What happened
While flying at an altitude of approximately 150 to 200 feet, the pilot performed an aileron input significant enough to cause fluid in the hopper tank to slosh. Following this input, the aircraft began to shudder as if experiencing a stall. The pilot attempted to increase airspeed by moving the control stick forward, but the shuddering persisted and the airplane began a left turn.
In an attempt to correct the flight path, the pilot applied right aileron and rudder. A visual inspection of the ailerons revealed that both were in the up position. Upon reducing power, the left wing dropped. The pilot subsequently increased power and applied rudder to maintain control, but the aircraft continued in a slight left turn. During the execution of a forced landing in an open field, the pilot reduced power once more; at this time, the left wing dropped and collided with the ground. There were no injuries reported.
The investigation
An examination of the aircraft revealed that the left aileron control rod end fitting had become disconnected at the adjustment jam nut. The investigation determined that the rod end had lost its necessary flexibility due to rust and corrosion, resulting from a lack of proper attention or lubrication.