Casualties unknown

Uncontained Left Engine Failure During Takeoff Due to Fatigue Fracture (N986US)

Memphis, TN, US

On May 5, 1994, a Douglas DC-9-32 (registration N986US) operated by Northwest Airlines, Inc was involved in an aviation accident near Memphis, TN. Investigators recorded the probable cause as: Fatigue fracture through a rear flange bolt hole of the combustion chamber outer case at the three o'clock position of the engine. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive; 2 related events involving the same aircraft type or operator are linked below.

Sourcesthe U.S. National Transportation Safety Board (NTSB) historical archivePrimary reportUpdated 2026-06-10Data APIEditorial standards

During takeoff, the left engine suffered an uncontained failure due to a fatigue fracture through a rear flange bolt hole of the combustion chamber outer case. The fracture occurred 2,060 cycles before the next scheduled inspection.

Event Description

During the takeoff phase, an uncontained failure of the left engine occurred. Examination of the engine revealed a fatigue fracture that propagated through a rear flange bolt hole of the combustion chamber outer case. The fracture was located at the three o'clock position of the engine.

Inspection History

The engine had been inspected in accordance with an applicable airworthiness directive. However, the fracture occurred 2,060 cycles prior to the next scheduled inspection under that directive. Following the examinations of the engine and the fracture, additional inspection requirements were established.

Findings

The metallurgical examination identified the fracture as a fatigue failure. The source does not specify any other contributing factors.

Conclusion

The uncontained failure was directly attributed to the fatigue fracture at the described location. No further details regarding the aircraft, operator, or injuries were provided in the source.

Probable cause

Fatigue fracture through a rear flange bolt hole of the combustion chamber outer case at the three o'clock position of the engine.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001206X01206. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.