19990624007539A

Acft crashed into a field during aerial application, other circumstances are unknown. (.19) on June 24, 1999, at 0730 central daylight time, an air tractor AT-301, N3159M, piloted by a commercial pilot, received substantial damage on impact with terrain near Veblin, south dakota. Visual meteorological conditions prevailed at the time of the accident. The 14 CFR 137 flight was not on a flight plan. The pilot sustained minor injuries. The flight originated from britton municipal airport, britton, south dakota at approximately 0700. The pilot stated that he loaded the air tractor with 240 gallons of a mixture for aerial application on leafy spurge. He said that the fuel tanks were half full. Winds were out of the southwest at 6 to 10 knots. He said he was spraying in some local hills. He stated he completed three passes. On his fourth, he said that he was climbing above the tree line and encountered "bad air". He had applied full power but lost lift once over the tree line. The airplane settled and contacted the ground in a southerly direction. The engine was torn off the fuselage, along with the landing gear and tail wheel. The pilot stated that the fuselage came to res t on a southeasterly direction. (-23)the pilot was making a southbound spray pass up an extreme uphill terrain. The aircraft did not have enough airspeed and impacted the ground, cartwheeled around 180 degrees and came to rest. Site investigation revealed major damage to the forward fuselage, right wing and landing gear. The chemical load was not dumped.