Air Tractor AT-400 N3159B accident near Balko, Oklahoma

Probable cause

The pilot's failure maintain clearance from a meteorological tower while en route at a low altitude. Contributing to the accident was the sun's glare.

NTSB analysis

The commercial pilot was en route from a private airstrip to a nearby field to apply herbicide and flying about 150 feet agl, when the airplane struck a 197-foot meteorological tower (MET) about 35 feet from its top. A survey of the accident scene revealed that the sun was ahead of and to the right of the airplane's flight path and likely obstructed the pilot's ability to see the tower. An examination of the airplane did not reveal any preimpact anomalies.

The NTSB recently concluded that, due to their rapid construction and lack of conspicuity, METs pose a threat to pilots who conduct low-altitude operations and recommended required registration, marking, and—where feasible—lighting of these structures in order to aid pilots in avoiding them.

Text from the NTSB. Open the NTSB docket for CEN13FA465 for the full record.