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LOUISVILLE — The National Transportation Safety Board (NTSB) has released its preliminary findings on the catastrophic crash of UPS Flight 2976, a McDonnell Douglas MD-11F that went down shortly after takeoff from Louisville Muhammad Ali International Airport (SDF) on November 4, 2025.
All three crew members on board were killed, along with 11 people on the ground. Another 23 individuals on the ground sustained injuries. The aircraft, N259UP, was destroyed.
The Part 121 cargo flight was bound for Honolulu (HNL) when it suffered a structural failure within seconds of liftoff. The early evidence points to one of the most serious MD-11 structural breakup events since the type entered service.
Engine, Pylon Separation Seconds After Rotation
Airport surveillance cameras captured the moment the left (No.1) engine and its pylon separated from the wing just after rotation from Runway 17R. The NTSB notes that the engine detached while the aircraft was still low and accelerating, igniting a fire as it arced over the fuselage before impacting the ground. The pylon attachment point on the wing also erupted in flames.
Flight data indicates the aircraft never climbed beyond ~30 feet AGL, clearing the runway’s blast fence by a narrow margin. The left main landing gear then struck the roof of a UPS warehouse at the southern airport boundary. The aircraft continued another 3,000 feet before breaking apart and erupting into a post-impact fire that consumed multiple structures, including a petroleum recycling facility, along its ground track.
Figure 1. from the report shows still images from an airport surveillance video showing, frame by frame, the left engine and left pylon separation from the left wing. (Source: UPS)
Immediate Loss of Control
According to tower witnesses, rotation itself appeared normal, but the aircraft “failed to climb” and began sinking almost immediately. Another observer reported the MD-11 entering a shallow left roll as it lost altitude, consistent with a sudden asymmetric thrust and lift condition following engine-pylon separation.
ADS-B showed a final altitude of 481 ft MSL (~100 ft AGL) before data ceased.
Crew Background
All three pilots, Captain, First Officer (pilot flying), and Relief Officer, were experienced MD-11 aviators:
- Captain: ~8,613 total hours, 4,918 on MD-11
- First Officer: ~9,200 total hours, 994 on MD-11
- Relief Officer: ~15,250 total hours, 8,775 on MD-11
No abnormalities in crew qualifications or regulatory compliance were noted.
Key Structural Failure: Fatigue Cracks in the Aft Pylon Mount
Investigators immediately focused on the left pylon’s aft mount, which connects the engine pylon to a wing clevis using a spherical bearing and attachment hardware. The NTSB recovered fractured lugs from the aft mount showing both fatigue cracking and overstress failure.
Notably:
- Fatigue cracks were found on both the inboard and outboard surfaces of the aft lug.
- The spherical bearing’s outer race had fractured circumferentially, exposing the ball element.
- The forward lug exhibited fatigue cracking on the inboard surface; the outboard fracture showed overstress without fatigue indications.
These findings suggest that progressive fatigue damage, not a single overload event, compromised the pylon attachment before separation.
The right engine pylon showed separation of its mounts as well, but the right engine remained attached to the wing.
Aircraft Background and Maintenance Status
The accident aircraft had:
- 92,992 total hours
- 21,043 cycles
Maintenance records show:
- A 72-month detailed inspection of the left pylon aft mount was last performed in October 2021.
- A 24-month lubrication task (including spherical bearings) was completed just weeks before the accident (October 18, 2025).
- Two Special Detailed Inspections of the aft mount were NOT yet required, as thresholds were at 28,000–29,200 cycles.
Thus, while all maintenance was in compliance, the fatigue damage discovered suggests potential issues with intervals, load environments, or component life limits.
Fleet-wide Response: Groundings and Emergency Airworthiness Directives
UPS grounded its entire MD-11 fleet on November 7, following Boeing’s recommendation.
The FAA issued Emergency AD 2025-23-51, later superseded by 2025-23-53, grounding all MD-11 and DC-10 series aircraft until inspections and corrective actions could be completed—a sweeping action that signals the seriousness of the structural findings.
Historical Parallel: DC-10 Flight 191
The NTSB explicitly cites the 1979 crash of American Airlines Flight 191 at Chicago O’Hare: a DC-10 that also lost its No.1 engine and pylon on rotation due to faulty pylon attach structure handling during maintenance. That event remains the deadliest aviation accident in U.S. history.
The design lineage between the DC-10 and MD-11 makes the comparison particularly relevant.
Recorders Recovered, Investigation Continues
Both the CVR and FDR were recovered and successfully downloaded. Each contained complete data for the accident flight.
The NTSB’s investigation will now shift to:
- Metallurgical analysis of fracture origins
- Load environment modeling of the pylon/wing structure
- Maintenance history and inspection interval adequacy
- Fleet-wide pylon hardware condition assessments
A final report is expected later next year.
Featured image: Chris Goulet/airways
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