Piper PA-18-150 N3471Z accident near Okaton, South Dakota

Probable cause

The pilot's failure to perform an adequate preflight inspection of the airplane and obstruction of the aileron control system by snow and ice, which led to a loss of control during flight.

NTSB analysis

The pilot reported that 2 days before the accident, snow accumulated on the airplane’s wings while it was parked in an open front hangar. The day before the accident, the temperature was warmer, and the pilot believed that the snow melted and ran rearward to the aileron gap/hinge locations, re-freezing during the nighttime hours. On the day of the accident, the pilot was in a hurry to use the airplane to check his pastures and brushed the snow off of the wings but did not perform a thorough preflight check of the airplane, including checking freedom of movement of the ailerons. After takeoff, the airplane began turning to the left. The pilot attempted to correct the turn, but the airplane did not respond. When he looked out at the wings, he could see that the ailerons were not responding to control inputs as they should. As he was attempting to regain control, the airplane descended into trees, resulting in substantial damage to both wings, the fuselage, and tail surfaces. A postaccident examination of the airplane revealed no mechanical defects that were determined to have existed before the accident.

Text from the NTSB. Open the NTSB docket for CEN13CA108 for the full record.