NTSB Identification: MIA88LA147.
The docket is stored on NTSB microfiche number 36112.
Accident occurred Thursday, April 14, 1988 in HASTINGS, FL
Probable Cause Approval Date: 03/13/1989
Aircraft: AIR TRACTOR AT-301, registration: N8841S
Injuries: 1 Minor.

NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.

WHILE ON AN AERIAL APPLICATION FLT SHORTLY AFTER TAKEOFF, THE ENG LOST POWER. THE PLT THEN DUMPED THE LOAD OF FERTILIZER & LANDED THE ACFT IN A FIELD. AFTER TOUCHDOWN IT NOSED OVER & CAME TO REST. EXAMINATION OF THE ENG REVEALED THAT THE NO. FOUR CYLINDER EXHAUST VALVE ROCKER ARM SUPPORT FAILED PREVENTING THE VALVE FROM OPENING. AS A RESULT OF THE EXCESS PRESSURE INSIDE THE CYLINDER WHEN THE INTAKE VALVE OPENED. THE EXHAUST WAS FORCED THROUGH THE INTAKE SYSTEM RESULTING IN ENG BACKFIRING.

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

ENGINE ASSEMBLY,ROCKER ARM/TAPPET..FAILURE,TOTAL

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

ENGINE ASSEMBLY,VALVE,EXHAUST..DISABLED


Contributing Factors

TERRAIN CONDITION..SOFT


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