Because Boeing did nothing to replace a defective part, an airplane crashed killing fifteen
Click for NTSB report.
Despite previously identifying stress fractures in a part that held the engines to the wing on three different MD-11 airplanes, Boeing did nothing to replace the part, and so fifteen people died when the engine fell off a UPS cargo plane at take-off in November 2025.
The sequence of images to the right, which I have annotated to show the engine breaking free from the wing, comes from the NTSB preliminary investigation report [pdf]. From the article at the link above:
In an update to its ongoing investigation into the crash of UPS Flight 2976, the National Transportation Safety Board [NTSB] said its team found fatigue cracking and overstress failure across much of the bearing race inside the area that attached the plane’s left engine to its wing. NTSB investigators then went back into Boeing service data and confirmed the design of the bearing assembly was consistent with the original design of that part.
[A] Boeing Service Letter dated Feb. 7, 2011 [and found by the NTSB], told operators the company was aware of four previous bearing race failures on three different airplanes. Boeing had seen the fractures of the bearing race, with the parts splitting in two and moving out of place. However, Boeing told operators its review of the bearing failure “would not result in a safety of flight condition.”
Boeing said further regular inspection of MD-11 airplanes would include a look at this bearing assembly, something scheduled for 60-month service intervals. And while Boeing used that service letter to discuss a new bearing assembly configuration, the installation of the original parts “was not prohibited.”
The plane itself had been built by McDonnell-Douglas, prior to its merger with Boeing. Nonetheless, Boeing engineers and managers were aware of this issue and did nothing to inform the owners of this plane so they could take action. In fact, Boeing apparently continued to ship out the original parts to airlines as replacement spares.
This is another example of a serious quality control problem at Boeing, where engineers no longer view serious engineering failures as serious engineering failures.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Click for NTSB report.
Despite previously identifying stress fractures in a part that held the engines to the wing on three different MD-11 airplanes, Boeing did nothing to replace the part, and so fifteen people died when the engine fell off a UPS cargo plane at take-off in November 2025.
The sequence of images to the right, which I have annotated to show the engine breaking free from the wing, comes from the NTSB preliminary investigation report [pdf]. From the article at the link above:
In an update to its ongoing investigation into the crash of UPS Flight 2976, the National Transportation Safety Board [NTSB] said its team found fatigue cracking and overstress failure across much of the bearing race inside the area that attached the plane’s left engine to its wing. NTSB investigators then went back into Boeing service data and confirmed the design of the bearing assembly was consistent with the original design of that part.
[A] Boeing Service Letter dated Feb. 7, 2011 [and found by the NTSB], told operators the company was aware of four previous bearing race failures on three different airplanes. Boeing had seen the fractures of the bearing race, with the parts splitting in two and moving out of place. However, Boeing told operators its review of the bearing failure “would not result in a safety of flight condition.”
Boeing said further regular inspection of MD-11 airplanes would include a look at this bearing assembly, something scheduled for 60-month service intervals. And while Boeing used that service letter to discuss a new bearing assembly configuration, the installation of the original parts “was not prohibited.”
The plane itself had been built by McDonnell-Douglas, prior to its merger with Boeing. Nonetheless, Boeing engineers and managers were aware of this issue and did nothing to inform the owners of this plane so they could take action. In fact, Boeing apparently continued to ship out the original parts to airlines as replacement spares.
This is another example of a serious quality control problem at Boeing, where engineers no longer view serious engineering failures as serious engineering failures.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon or from any other book seller. If you want an autographed copy the price is $60 for the hardback and $45 for the paperback, plus $8 shipping for each. Go here for purchasing details. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
I’m going to push back slightly on the last sentence, because Boeing has forced out a good many engineers over the decades (up to the present day), and management has frequently been the culprit for stupid decisions made at the company. It may be the engineers saying so, but I’d bet money that it’s management somewhere saying to ignore it.
Nate P: You have a point, though I think a relatively weak one. Just because management orders you to ignore a dangerous situation is no excuse for obeying that order.
Regardless, this problem is as much management’s as the engineers. I have added “management” to my next-to-last paragraph to make this clear.
MD-11 is just DC-10 in drag
As in MacDoug…the real culprit.
DC-10s failed the same way…a piece of one of those garbage scows hit Concorde and caused its only crash.
Robert Zimmerman: true. Engineers should push back regardless of what management says, and it’s on them if they didn’t.