Air Tractor Inc AT 602 N4196Y accident near Stirum, North Dakota

Probable cause

The pilot's decision to attempt flight with low-level fog in the area, which resulted in an encounter with instrument meteorological conditions and impact with terrain.

NTSB analysis

An employee of the operator reported that the planned aerial application flight was delayed about 2 hours while the pilot waited for the weather conditions to improve. The pilot had spoken with individuals by phone before the flight in an attempt to assess the local conditions. The visibility at the airport was about 1-1/2 miles when the pilot departed.

A witness reported that she was sitting on her patio when she heard the airplane. The sound of the engine was normal, "not anything unusual at all." She observed the airplane emerge from the fog and "within seconds" impact the ground. The airplane was level or descending slightly and did not appear to change its flight path before impacting gradually rising terrain. She noted that the airplane did not appear to be out of control, nor did it seem that anything was wrong mechanically. She recalled that it was "very, very foggy" at the time, with about 200 yards visibility. There was no precipitation and little or no wind at the time.

A postaccident examination did not reveal any anomalies consistent with a preimpact failure or malfunction.

It is likely that the pilot encountered instrument meteorological conditions while operating at a low level and inadvertently impacted the terrain.

Text from the NTSB. Open the NTSB docket for CEN17LA244 for the full record.