NTSB Reveals Boeing Dismissed Defect Risk Years Before Fatal UPS Crash
Louisville, Thursday, 15 January 2026.
NTSB investigators have determined that Boeing identified the specific engine mount flaw behind the fatal 2025 UPS crash nearly 15 years ago. Critically, the manufacturer previously deemed the defect a non-safety issue despite multiple known failures, raising urgent questions about historical oversight and risk assessment.
Missed Warning Signs
The National Transportation Safety Board (NTSB) released a pivotal update on Wednesday, January 14, 2026, regarding the investigation into the catastrophic crash of UPS Airlines Flight 2976 [1][5]. Investigators revealed that a structural failure in the aircraft’s engine mount—specifically the spherical bearing race—was consistent with a defect Boeing (BA) had identified nearly 15 years prior [2][5]. Despite documenting four similar fractures on three different aircraft by February 2011, the manufacturer concluded at the time that the issue did not pose a threat to flight safety [1][4]. This assessment is now under intense scrutiny, as the failure of this specific component is believed to be the primary cause of the engine separating from the wing [1].
Anatomy of a Known Failure
The crash, which occurred on November 4, 2025, at Louisville Muhammad Ali International Airport, resulted in the deaths of three crew members and 12 individuals on the ground [1][2]. According to the NTSB’s forensic analysis conducted in Washington, D.C., the spherical bearing race on the left pylon lug showed clear evidence of fatigue cracking and overstress [3]. The timeline of the disaster was incredibly brief; flight recorder data indicates that a warning bell sounded just 37 seconds after the crew applied takeoff thrust [2]. At that moment, the left wing caught fire and the engine detached while the aircraft was only 9.1 meters off the ground [2].
Regulatory and Operational Fallout
The ramifications of the Louisville disaster have rippled through the global air cargo industry. Following the accident, major operators including UPS and FedEx grounded their fleets of McDonnell Douglas MD-11, MD-10, and DC-10 aircraft—models inherited by Boeing after its 1997 merger with McDonnell Douglas [5]. These aircraft have been sidelined since November 8, 2025, pending rigorous inspections or modifications mandated by the Federal Aviation Administration (FAA) [2][5]. The NTSB is currently reviewing how operators utilized the 2011 service letter and examining the correspondence between Boeing and the FAA regarding the defect’s classification [2].