N10140

On August 9, 2001, at 0900 central daylight time, an Air Tractor AT-401 agricultural airplane, N10140, was substantially damaged during a forced landing following a loss of engine power while maneuvering near Grand Coteau, Louisiana. The airplane was registered to Worthy Flying Service, Inc., of Gore Springs, Mississippi, and operated by Aerial Crop Care, Inc., of Port Barre, Louisiana. The commercial pilot, sole occupant, was not injured. Visual meteorological conditions prevailed, and a flight plan was not filed for the 14 Code of Federal Regulations Part 137 aerial application flight. The local flight originated from a private strip near Arnaudville, Louisiana, at 0845.

According to the pilot, the airplane had completed a spray pass from south to north, and during a turn around maneuver, the "#4 jug blew." The pilot emptied the airplane's load and initiated a forced landing to a dirt road; however, the aircraft was unable to land on the road. The airplane touched down in a sweet potato field perpendicular to the rows with its right wing first. Subsequently, as the airplane touched down, its main landing gear collapsed. The airplane came to rest upright.

Examination of the airplane by the FAA inspector, who responded to the accident site, revealed that the right main landing gear was separated, and the left main landing gear was folded aft. The fuselage at the right wing attach point was buckled, and the right wing tip was damaged. An examination of the engine revealed that the #4 cylinder head had fractured at the exhaust valve rocker arm boss.

A review of the maintenance records revealed that on August 4, 2001 (4.4 hours prior to the accident), the Pratt & Whitney R-1340-AN-1 engine's cylinder heads were inspected for cracking in accordance with Airworthiness Directive 99-11-02. No cylinder head cracking was noted.