American Airlines Flight 191 and UPS Flight 2976 were not identical accidents, but their similarities have drawn serious attention from investigators and aviation safety experts.
On 25 May 1979, American Airlines Flight 191 began what should have been a routine mid-afternoon departure from Chicago O’Hare International Airport (ORD).
The aircraft, a McDonnell Douglas DC-10-10 bound for Los Angeles International (LAX), was carrying 258 passengers and 13 crew members. As it accelerated down Runway 32R and rotated into the air, the unthinkable happened. The left engine and pylon broke away from the wing, ripping off a section of the leading edge as it separated. The engine fell onto the runway while the aircraft continued climbing, briefly reaching about 325 feet.
What followed happened in seconds.
With the engine gone, the left wing’s leading-edge slats retracted unevenly. That left wing stalled without warning, and the DC-10 rolled sharply to the left (its maximum bank was recorded as 112º). Just 31 seconds after takeoff, it crashed into an open field near a trailer park, roughly 4,600 feet from the runway. All 271 people aboard were killed, along with two people on the ground.
The NTSB later determined that the disaster was caused as a result of an asymmetrical stall and the resulting roll, caused by the uncommanded retraction of the left wing’s outboard leading-edge slats. The failure was traced back to maintenance-induced damage that led to the separation of the No. 1 engine and pylon assembly.
Investigators found that American Airlines’ maintenance procedure, which included the use of a forklift to support the engine and pylon during removal and reinstallation, had caused hidden structural damage to the pylon’s upper flange. In the aftermath, the FAA grounded the DC-10 fleet for 37 days while inspections and repairs were carried out.
More than four decades later, Flight 191 remains the deadliest single-aircraft crash in United States history.
Aviation safety expert Steve Forness, managing director of Air Flight Technical, later pointed to the design vulnerability exposed that day. In both the DC-10 crash and the later UPS accident, he noted, the engine appeared to rotate around the forward bulkhead before leaving the wing entirely.
A Reputation the DC-10 Never Fully Recovered From
The crash did more than destroy one aircraft. It severely (and permanently) damaged the DC-10’s reputation.
In the days that followed, the FAA temporarily revoked the aircraft’s type certificate, grounding all US-registered DC-10s and banning foreign DC-10s from American airspace. Even after fixes were made to the slats, warning systems, and power supplies, public confidence never fully returned.
Following Flight 191, the DC-10 became a symbol of risk for the flying public – whether that reputation was entirely fair or not. Sales suffered. McDonnell Douglas lost roughly $200 million in market value, and production of the DC-10 ended in 1989 after 386 aircraft had been built.
Aviation has always had aircraft that were technically improved after tragedy. But public perception can be harder to repair than metal.
Louisville: UPS Flight 2976
On 4 November 2025, another McDonnell Douglas trijet was rolling down a runway when history seemed to echo in a chilling way.
UPS Airlines Flight 2976, an MD-11F freighter, was departing Louisville Muhammad Ali International Airport (SDF) for Honolulu (HNL). The aircraft had been built in 1991 and had accumulated nearly 93,000 flight hours and more than 21,000 cycles. Three crew members were on board.
Shortly after V1 on Runway 17R, the left engine and pylon separated from the aircraft.
The MD-11 climbed only about 30 feet before losing control. It crashed into an industrial area south of the airport, striking several buildings and erupting in flames. All three crew members were killed, along with 12 people on the ground. One of those victims died from injuries 51 days later, bringing the final death toll to 15. Another 23 people on the ground were injured.
It was the deadliest accident in UPS Airlines history.
The NTSB’s preliminary report and later hearings identified fatigue cracks in the left pylon’s aft mount, particularly in the aft and forward lugs of the spherical bearing assembly. Investigators found that metal fatigue and overstress led to the failure.
The similarities to American Airlines Flight 191 were impossible to ignore. Both aircraft came from the same McDonnell Douglas wide-body trijet lineage. Both lost the left No. 1 engine and pylon during takeoff. Both aircraft became uncontrollable almost immediately. Both crashes ended in fire, fatalities, and loss of life on the ground.
In response, the FAA temporarily grounded the MD-11 fleet. This represented a fairly significant portion of the UPS fleet (about 9% of its total fleet). In the weeks following Flight 2976, the airline announced the accelerated retirement of its remaining MD-11s, completing the phaseout in early 2026.
Former NTSB major accident investigator Stephen Carbone raised concerns about oversight of heavy maintenance, warning that airlines can lose control when major maintenance work is outsourced. He pointed to the need for stronger FAA and airline oversight of third-party maintenance, repair, and overhaul providers.
The Parallels, the Differences, and the Lesson
The similarities between American Airlines Flight 191 and UPS Flight 2976 are striking, but the accidents were not identical.
The 1979 crash happened because of maintenance damage during engine removal and reinstallation. The 2025 crash, based on the NTSB’s findings so far, was caused by long-term metal fatigue in a key bearing assembly. One accident was due to a harmful maintenance procedure. The other involved an old structural part that failed after many years of use.
Still, both accidents point to the same uncomfortable truth: the engine-pylon structure on these aircraft was a critical area where failure could quickly become catastrophic.
During NTSB hearings, FAA technical expert Dr. Melanie Violette explained that the severity of a bearing failure had been misunderstood decades earlier. It was not believed, at the time, to be critical to the aircraft’s integrity or safety.
That detail may become one of the most important lessons from Louisville.
Commercial aviation is vastly safer today than it was in 1979. Maintenance practices, inspection technology, crew training, certification standards, and oversight have all improved dramatically. But Flight 2976 shows that even mature aircraft designs can still hold hidden risks, especially as fleets age and airframes remain in demanding cargo service long after their passenger careers have ended.
The DC-10 and MD-11 are now largely gone from the skies, with only a few exceptions still flying. But the lessons from Chicago and Louisville will likely remain part of the safety conversation for years to come.
Commercial aviation is much safer now than in 1979, but Flight 2976 showed how quickly an older, proven design can become dangerous if a hidden structural problem is missed. This is especially true for cargo planes, which often continue flying long after their passenger service ends and undergo many demanding flight cycles.
The DC-10 and MD-11 are mostly gone from regular service, but the issues raised by the Chicago and Louisville crashes will not be forgotten soon. Now, investigators, airlines, regulators, and maintenance teams are focused on finding what was missed, understanding why, and making sure this kind of failure does not happen again.
The final NTSB report for Flight 2976 will be released this November.
