A damning new report from US investigators has revealed that Boeing was aware for years of a critical part's failure history before it broke on a UPS cargo plane, leading to a catastrophic crash that claimed 15 lives.
The Crash and Its Immediate Aftermath
The accident occurred on 4 November last year at Louisville Muhammad Ali International Airport in Kentucky. The UPS McDonnell Douglas MD-11, bound for Honolulu, Hawaii, suffered a failure of its left engine during its take-off roll. It managed to become airborne for a mere 30 feet before crashing, killing all three crew members on board and 12 people on the ground. The devastation led to the suspension of all flights at the airport.
A Known History of Failures
According to the US National Transportation Safety Board (NTSB) report published on Wednesday, Boeing had known since at least 2011 that the part, which helps secure engines to the wings, had failed four separate times on three different aircraft. Despite this, the plane maker at the time determined the issue would not create an unsafe flight condition.
In 2011, Boeing issued a service bulletin to airlines warning of the problem. However, this notice did not carry the mandatory force of an airworthiness directive from the Federal Aviation Administration (FAA), which regulators never issued. Former federal crash investigator Alan Diehl explained to the Associated Press that Boeing's bulletin recommended replacing the problematic bearings with a redesigned, safer part.
Critically, operators were still permitted to replace defective bearings with older versions of the same part, which were known to be prone to failure.
Maintenance and Investigation Questions
The NTSB confirmed investigators found cracks in the engine mount parts on the crashed plane. These cracks were missed during routine maintenance, raising serious questions about the adequacy of the aircraft's inspection schedule. The parts had last undergone a detailed examination in October 2021 and were not due for another such inspection for a further 7,000 take-offs and landings.
While the NTSB's latest report details these facts, it does not state the definitive cause of the engine loss; that conclusion awaits the board's final report. All MD-11s and ten related DC-10 aircraft have been grounded since the tragedy.
The report is expected to feature heavily in lawsuits already filed over the crash. A Boeing spokesperson expressed the company's deepest condolences and stated they continue to support the NTSB investigation. UPS said it remained "profoundly saddened" and was focused on the recovery effort, but could not comment further while the probe continues.
The aircraft type involved, the MD-11, has long been retired from passenger service but continues to be flown by major cargo carriers like UPS and FedEx.
