In brief
In 2011, Boeing identified issues with a critical part pertaining to the engine mounts of the MD-11 aircraft, but deemed it not a safety threat. This came to light following a 2025 crash of a UPS plane shortly after takeoff in Louisville, which killed 15 people. Investigators found cracks in the engine mount parts, raising concerns about inspection practices and the responses of both Boeing and UPS to warnings about potential failures.
Boeing warned plane owners in 2011 about a broken part that contributed to a UPS plane crash that killed 15 last year but at that point the plane manufacturer didn’t believe it threatened safety, the National Transportation Safety Board said Wednesday.
The UPS plane crashed in November 2025 shortly after taking off in Louisville, Kentucky, when the left engine flew off the wing as the plane rolled down the runway.
The NTSB said Wednesday that Boeing had documented in 2011 there were four previous failures of a part that helps secure the MD-11’s engines to the wings on three different planes, but at that point the plane manufacturer determined it would not result in a safety of flight condition.
The NTSB previously said investigators found cracks in some of the parts that held the engine to the wing. Those cracks hadn’t been caught in regular maintenance done on the plane, which raised questions about the adequacy of the maintenance schedule.
It’s not clear when the cracks started to develop; however, this crash is reminiscent of a 1979 incident when the left engine detached from an American Airlines DC-10 during takeoff. This led to a catastrophic crash that killed 273 people, implicating design flaws similar to those seen in the MD-11.
NTSB investigators are now looking closely at the failure of the spherical bearing race, which was broken into two pieces after the UPS crash. Meanwhile, both Boeing and UPS expressed condolences but declined to comment further while investigations continued.
The MD-11 model, now seen as outdated, has been grounded since the crash, marking the end of its use in commercial airlines.
