Rockwell International S2R N4956X accident near Strasburg, North Dakota

Probable cause

The pilot’s intentional flight under power lines and his failure to maintain clearance from the lines during an aerial application flight.

NTSB analysis

The pilot had completed one aerial application flight and was in the process of spraying a sunflower field. The flight track indicated that the airplane entered the area from the north and made a left turn over the field. The recorded flight track ended before the airplane descended toward the target field. It is likely that the pilot started spraying the field beginning at the northeast corner and headed west. A witness driving eastbound observed the airplane flying west after it exited the sunflower field. As the airplane flew under three power lines, the top of the vertical stabilizer hit the second line. The airplane then collided with the third line, crashed onto a road, and slid into a field.

A colleague of the pilot, who was familiar with the operation, stated that he and the pilot had sprayed this field many times before and that they always used a north-south racetrack pattern. He had never seen the pilot spray this field in an east-west pattern before and added that it should not be done due to the large powerlines on the west side of the field.

A postaccident examination of the accident site and airplane revealed wire strike signatures on the airplane. Two areas on the airplane exhibited black sooting and burn marks, which were indicative of the airplane contacting two power lines simultaneously resulting in electrical arcing. The airplane examination did not reveal any evidence of preimpact mechanical malfunction or anomalies that would have precluded normal operation.

Text from the NTSB. Open the NTSB docket for CEN21FA368 for the full record.