NTSB Preliminary Findings on UPS Flight 2976 Engine Failure Crash

NTSB Releases Preliminary Findings on UPS Flight 2976 Accident

On November 20, 2025, the National Transportation Safety Board (NTSB) released its Preliminary Report regarding the catastrophic loss of UPS Flight 2976. The accident, which took place on the evening of November 4, 2025, involved a McDonnell Douglas MD-11F Cargo-Aircraft departing from Louisville Muhammad Ali International Airport (SDF). The crash resulted in the fatalities of all three crew members on board and 11 individuals on the ground, marking the deadliest accident in the history of UPS Airlines. The release of this report provides the first official technical insight into the sequence of events leading to the tragedy.

The investigation, identified as DCA26MA024, has drawn significant attention from the aviation industry and the general public due to the severity of the ground impact and the age of the airframe involved. While the investigation is ongoing and a final determination of probable cause may take a year or more, the preliminary data points to a critical structural failure during the takeoff sequence. The NTSB’s initial findings focus heavily on the separation of the aircraft’s left engine and the integrity of the pylon structure connecting it to the wing.

We are analyzing the details provided in the preliminary report to understand the mechanical and operational factors at play. This article breaks down the factual sequence of events, the specific mechanical failures identified by investigators, the human cost of the accident, and the immediate regulatory and industrial responses that have followed. The information presented here is based strictly on the NTSB preliminary report and verified data available as of November 20, 2025.

Structural Failure and Flight Sequence

According to the NTSB preliminary report and corroborated surveillance footage, the accident sequence began during the takeoff roll on Runway 17R. The aircraft, registered as N259UP, appeared to function normally during the initial acceleration. However, the situation deteriorated rapidly at the moment of rotation, the point where the nose of the aircraft lifts off the ground to begin the climb. Investigators have determined that as the aircraft rotated, the No. 1 engine, located on the left wing, physically separated from the aircraft along with its pylon structure.

Analysis of the Engine Separation

Surveillance video reviewed by the NTSB captured the engine traversing over the fuselage after detaching, subsequently falling to the ground within the airport perimeter. The separation caused an immediate and massive fire at the attachment point on the left wing. The No. 1 engine and the majority of the pylon structure were recovered on the grass adjacent to Runway 17R, confirming that these critical components were lost before the aircraft had fully departed the airport environment. This separation significantly compromised the aircraft’s aerodynamics and structural integrity.

Following the separation, the aircraft managed to climb briefly to an altitude estimated between 100 and 175 feet Above Ground Level (AGL). The Cockpit Voice Recorder (CVR) data indicates that a “repeating bell” sound began 37 seconds after takeoff thrust was set and continued until the recording ceased. The aircraft was unable to maintain altitude or directional control, banking sharply to the left. The flight path ended when the left main landing gear impacted the roof of a UPS Supply Chain Solutions warehouse, followed by a crash into a nearby industrial park.

“Investigators identified metal fatigue cracks on the aft mount and spherical bearing of the left engine pylon. The outer ring of the spherical bearing was fractured around its entire circumference.”

Metallurgical Findings and Maintenance History

The focus of the investigation has narrowed to the structural components holding the engine to the wing. The NTSB report highlights the discovery of metal fatigue cracks on the aft mount and the spherical bearing of the left engine pylon. Specifically, cracks were present on both fracture surfaces of the aft lug, and the outer ring of the spherical bearing was found fractured around its entire circumference. These findings suggest a pre-existing structural weakness that ultimately failed under the stress of takeoff.

Maintenance records for N259UP are currently under intense scrutiny. The 34-year-old aircraft had recently undergone heavy maintenance in San Antonio, Texas, approximately six weeks prior to the accident. Investigators are working to determine whether the fatigue cracks were present and undetectable during that maintenance visit, or if they developed rapidly in the short period following the service. The aircraft had accumulated over 21,000 flight cycles and 92,000 flight hours since its manufacture in 1991.

Casualties and Ground Impact

The crash of Flight 2976 resulted in a significant loss of life, impacting both the flight crew and the local community in Louisville. The accident site, located in an industrial area immediately south of the Airports, sustained heavy damage, particularly to the Grade A Recycling facility and a Kentucky Petroleum Recycling depot. The impact caused a massive post-crash explosion and fire, complicating rescue efforts and increasing the severity of the incident.

The Flight Crew

The three crew members operating the flight were fatally injured in the crash. The flight was commanded by Captain Richard Wartenberg, 57, a resident of Independence, Kentucky, and a retired U.S. Air-Forces Lieutenant Colonel with the 445th Airlift Wing. He was accompanied by First Officer Lee Truitt, 45, from the Louisville area, and Captain Dana Diamond, 62, who was serving as the International Relief Officer. Their experience and backgrounds highlight the tragic loss of seasoned aviation professionals.

Impact on the Community

The ground casualties were concentrated in the industrial facilities struck by the aircraft. Eleven individuals on the ground lost their lives. Among the identified victims were Louisnes “Lou” Fedon, 47, a customer at the recycling center, and his three-year-old granddaughter, Kimberly Asa. Other victims included Matt Sweets, 37, an electrician working in the area who succumbed to severe burns two days after the crash, and Angela Anderson, 45, who was located at the Grade A Recycling center. The crash also resulted in injuries to 23 other individuals, with two listed in serious condition.

Industry Implications and Regulatory Actions

The release of the preliminary findings has triggered immediate responses across the aviation logistics sector. The identification of pylon fatigue as a primary factor has led to precautionary measures regarding the McDonnell Douglas MD-11F fleet, a workhorse of the global air cargo industry. The implications of these findings extend beyond UPS, affecting other major operators and maintenance organizations.

Fleet Groundings and Directives

In response to the crash, UPS Airlines immediately grounded its entire fleet of MD-11F aircraft out of an abundance of caution. FedEx Express, the other primary operator of the MD-11F, followed suit by grounding its fleet pending inspections. These voluntary groundings were reinforced by regulatory action; the Federal Aviation Administration (FAA) issued Emergency Airworthiness Directives (AD) requiring immediate inspections of engine pylons on all MD-11 and DC-10 series aircraft. These directives are mandatory and aimed at detecting any similar fatigue cracking in the active fleet.

Future Outlook for the MD-11F

The grounding of two major MD-11 fleets is expected to cause notable disruptions in global air cargo logistics, particularly for long-haul heavy freight where the MD-11F is frequently utilized. As the manufacturer via merger, Boeing is a party to the investigation. The focus on metal fatigue in aging airframes may lead to the implementation of more rigorous maintenance protocols for the remaining MD-11 fleets globally. The industry will be closely monitoring the ongoing investigation to see if further structural modifications or retirement schedules will be recommended for this aircraft type.

Conclusion

The NTSB’s preliminary report on UPS Flight 2976 provides a factual baseline for understanding the mechanical failure that led to this tragedy. The identification of fatigue cracking in the engine pylon structure shifts the focus of the investigation toward maintenance practices, material fatigue management, and the aging of the global cargo fleet. As the investigation continues, the NTSB will work to establish the root cause of the fatigue and why it went undetected.

For the families of the 14 victims and the aviation community, the report offers initial answers but highlights the complexities of aviation safety. The coming months will likely see continued disruptions in cargo logistics as inspections proceed, alongside a broader industry conversation regarding the longevity and inspection requirements of older freighter aircraft.

FAQ

What caused the crash of UPS Flight 2976?
According to the NTSB preliminary report, the primary cause was the structural failure and separation of the No. 1 (left) engine and its pylon from the wing during takeoff, caused by metal fatigue cracking.

How many people died in the accident?
There were 14 total fatalities: 3 crew members on board the aircraft and 11 individuals on the ground.

What is the status of the MD-11F fleet?
Following the crash, both UPS Airlines and FedEx Express grounded their MD-11F fleets. The FAA has issued Emergency Airworthiness Directives requiring immediate inspections of engine pylons on these aircraft types.

When was the aircraft last serviced?
The aircraft, N259UP, had undergone heavy maintenance in San Antonio, Texas, approximately six weeks prior to the accident.

Sources

• NTSB Preliminary Report DCA26MA024