Air Tractor Inc AT 502 N700LA accident near Portales, New Mexico

Probable cause

The pilot's decision to fly the airplane under transmission lines while maneuvering at low altitude in high-density altitude conditions, which resulted in subsequent collision with terrain.

NTSB analysis

The pilot reported that, during an agricultural application flight and while maneuvering at the destination field in a left turn, he realized that the airplane was not going to be able to climb over transmission lines in his flightpath. He added that he lowered the nose to fly under the transmission lines, but the "airspeed was still too low," and the airplane impacted an embankment, slid across the ground for about 100 ft, and nosed over.

The airplane was destroyed by the impact and a postcrash fire.

The pilot reported that there were no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation.

An automated weather observation station 10 nautical miles north of the accident reported, about 5 minutes before the accident, calm wind, temperature 102°F (39°C), dewpoint 43°F (6°C), and barometric setting of 29.77 inches of mercury. The calculated density altitude was 8,200 ft.

According to the Federal Aviation Administration Koch Chart, considering the surrounding temperature and field elevation, the airplane would have likely experienced a 65% decrease in the normal climb rate.

Text from the NTSB. Open the NTSB docket for GAA17CA360 for the full record.