Accident Overview
On June 10, 2014, about 2041 central daylight time, an Air Tractor AT-301 airplane, registration N8564S, operated by Semper Fi Aviation, LLC, was substantially damaged when it impacted terrain shortly after takeoff at Winner Regional Airport (ICR), Winner, South Dakota. The commercial pilot was not injured. The flight was conducted under Title 14 Code of Federal Regulations Part 137 as a local agricultural application flight without a flight plan. Day visual meteorological conditions prevailed.
Pilot Report
According to the pilot, the airplane weighed about 5,000 lbs after loading with 200 gallons of insecticide and 90 gallons of fuel. No anomalies with the engine or wheel brakes were noted during taxi and before takeoff runup. The takeoff was made on runway 31 (4,500 ft by 75 ft, concrete), and liftoff was achieved with about half of the runway remaining. Shortly after liftoff, at an altitude of 3-5 ft above the runway, the pilot 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 increased pitch to gain altitude, but the airplane entered an aerodynamic stall and the left wing dropped. As he attempted to dump the insecticide load, the airplane nosed over and impacted the ground alongside the runway. The airplane came to rest inverted, and the pilot exited uninjured through the left-side window.
Postaccident Examination
A Federal Aviation Administration (FAA) airworthiness inspector conducted an examination. Runway surface evidence included a tire skid mark consistent with a main landing gear tread width, beginning about 1,000 ft from the departure end of runway 31. The wavy marking continued about 30 ft until it departed the left runway edge. A second skid mark, about 10 ft right of the first, began about 10 ft from the left edge. The airplane exited the left runway edge about 970 ft from the end and entered a grass field. At least 12 propeller strike marks were observed between the departure point and the main wreckage, which was located about 100 ft left of the runway edge and about 750 ft from the end of runway 31. The airplane was inverted, facing back toward the runway on a southeast heading. Propeller strike marks and oil-covered grass preceded the main wreckage.
The airplane sustained substantial damage to the fuselage, both wings, and empennage. The aft fuselage was crumpled forward of the horizontal stabilizer. The empennage remained attached; the vertical stabilizer and rudder were crushed. Flight control continuity was confirmed. The left landing gear leg had separated from the fuselage with overstress signatures on attachment fittings. The engine had separated from the airframe and was found under the left wing. The propeller remained attached. Engine examination revealed impact-related damage but no mechanical malfunctions. Specifically, the No. 5 exhaust valve body was fractured with a deformed valve cover and bent studs, consistent with impact damage. Overall, no evidence of a mechanical malfunction or failure was found.
Weather Information
At 2053, about 12 minutes after the accident, the ICR weather observing system reported wind from 130° at 8 knots, 10 miles surface visibility, clear skies, temperature 21°C, dew point 13°C, and altimeter setting 29.77 inHg. Recorded wind data showed a southeasterly wind of 8-13 knots during the three hours before and the hour after the accident. The surface wind at the time of the accident, from 130° at 8 knots, resulted in a direct tailwind during takeoff. In his accident report, the pilot reported the surface wind as 130° at 2 knots.