NTSB Releases Frame-by-Frame Images of UPS MD-11 Engine Separating in Louisville; Investigators Point to Metal Fatigue Cracks in Pylon
The NTSB released frame-by-frame surveillance stills showing a UPS MD-11F’s left engine and pylon separating during rotation at Louisville’s KSDF on November 4, 2025, an incident tied to metal fatigue cracks and resulting in 14 fatalities.
- Visual timeline: Multiple airport cameras captured the engine and pylon detaching during rotation, enabling a detailed frame-by-frame reconstruction.
- Probable factor: Investigators have focused on metal fatigue cracks in the left engine pylon and fractured attachment hardware.
- Human toll: The crash killed 14 people — three crew members and 11 on the ground.
- Ongoing work: Metallurgical and laboratory testing of the pylon, bearing and clevis components is underway.
- Local implications: Findings could affect inspection rules, costs and operational practices for cargo operators, including those serving San Diego.
What the NTSB images show
The NTSB released a sequence of stills taken from airport surveillance cameras that capture the MD-11F as it rotated for takeoff and the left engine with its pylon detaching from the wing. The frames depict the engine lifting, passing over the fuselage, then striking the ground and a near‑immediate fireball developing close to the left wing attachment area.
Because multiple cameras recorded the event from different angles, investigators were able to create a precise, frame-by-frame timeline tying the separation to the airplane’s attitude and rotation. See the ABC News coverage and the surveillance footage cited by investigators: ABC News report and images and the surveillance video referenced by the NTSB release.
Preliminary technical findings: metal fatigue cracks in pylon
Early on-site and laboratory examinations have concentrated on the pylon — the structural assembly that connects the engine to the wing. The NTSB’s preliminary report and reporting from trade press indicate signs consistent with metal fatigue cracking around the pylon attachment hardware that likely led to progressive failure and eventual separation during the high loads of rotation for takeoff.
Investigators reported that part of the wing clevis remained attached to the spherical bearing after separation and that the bearing’s outer race was fractured, exposing the ball element. That observation suggests a localized failure in the bearing and attachment hardware requiring detailed metallurgical analysis to determine whether fatigue developed over time, a manufacturing defect existed, or other factors accelerated the break.
Key reference documents and reporting include the NTSB preliminary report (DCA26MA024), Flying Magazine, and coverage from AVweb and FreightWaves.
Flight path, impact and immediate aftermath
Investigators and the released images indicate the MD-11 climbed to roughly 30 feet above ground level before control was lost. The detached engine struck the ground and a fire began near the wing attachment; the aircraft then descended into nearby buildings just beyond the airport boundary, producing a catastrophic breakup nearly instantaneous with rotation for takeoff.
NTSB documentation indicates there were no reported anomalies during taxi or the initial takeoff roll and that the crew did not report warning lights or system messages prior to rotation. For details, consult the NTSB preliminary report.
How surveillance video aided the probe
“The footage provided a precise visual record to match against flight data and maintenance records,” investigators said, using the frames to narrow parts for examination and tests.
Surveillance frames supply exact timing and motion, allowing the NTSB to correlate the moment of separation with aircraft attitude, speed and rotation angle. That clarity guided the investigative focus toward the pylon attachment hardware and spherical bearing evidence.
Ongoing engineering and metallurgical analysis
NTSB teams are conducting detailed metallurgical testing on the fractured bearing, pylon components and attachment hardware. These tests aim to establish whether cracks resulted from long-term fatigue, a manufacturing defect, maintenance oversight, or a mix of factors. Investigators will also review the aircraft’s maintenance history and inspection records to see if earlier signs were missed.
Note: While reporting and early findings center on pylon fatigue cracks, the NTSB has not issued a final probable cause and will await full lab results, witness statements, flight-data analysis and supplier records before declaring a final determination.
Reactions and implications for San Diego, California
Although the crash occurred in Louisville, the potential regulatory and operational consequences are national. San Diego’s logistics and air-cargo sector could face higher inspection or retrofit costs and possible operational disruptions if new rules or directives emerge. Local leaders, airport operators and cargo companies should monitor developments and consider reviewing maintenance records and contingency plans.
Practical implications include:
- Airport operators and maintenance providers should review inspection intervals and training programs for aging aircraft structures.
- Businesses reliant on rapid air freight should assess contingency plans for potential service disruptions.
- Residents near airports may renew calls for stronger community emergency planning and clearer communication from authorities.
Sources and documents
Primary sources cited in this article:
- NTSB preliminary report (DCA26MA024)
- Flying Magazine
- AVweb
- ABC News report and images
- FreightWaves analysis
- Surveillance video referenced by NTSB release
Reporting continues as investigators perform laboratory tests and review records; updates and the NTSB’s final findings will provide further detail on causation and potential safety recommendations.
