NTSB Links UPS Flight 2976 Crash to Long-Known Engine Issue

The National Transportation Safety Board (NTSB) has identified the cause of the crash of UPS Flight 2976, which occurred on November 4, 2025. A small but critical component, a three-inch (7.62-centimeter) mount bearing, failed, leading to the detachment of the left engine from the aircraft. This incident resulted in a fire and ultimately caused the McDonnell Douglas MD-11 to crash shortly after takeoff from Louisville, Kentucky.

In its latest update, released on January 14, 2026, the NTSB detailed how the failure of the mount bearing assembly directly contributed to the accident. The investigation revealed that the aft mount bearing housing for the left engine’s pylon had fractured, resulting in the engine and its support structure separating from the wing. Evidence of fatigue cracking was found in the damaged components, suggesting that the issue developed over time.

Background on the MD-11 and Previous Warnings

Boeing, which merged with McDonnell Douglas in 1997, had previously flagged issues related to the MD-11’s pylon bearings nearly 15 years ago. After several incidents, the FAA issued a service bulletin recommending inspections and potential replacements of the affected parts. However, compliance with these recommendations was not mandatory.

The MD-11 involved in the crash, designated N259UP, had not received the updated bearing design. This raises significant questions about UPS Airlines’ maintenance practices and whether the aircraft had undergone the necessary inspections to detect the fatigue cracking that ultimately led to the failure.

Implications for Aviation Safety and Future Operations

The crash has prompted the FAA to issue an emergency airworthiness directive, effectively grounding all US-registered MD-11 aircraft while awaiting corrective measures. Many of these planes are over 30 years old, yet airlines like FedEx Express are optimistic about returning their fleets to service soon. The findings indicate that any required repairs to the mount bearings are likely to be both cost-effective and quick to implement, thus minimizing operational disruptions.

Investigators will continue to probe why Boeing deemed the pylon bearing issue did not pose a safety risk for so long and why mandatory actions were not enforced. The NTSB is also examining whether UPS Airlines conducted thorough inspections and why the signs of fatigue were overlooked by maintenance personnel.

As the investigation unfolds, the aviation community will watch closely for the NTSB’s conclusions and the FAA’s subsequent actions. The future of the MD-11 fleet may hinge on these developments as airlines seek to balance safety with operational efficiency.