Air Tractor Inc AT 502B N502LH accident near Virden, Illinois

Probable cause

The pilot’s failure to establish a proper airspeed during takeoff with the airplane near its maximum gross weight and with a quartering tailwind.

NTSB analysis

The pilot reported that the airplane had just been loaded and that he was beginning his sixth agricultural application flight of the day. He noted that, during the previous flights, the wind was from the southwest-southeast and less than 5 knots. Before departing on the sixth flight, he checked the wind sock, which indicated that the wind was from the southwest. He also checked his handheld GPS, which indicated that the local area wind was mainly from the west at 3 to 5 knots. The pilot started the takeoff roll on the runway heading west and noted that, three-quarters of the way down the runway, the airspeed had not yet reached takeoff speed. He jettisoned some of the load so that the airplane could clear the corn at the end of the runway. When the airplane cleared the corn, the pilot ceased the jettison. However, the airplane then began to descend, so the pilot jettisoned more of the load. The airplane continued to descend, banked hard left, and impacted the ground.

The pilot reported that there were no mechanical malfunctions with the airplane that would have precluded normal operation. The airplane was only about 30 lbs below its maximum gross weight. Witnesses stated that, immediately after the accident, the wind was from the southeast about 6 knots, which would have resulted in a quartering tailwind during the takeoff. It is likely that the combined effects of the airplane's near maximum gross weight and the quartering tailwind degraded the airplane's climb performance during takeoff.

Text from the NTSB. Open the NTSB docket for CEN15LA335 for the full record.