What happened
The pilot of an aerial application airplane initiated rotation at a speed between 60 and 65 mph. Following rotation, the aircraft accelerated to 85 mph while in the climb phase. During this ascent, the pilot retracted one notch of flaps, at which point the aircraft ceased its climb.
A rapid descent followed the flap retraction. Despite the throttle and propeller controls being set to full power, the airspeed decelerated to 60 mph during the descent. This high rate of descent continued until the aircraft collided with the ground, resulting in no injuries to the pilot.
The investigation
An on-scene investigation was conducted to determine if mechanical issues contributed to the accident. Investigators found no pre-impact mechanical anomalies regarding the engine or the airframe. Additionally, a review of the pilot's operating handbook indicated that the required liftoff speed for the aircraft is 65 mph.