What happened
On the morning of the accident, a Cessna 188 Agwagon was returning to a private airstrip located two miles south of Marengo, Saskatchewan. The pilot had been performing aerial herbicide applications on a cereal crop. During the flight, which was conducted under visual flight rules, the aircraft failed to arrive at its destination. A subsequent search led investigators to a field approximately one mile southwest of the airstrip.
The aircraft struck the ground while in a descending turn, maintaining a 40-degree nose-down and 15-degree right-wing-low attitude. The impact occurred at a speed consistent with normal cruising range. The aircraft was destroyed, and the pilot sustained one fatality.
The investigation
Investigators examined the aircraft's mechanical condition and the pilot's recent history. The engine and propeller were found to be producing normal power at the time of impact, and no malfunctions in the aircraft's systems were identified. While the aileron and flap cables had failed, this was determined to be a result of the impact forces rather than a cause of the crash.
The investigation also reviewed the pilot's medical and professional status. The pilot was a certified commercial pilot with 578 total flying hours. Medical examinations and toxicology reports were conducted; while no specific chemicals or solvents were detected in the pilot's system, the volatility of such substances meant their presence could not be entirely ruled out. Additionally, the pilot had experienced an episode of vertigo three days prior to the accident.
Findings
- The pilot likely experienced a level of incapacitation that led to the aircraft entering a descending turn and striking the terrain.
- A possible cause of this incapacitation was an inner ear disorder, as the pilot had recently suffered from symptoms of vertigo.
- The pilot's heavy workload, involving both flying and business management duties, may have resulted in fatigue.
- The potential effects of agricultural chemical exposure were considered a contributing factor.