Air Tractor AT-301 N8564S accident near Winner, South Dakota

Probable cause

The pilot's improper decision to attempt a takeoff with a tailwind and his failure to achieve the proper airspeed for liftoff, which resulted in the airplane exceeding its critical angle of attack and entering an aerodynamic stall shortly after liftoff.

NTSB analysis

The commercial pilot was conducting a local agricultural application flight. The pilot reported that shortly after liftoff from runway 31, at an altitude of 3-5 ft above the runway, he heard a loud bang and the airplane began to yaw left. The airplane descended and bounced off the left side of the runway. The pilot stated that he increased the airplane's pitch to gain altitude, but the airplane encountered an aerodynamic stall and the left wing dropped. As he attempted to dump the load of insecticide, the airplane nosed over into the ground and came to rest inverted. The airplane sustained substantial damage to the fuselage, both wings, and the empennage. A postaccident examination revealed no evidence of a mechanical malfunction or failure that would have precluded normal operation during the flight. The engine, which separated from the airframe during impact, exhibited impact-related damage and no mechanical malfunctions.

The surface wind at the time of the accident would have resulted in an 8-knot tailwind during the takeoff. The effect of the tailwind would have resulted in a greater groundspeed and additional runway length needed to attain the proper liftoff airspeed. The pilot likely conducted a premature liftoff at an inadequate airspeed, which resulted in the airplane exceeding its critical angle of attack and entering an aerodynamic stall.

Text from the NTSB. Open the NTSB docket for CEN14LA284 for the full record.