The National Transportation Safety Board opened a two-day hearing in Washington on the causes of a deadly UPS cargo plane crash at Louisville, Kentucky, and on why a recurring set of maintenance and oversight issues was not detected sooner. The hearing followed the engine separation that investigators say occurred as the MD-11 accelerated down the runway at Louisville Muhammad Ali International Airport, killing all three pilots and 12 people on the ground, with 23 others injured.
Investigators released more than 2,000 pages of documents during the proceedings as they focused on the “root causes” of the disaster, including what government regulators and industry participants did—or did not do—after earlier maintenance findings. The NTSB said the crash investigation quickly turned up cracks in parts of the engine mount, and it later found records indicating similar flaws had been spotted during maintenance on aircraft elsewhere in the fleet.
The board’s materials described how UPS switched planes hours before takeoff, after a preflight inspection found a fuel leak in the first aircraft loaded for a trip to Hawaii. After the cargo and crew moved to a second plane, investigators said the flight crew exchanged banter with the maintenance team during its inspection, before the aircraft entered takeoff.
Investigators said the second plane barely cleared the airport fence before crashing into nearby businesses in a fireball. In the aftermath, the NTSB said it examined the wreckage and found cracks in engine-mount parts that had not been caught in regular maintenance, and it raised questions about whether the maintenance schedule was adequate. The board also said that the last time the key parts were examined closely was in October 2021, with the next detailed inspection not due for roughly 7,000 takeoffs and landings.
NTSB materials also pointed to how the Louisville crash echoed an older U.S. history of engine-mount failures. The NTSB said the scene carried similarities to a 1979 Chicago crash involving a DC-10 that lost its left engine, killing 273 people, and that incident triggered a worldwide grounding of 274 DC-10s.
Within the hearings, NTSB member Tom Chapman testified about the broader pattern investigators said they found beyond the Louisville aircraft. Chapman said records showed similar flaws had been identified 10 times in other planes during the previous 15 years, but that only four were reported to the FAA, adding that investigators believed all should have been reported. FAA officials, in testimony included in the NTSB hearing record, said the four reports—spread over years—would not have been enough to demonstrate a trend.
The hearing record also included testimony about Boeing’s role in how the issue was communicated. The materials described Boeing’s position that the identified bearing flaws “would not result in a safety of flight condition,” and that Boeing therefore did not require owners to make repairs through mandatory changes. Instead, Boeing recommended that bearings be inspected more often, without altering the maintenance schedule, and the NTSB record said the FAA did not issue an airworthiness directive that would have ensured those steps were carried out.
Melanie Violette, an FAA official, testified that she believes the risks tied to spherical bearing failure in the lug were misunderstood when concern was raised in 2007. Violette said the lug was designed to be fail-safe and that one side could fail while the other continued to take the load, and she said the actual outcome during the crash differed from how the failure was understood at the time. “The lug was designed to be fail-safe so that one side could fail and the other would continue to take the load. And the failure of that one lug would be very visible and very obvious and much easier to detect,” Violette said. “The actual way things played out was not the way it was understood. So that is also an important aspect of this.”
The hearing also addressed why earlier maintenance findings may not have been treated as urgently as investigators now say they should have been. UPS officials told the NTSB that they could have done more after earlier indications, and a longtime UPS executive who oversees aircraft maintenance and repair, David Springer, said Boeing’s service letters made the bearing problem “sound almost benign” and did not mention collateral damage that could affect the lugs that attach the engine to the wing. “I think if we would have known that at UPS, I think we would have asked a lot of different questions over the years,” Springer said.
Families represented by attorney Bradley Cosgrove argued that action should have happened years earlier. Cosgrove said the failure was systemic: “What happened was a systemic failure to recognize and address a known risk before it resulted in a horrific catastrophe,” he said. The hearings included questioning among NTSB board members and investigators and representatives of Boeing, UPS, the mechanics’ union, and other parties.
Boeing told investigators that since the crash it has invested in modeling efforts to understand the stress on the part, according to testimony from Justin Konopaske, director of airframe service engineering for the manufacturer. Boeing also told the NTSB it has been looking for similar designs across aircraft it has built.
The NTSB said its final report will look at every potential factor, and it likely will not be ready until more than a year after the crash. Meanwhile, the record of the hearings described steps taken after the Louisville disaster, including changes tied to inspection and replacement of the spherical bearings on MD-11s. Federal regulators and Boeing officials also testified about how the FAA approved a plan that required bearings be replaced after every 4,000 cycles of takeoffs and landings, and airlines including FedEx have resumed using MD-11s while UPS has said it plans to retire its fleet.