FTW03LA136

During the short field takeoff, the airplane accelerated down the dirt runway and became airborne in ground effect. Passing off the end of the runway, the pilot stated he "could tell that the wheels were [dragging] in the wheat" and thought the airplane could "fly out of it in ground effect." The pilot attempted to dump the chemical load, but pulled the spray handle instead of the emergency hopper dump lever. Subsequently, the right wingtip contacted the ground, the airplane cartwheeled and came to rest inverted. The density altitude was calculated as 1728 feet based on the outside air temperature of 20 degrees Celsius, a dew point of 16 degrees Celsius, and an altimeter setting of 29.91 inches of mercury.

On April 18, 2003, at 1730 central daylight time, an Air Tractor AT-301 agricultural airplane, N36531, owned and operated by Ag Aerial Service, LLC., of Batchelor, Louisiana, was substantially damaged when it impacted the ground following a loss of control during takeoff from a private dirt airstrip near Batchelor, Louisiana. The commercial pilot, who was the sole occupant, was not injured. Visual meteorological conditions prevailed, and a flight plan was not filed for the Title 14 Code of the Federal Regulations Part 137 aerial application flight. The local flight was originating at the time of the accident.

The 7,634-hour pilot reported in the Pilot/Operator Aircraft Accident Report (NTSB Form 6120.1/2), that at takeoff, the airplane contained 225 gallons of water and 60 gallons of fuel. The airplane's maximum hopper capacity was 350 gallons, and maximum fuel tank capacity was 80 gallons. A 10-degree flap setting was used for the short field takeoff from the 2,000-foot dirt runway that was adjacent to a wheat field.

The pilot stated that he brought the engine power to 36 of inches manifold pressure for takeoff. As the tail of the airplane lifted, the pilot pulled back on the control stick and "could tell the airplane was not ready to fly but became airborne." As the airplane passed over the end of the runway, the pilot "could tell that the wheels were [dragging] in the wheat" and thought the airplane could "fly out of it in ground effect."

The pilot attempted to dump the chemical load; however, he inadvertently pulled the spray handle instead of the emergency hopper dump lever. Subsequently, the right wingtip contacted the ground and the airplane cart wheeled coming to rest in the inverted position. The pilot further stated that he had dumped the chemical load before and "just grabbed the wrong handle this time."

The FAA inspector reported the empennage, aft of the cockpit and the right wing spar, were bent.

Based on the outside air temperature of 20 degrees Celsius, a dew point of 16 degrees Celsius, and an altimeter setting of 29.91 inches of mercury, the NTSB investigator-in-charge determined the density altitude was 1,728 feet.