Air Tractor Inc AT-602 N4257R accident near Penrose, Arkansas

Probable cause

The loss of partial engine power due to a fatigue crack in the engine's fuel control bellows.

NTSB analysis

While approximately 75 feet above the ground, the airplane experienced a partial loss of engine power. Unable to maintain altitude, the pilot performed a forced landing to a wet rice field. During the landing, the airplane impacted a dirt mound, nosed over, and came to rest inverted. During the postaccident engine examination, the fuel control unit was removed and a functional test of the unit performed. The test revealed that the fuel unit's evacuated bellows had developed a fatigue crack in the outer ply surface. This crack would have resulted in a reduced fuel flow to the engine and a subsequent loss of engine power. Laboratory analysis concluded that the crack had originated in an area of several corrosion pits. The cause of the corrosion could not be determined.

Text from the NTSB. Open the NTSB docket for CEN10LA353 for the full record.