Casualties unknown

Uncontained Engine Failure During Cruise Flight (N74JM)

Melbourne, FL, US

On December 19, 1993, an Israel Aircraft Industries 1124 (registration N74JM) was involved in an aviation accident near Melbourne, FL. Investigators recorded the probable cause as: A machining anomaly and reduced fatigue life due to substandard heat treatment of the disk material, which led to the separation of a segment near the rim of the second stage low pressure turbine disk. 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 2026-06-10Data APIEditorial standards

A flight experienced an uncontained failure of the number two engine while in cruise flight, resulting in an uneventful landing. Examination revealed a turbine disk separation due to manufacturing defects.

What happened

During cruise flight, the aircraft experienced an uncontained failure of the number two engine. Despite the severity of the mechanical issue, the crew managed to execute an uneventful landing without further incident.

The investigation

Post-accident examination of the number two engine revealed that a small segment near the rim of the second stage low pressure turbine disk had separated. A detailed metallurgical analysis was conducted to determine the root cause of this structural failure.

Findings

The investigation determined that the separation was caused by a machining anomaly combined with reduced fatigue life due to substandard heat treatment of the disk material. These manufacturing defects compromised the integrity of the turbine disk, leading to the in-flight failure.

Probable cause

A machining anomaly and reduced fatigue life due to substandard heat treatment of the disk material, which led to the separation of a segment near the rim of the second stage low pressure turbine disk.

Investigation report by the U.S. National Transportation Safety Board (NTSB) historical archive. Original record: https://carol.ntsb.gov/event/20001211X13890. This page is a structured re-presentation; facts and quotes are in the National Transportation Safety Board (NTSB), United States.