NTSB Preliminary Report Reveals Critical Failure in UPS Plane Crash

The National Transportation Safety Board (NTSB) has released a preliminary report detailing the catastrophic failure that led to the November 4, 2025, crash of UPS Flight 2976 at Louisville's Muhammad Ali International Airport. The investigation points to critical fatigue cracks in the aircraft's engine mounting hardware as the likely cause of the disaster that claimed 14 lives.

Tragic Sequence of Events

The MD-11F cargo jet, bound for Honolulu, experienced an uneventful taxi and initial takeoff roll. However, just moments after lifting off, the left engine and its pylon detached from the wing. The plane, which reached a maximum altitude of only 30 feet, veered left and crashed into a UPS warehouse and supply yard, creating a half-mile debris field.

The impact and subsequent fireball killed all three crew members aboard and 11 people on the ground, with 23 others sustaining injuries. Witnesses in the control tower noted the plane's climb "was not normal" before it began losing altitude.

Critical Findings: Fatigue Cracks Overstressed Mounts

Investigators recovered and meticulously examined the structural lugs—fittings that secure the engine pylon to the wing. Examination revealed microscopic fatigue cracks in these components, likely exacerbated by the stresses of repeated pressurization cycles, takeoffs, and landings. The lugs also showed signs of overstress failure at the points of attachment.

The NTSB specifically noted fatigue cracks where the aft lug bore met its forward face, along with cracks along the lug bore of the forward mount. These failures match patterns seen in previous aviation disasters.

"The airplane cleared the blast fence beyond the end of runway 17R, but the left main landing gear impacted the roof of a UPS warehouse before crashing into the supply yard." — NTSB Preliminary Report

Eerie Parallels to 1979 DC-10 Crash

The report draws a striking comparison to the 1979 crash of American Airlines Flight 191 in Chicago, which also involved a McDonnell Douglas aircraft (the DC-10, predecessor to the MD-11). In that disaster, the left engine and pylon separated during takeoff, causing the plane to roll and crash. Both incidents highlight vulnerabilities in engine mounting systems for older widebody aircraft.

Immediate Actions and Investigation

In response to these findings, the Federal Aviation Administration (FAA) grounded all MD-11 and MD-11F aircraft until thorough inspections could be conducted. UPS, which operates 26 MD-11 freighters, has pledged full cooperation with the ongoing investigation. The recovered cockpit voice recorder (containing 2 hours of audio) and flight data recorder (with 63 hours of data) are being analyzed at a secure facility.

The NTSB released the preliminary report in just 16 days—significantly faster than the typical 30-day timeline—underscoring the urgency of the investigation. A final report with probable causes and safety recommendations is expected within 18-24 months.

Industry Impact

The crash has renewed scrutiny on aging cargo aircraft maintenance protocols. The 34-year-old MD-11F involved in the crash was already being phased out by UPS, but the incident may accelerate retirement timelines for similar models worldwide. Boeing, which now owns McDonnell Douglas, expressed condolences and reaffirmed commitment to safety.

As investigators continue to examine maintenance records and structural components, the aviation industry awaits definitive answers to prevent such tragedies from recurring.