Air Tractor Inc AT-502B N634LA accident near Hickory Ridge, Arkansas

Probable cause

The pilot's failure to maintain clearance from a transmission line while maneuvering at low altitude.

NTSB analysis

During an aerial application flight, the airplane collided with a transmission line during a turn. The line became entangled with the airplane, and the airplane collided with terrain. Examination of the airplane did not reveal any preimpact anomalies that would have precluded normal operation of the airplane.

The pilot's medical certificate had expired several months before the accident. The pilot had been diagnosed with depression, diabetes mellitus, diabetes insipidus, hypogonadism, hypothyroidism, and hypoadrenalism; however, he had not reported any of these conditions or the medications used to treat them to the FAA. It is unlikely that the pilot's diabetes insipidus, hypogonadism, hypothyroidism, or hypoadrenalism or their treatments contributed to the accident. However, his poorly controlled diabetes mellitus could have led to high blood sugar, which can result in blurred vision, or low blood sugar, which can slow psychomotor functioning Additionally, the pilot was known to have peripheral neuropathy with decreased sensation in his feet and a foot drop, which could have impaired his physical ability to use the rudder pedals. It could not be determined if the pilot's diabetes mellitus contributed to the accident. Further, the status of the pilot's psychiatric disease, including the severity of symptoms from his depression and any other psychiatric symptoms, around the time of the accident is unknown. Therefore, whether the pilot's psychiatric disease contributed to the accident could not be determined.

Text from the NTSB. Open the NTSB docket for CEN16LA312 for the full record.