Casualties unknown

1998-08-22: Air Tractor 401 (N10103) — Holly Bluff, MS

Holly Bluff, MS, US

On August 22, 1998, an Air Tractor 401 (registration N10103) was involved in an aviation accident near Holly Bluff, MS. Investigators recorded the probable cause as: The loss of engine power was caused by the failure to maintain fuel pressure in the pressure carburetor, likely due to a defective needle assembly. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 1781061362Data APIEditorial standards

An aircraft experienced a sudden loss of engine power and black exhaust smoke while climbing out from a field, forcing an emergency landing.

What happened

The pilot had been flying for approximately forty-five minutes on the current fuel load and estimated having more than one hour of fuel remaining at the time of the incident. While performing the first swath run during a climb out from a field, the engine lost power. The pilot observed black smoke emitting from the exhaust as the power loss occurred. Due to the circumstances, the only available area for an emergency landing was directly ahead.

The investigation

During the post-accident examination of the engine assembly, investigators were able to start the engine; however, it ran roughly and produced black smoke. Further technical examination revealed that the fuel pressure provided by the engine-driven fuel pump was not being maintained within the pressure carburetor. A local mechanic assisting with the examination noted that a loss of fuel pressure in this type of carburetor is typically associated with a defective needle assembly.

Maintenance records indicated that the engine assembly had accumulated 1,150 hours of service since its last overhaul, which is near the recommended 1,200-hour interval. Additionally, the records did not indicate whether the carburetor itself had been overhauled since the most recent engine overhaul.

Probable cause

The loss of engine power was caused by the failure to maintain fuel pressure in the pressure carburetor, likely due to a defective needle assembly.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001211X10772. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.