NTSB Identifies Engine Mount Failure in Deadly UPS MD-11 Crash

Investigators with the National Transportation Safety Board have identified the specific aircraft component that failed in last year’s fatal UPS cargo plane crash in Louisville, shedding new light on a tragedy that killed 15 people and raising fresh questions about long-standing maintenance and oversight practices.

In a rare investigative update, the NTSB said a three-inch-wide metal bearing housing, critical to securing the left engine to the aircraft’s wing, showed evidence of pre-existing metal fatigue and cracking. The failed part—known as a bearing race—split into two pieces, allowing the left engine to detach, flip up and over the wing, and erupt into a fireball moments after takeoff.

The crash occurred on Nov. 4, 2025, shortly after UPS Flight 2976 lifted off from Louisville Muhammad Ali International Airport en route to Hawaii. Data showed the aircraft never climbed above roughly 30 feet before slamming into industrial buildings near the runway, scattering debris across a half-mile area and triggering a massive blaze. All three pilots onboard and 12 people on the ground were killed.

The NTSB emphasized that the bearing housing had been flagged more than a decade earlier. In 2011, Boeing—which assumed support for the MD-11 after acquiring McDonnell Douglas—issued a service letter to operators noting four prior failures of engine bearing races on three MD-11 aircraft. At the time, Boeing determined the issue did not constitute a “safety of flight” condition and recommended only visual inspections at standard five-year intervals.

Investigators now say fatigue cracks in the engine mount hardware went undetected during routine maintenance. The last detailed inspection of those components occurred in October 2021, and the aircraft was not scheduled for another for roughly 7,000 additional takeoffs and landings—raising concerns about whether inspection intervals were adequate for aging airframes.

The findings have drawn comparisons to the 1979 American Airlines DC-10 crash in Chicago, in which an engine separated during takeoff, killing 273 people. Former FAA and NTSB investigator Jeff Guzzetti said it is notable that similar bearing failures were once classified as safety-critical, questioning why the 2011 Boeing notice did not carry the same urgency.

The NTSB stressed that its report does not assign blame. A final report—expected 18 to 24 months after the crash—will determine probable cause and issue safety recommendations. Still, the update is likely to play a central role in ongoing and future lawsuits examining what Boeing knew and how UPS responded.

All remaining MD-11s and related DC-10 variants were grounded after the crash. As the investigation continues, the Louisville accident is increasingly viewed as a stark warning about aging aircraft, inspection standards, and the limits of non-mandatory service bulletins—issues with implications well beyond a single tragedy.

Sources: AirGuide Business airguide.info, bing.com, yahoo.com