during a turn. The aircraft was approximately three-quarters of the way through the maneuver when it collided with the ground. The pilot was unable to recall the specifics of this final turn or explain why the aircraft's flight path deviated from the previous patterns.
The investigation
Investigators analyzed the limited available flight data and noted that the final turn was executed with a tighter radius than the preceding turns in the pattern. While this pattern of flight could suggest the occurrence of an aerodynamic stall, the available data was insufficient to confirm this specific phenomenon.
An examination of the aircraft's maintenance records showed no mechanical defects were reported during the previous flight or leading up to the point the pilot could remember. Furthermore, a post-accident inspection conducted by the operator failed to identify any mechanical issues with VH-WHR. Due to the lack of recoverable data, the exact reason for the aircraft's descent could not be established.
Findings
- The aircraft VH-WHR pitched down and struck the ground for reasons that could not be determined.
- The pilot was wearing a personal flight helmet during the accident.
- The left side of the helmet impacted the interior of the cockpit.
- The impact with the helmet likely prevented more serious head injuries to the pilot.