NTSB Finds Evidence...
 

NTSB Finds Evidence Of Fatigue Cracks In Fatal UPS MD-11 Crash

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On November 4, 2025, we saw a horrific accident, whereby a UPS McDonnell Douglas MD-11 crashed while taking off from Louisville (SDF), killing the three pilots onboard, plus 11 people on the ground.

Continue reading: NTSB Finds Evidence Of Fatigue Cracks In Fatal UPS MD-11 Crash

Share your questions, experiences, and thoughts below.


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46 Replies
Diamond
(@tim-dunn)
Joined: 5 years ago

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cameras have revolutionized accident investigation esp. when accidents occur over land.

The DC-10 and MD-11 are finished.


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Diamond
(@fmbwi)
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I have to say I really admire the NTSB, certainly one of the most competent federal agencies.

So, if the lug had signs of stress from age or too many cycles, why would a similar thing have happened in 1979 when the plane was much newer? And hasn't happened in the ensuing 46 years?


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Diamond
(@travelinwilly)
Joined: 5 years ago

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Posts: 2563

"I have to say I really admire the NTSB, certainly one of the most competent federal agencies."

Agreed.

Now you just have to hope that they never inspect the orange Nazi baboon's antique 757 and find anything wrong with it, because if they do, the NTSB will be dismantled faster than you can say "Goodbye East Wing of the White House."


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Diamond
(@tim-dunn)
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the original investigation of the AA disaster showed that the engine had been removed from the wing using an unapproved technique which damaged the pylon.
The outcome was the same but the reasons for why it happened were considerably different.

We don't know if the cause of the latest incident could have been prevented with more intrusive inspections but the MD11/DC10 fleet left in service is fairly small - about 50 or so total in the US - and it likely will not be worth the effort to do extensive inspections or rebuilding of the pylon and its structures to keep the planes in service.

and the MD11 has been involved in a disproportionately large number of accidents related to handling - far more so than the DC10 or other models.


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Diamond
(@fmbwi)
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They should rename his plane "Pedo Air."


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Diamond
(@fmbwi)
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Thanks, that's helpful (nice to use that "helpful" button for its actual purpose!).


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(@Kirby Carmichael)
Joined: 9 months ago

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The 1979 O'Hare crash occurred due to a corner-cutting maintenance practice - use a lift-truck crane to hoist the engine/pylon combo onto the wing. This is much cheaper than the recommended manner of removing the engine from the pylon. The lift truck, however, must do the practice blind to the aft point of the pylon mount, resulting in the lift track striking the metal surface and causing invisible cracks which use enlarged. The maintenance procedure was dropped, reportedly, but the 'stress cracks' in this left pylon appear to indicate that the same cost-saving maintenance procedure continues to be used. IPS likely will not survive this.


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Diamond
(@tim-dunn)
Joined: 5 years ago

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bold prediction.
You have to wonder why the lift truck method was not banned. and UPS undoubtedly knew what was being done.

let's see how it all falls out - this is all coming to a resolution much faster than most accidents - but the real question is why the two step engine and pylon removal process was not mandated.


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 1990
(@1990)
Joined: 11 months ago

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"bold prediction."


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 1990
(@1990)
Joined: 11 months ago

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Image #4 is nightmare fuel.

Those pilots are heroes to fight to the bitter end. RIP to them and the victims.


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 Jack
(@Jack)
Joined: 12 years ago

Posts: 485

The poor engineering legacy of McDonnell Douglas lives on. It's no wonder Boeing has been such a hot mess since the merger.


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Diamond
(@bradstpete)
Joined: 5 years ago

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the 1979 incident involved the improper use of a fork lift type vehicle to change out the engine contrary to the manufacturers directives. Continental Airlines used the same procedure which caused stress and wear to the pylon. The FAA stopped that practice as soon as it was discovered.


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Diamond
(@pierre-2)
Joined: 5 years ago

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There is a big difference between this accident and that of AA 46 years ago, even though the immediate cause of both accidents was the same left engine separating from the wing:

In AA's case, it was demonstrated that during maintenance, the engine was removed and placed back using a different method than that prescribed in the plane's manual. The engine separated from the pylon at the junction point because of that error.

In this case, the cause seems attributable to fatigue cracks. There were no such cracks on AA's DC10.


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(@Christian)
Joined: 12 years ago

Posts: 844

I’m with @Jack. Before the merger, Boeing planes had comparatively few problems, after the merger where MCD management somehow came out on top the company has had one catastrophic launch after another. Coincidence?


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(@AdamH)
Joined: 16 years ago

Posts: 430

There is a lot of press pointing out this plane was old, which isn't wrong per se, but it ignores UA and DL both have multiple planes in their fleets that are all nearing the same age (75s and 76s and some older Airbuses). I get that there is some history with this general airframe of fatigue issues but it is not exactly reassuring that this was not discovered in regular maintenance and it makes me wonder if a similar issue would be discovered for the passenger jets in general.


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(@Eskimo)
Joined: 9 years ago

Posts: 6145

Delta is premium.
That's a "bold prediction."


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(@KlimaBXsst)
Joined: 4 years ago

Posts: 125

I would like to second this. Trained to do what they knew to do within all the parameters of their abilities.

May peace be with their families, their loved ones, their colleagues, and all affected during these grieving times, knowing fully Aviators love doing what they do.


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(@FlyerDon)
Joined: 5 years ago

Posts: 407

I don’t understand why the NTSB isn’t following its usual protocols. They usually don’t dribble out information like this. The wait until they know all the facts. Speaking of facts American 191 didn’t crash because it lost its engine, it crashed because its leading edge slats, on the left side, retracted, while the right side stayed extended but the flightcrew had no indication of this because the slat asymmetry and stall warning systems did not illuminate in the cockpit. The left wing stalled and the aircraft went down. If the crew knew of the asymmetry they would have flown a different profile and they would have been able to fly and land the aircraft, with or without the engine attached to the wing. I don’t know why the MD11 went down but looking at the wings it looks like all of the LE devices were still extended. Let’s be patient and wait for the investigation to conclude and the NTSB issues the probable cause.


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Diamond
(@tim-dunn)
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DL and UA don't have planes with engines falling off with the possibility that maintenance might have caused the pylon to be weakened.

Age is not the problem. taking shortcuts and doing things - whether directly through your own maintenance or through a contractor - that might be related to the most deadly aviation accident on US soil is the problem.

and, no, other airlines or their contractors don't remove widebody engines and the pylons with lift trucks.


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Diamond
(@tim-dunn)
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and yet this plane was built by McDonnell Douglas. Boeing had nothing to do with it.

Yes, Boeing has had no shortage of engineering and production issues since it "acquired" McD D but this plane had nothing to do with the merger other than being supported by Boeing post merger.


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Diamond
(@tim-dunn)
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Delta flew the L1011 other than short stints of the DC10.
The L10 simply never had the operational or engineering problems the DC10 and MD11 had.
The wrong manufacturer decided to leave the commercial aircraft manufacturing business.


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(@D3SWI33)
Joined: 9 years ago

Posts: 1705

The MD 11 sucks. They should have been grounded a long time ago with a poor track record. 757s and 767s have nothing to do with this. I was right. Well well well all you so called narcissists . The cause of the crash was due to the age of the plane.


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(@D3SWI33)
Joined: 9 years ago

Posts: 1705

I toed a sew. I f:&;&n toed a sew.


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(@Alpha Golf)
Joined: 12 years ago

Posts: 171

Delta had seventeen MD-11s


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(@Ricardo)
Joined: 4 years ago

Posts: 11

Typo neart the start.
McDonell should be McDonnell.


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(@Steve S)
Joined: 8 years ago

Posts: 54

These images are borderline nauseating. Thankful we have them, of course, to help with the investigation but it must have been a horrific task for the pilots to try and understand what was going on behind them in a critical moment of flight
That said air travel is and will remain a completely safe endeavor considering the data. I am a little worried about Boeing and Agree with comments of 'hot mess'


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 John
(@John)
Joined: 9 years ago

Posts: 1034

Good Lord, both Tim Dunn and 1990 dispensing their turds of 'wisdom' in unison. Is there not enough suffering and mediocrity in the world??


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(@Eskimo)
Joined: 9 years ago

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Alter egos talking to each other (themselves).


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 John
(@John)
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TravelinPenis...if you allowed the "orange nazi baboon" to live rent-free inside your head 24/7, then your head must been contained not more than three and a half brain cells to begin with! Give politics a rest and live a little.


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(@Eskimo)
Joined: 9 years ago

Posts: 6145

OMG Tim "Fluffy" Dunn.

"DL and UA don't have planes with engines falling off" ?!?!?!?

CORRECTION
DL NW CO UA have ALL operated DC-10 aka. "planes with engines falling off"
Bonus for DL as they also trusted it so much they operated MD-11. The successor of "planes with engines falling off"
Yes that DL, Timmy. The successor was probably so premium only Delta Air Lines operated MD-11.

Just because engines didn't fall off under their livery doesn't mean "DL and UA don't have planes with engines falling off"


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Diamond
(@timtamtrak)
Joined: 5 years ago

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Getting a preliminary report is common within a few weeks of the accident. You also speculate yourself while asking others not to speculate. 😛


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Diamond
(@timtamtrak)
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The lift truck method was banned: https://drs.faa.gov/browse/excelExternalWindow/CEBF1F12352BF318862569F200688C4C.0001?modalOpened=true

“ (a) At each pylon removal and installation after the effective date of this AD, remove and install the engine and pylon separately unless removal or installation, or both, as an assembly is in accordance with a method approved by the Chief, Aircraft Engineering Division, FAA Western Region.”


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Diamond
(@timtamtrak)
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It’s worth noting that a few days ago, the FAA expanded the grounding to also include the DC-10, though there are only 8 airworthy examples registered in the US. (4 are owned by 10 Tanker Air for firefighting.)

https://avweb.com/aviation-news/dc-10-md-10-grounded-emergency-ad-md-11/


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Admin
(@lucky)
Joined: 13 years ago

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@ FlyerDon -- Yeah, as noted by Timtamtrak, preliminary reports are totally standard. The NTSB is simply sharing the facts that we have as of now (fatigue cracks aren't speculation, they're a fact), though we'll have to wait for the final report to know exactly what happened.


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(@FlyerDon)
Joined: 5 years ago

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What did I speculate about? Please give an example.


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Diamond
(@timtamtrak)
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Don, I was just writing a response to apologize. I initially misread that you were speaking as to this flight having flap asymmetry but your entire response other than about the NTSB prelim report was about AA191. My mistake, I’m sorry! I’d edit my original comment if I could but I’m happy to own the mistake.


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(@john_q_public)
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What exactly is his speculation...?


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(@FlyerDon)
Joined: 5 years ago

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Obviously I disagree with you. Preliminary reports are usually very basic. One or two releases and the NTSB departs the scene. It’s not like the MD11 is an ongoing problem. The planes are grounded and there is a pretty good chance they won’t be flying again anytime soon, if ever. A lot of infrequent flyers are seeing these videos, hearing about American’s accident from decades ago, and applying it to present day flying. The FAA/DOT are already making people nervous about flying, the NTSB doesn’t have to contribute to that. The next of kin and the employees of UPS also don’t need to keep seeing video of the accident every time they turn on the news.


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Admin
(@lucky)
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@ FlyerDon -- Filing a preliminary report within 30 days is the global standard for aviation, and isn't that level of transparency good? And I'd describe this report as being pretty basic -- it just covers the basics of the wreckage found, as is standard.

And the MD-11 *is* an ongoing problem or concern. The planes are grounded pending the outcome of the investigation. If the investigation reveals there's nothing wrong with the planes, then they'll presumably be flying once again.

It seems to me that investigation transparency should be prioritized over incorrect public perception of incidents. Like, we also hear every night on the news if there's another near miss, based on ATC audio. Does that mean ATC audio shouldn't be made public?

The way news is reported has changed over time, but I don't think that's a reason to withhold information.


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(@john_q_public)
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Why would you assume that these stress cracks could ONLY come from that specific procedure used in 1979??


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Diamond
(@tim-dunn)
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Posts: 7465

eskimo,
your typically low quality posts sink to a new low.

None of DL, NW, CO or UA had engines fall off of DC10 or MD11 aircraft.
AA did and came down to unapproved maintenance procedures.

The L10 simply had far fewer engineering or operational problems; doors blew open on multiple occasions on D10s on top of the UA D10 accident caused by an engine failure taking out the entire plane's hydraulic system.

Eastern was also a large L10 operator; DL just outlasted EA.

given that the AA incident was caused by damage to the pylon caused by an unapproved maintenance procedure and it was still used by a UPS contractor says a significant portion of the problem was about more than just the engineering of the plane.

but feel free to tell us about the 757 and 767 engines that have fallen off in flight - on any airline for any reason.


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(@Eskimo)
Joined: 9 years ago

Posts: 6145

Tim Tim Tim,

I keep forgetting reading comprehension isn't your strong point.
You can't sink lower than that.

Go read again.

And Tim, I don't know where you learn about current UPS procedures but they have banned the procedures used by AA191.

And read this again. And again. And again. Understanding anything isn't your strong point or even a skill for you.
And you probably still don't get it.
Because you're Tim Dunn.


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(@FlyerDon)
Joined: 5 years ago

Posts: 407

Not a problem. I went back and reread the -191 NTSB final report just for reference. The research and detail they went into was pretty amazing. I guess that’s why I don’t like the way they are handling this one. I’ve worked with them a few times and always found them to be very professional and somewhat reserved. I don’t know, maybe I’m just getting cranky.


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(@FlyerDon)
Joined: 5 years ago

Posts: 407

I agree, news gathering and reporting has changed greatly over the years but unless you work for UPS or Boeing, or you’re planning to buy an MD11, which I wouldn’t suggest doing, I think it’s prudent to let the investigators investigate and get the story off the front pages. In my view I think the lead investigator has gone way beyond a basic preliminary report and that has lead to endless speculation and I don’t think that is very beneficial to anyone. When the final report comes out in the next 12-18 months I look forward to your reporting on it. And I really mean that. In the meantime, if you have time, read some of the NTSB report on AA -191. I think you will be very impressed with the effort that went into finding the root causes of that horrible accident.


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(@Glidescope)
Joined: 2 years ago

Posts: 129

This is pretty concise and basic. In typical fashion for the NTSB, it does not jump to conclusions. However, when enough evidence can be gleaned from what they have seen so far, it's obvious that they have a pretty good idea of most of the basics and can make earlier and more directed recommendations. The MD-11F in this case has a LOT of cycles and flown hours, as expected of a freighter. Things like metal fatigue are well known but still not an exact science. While they are not making a final report yet until they can do their very thorough thing, I think that they have enough evidence so far that pretty much seals the MD-11F fate. Not worth it to wait 18+ months when you can draw a likely conclusion. The forces placed on the pylon at rotation are some of the most extreme it will experience, and also are at the worst possible time for fatigued metal to give way.

This does more of a service to their kin in knowing that the crew did all they could, and that future such incidents on this airframe can be prevented.


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(@AISI4130)
Joined: 9 months ago

Posts: 1

Stating the parting at the rear lug had fatigue fracture as a component of the rupture is a simple factual statement. Fatigue fractures are easily and reliably identified by visual examination. There is no causation statement as to why the fatigue initiated and advanced, which would be the sort of thing to avoid this early in an investigation. All that said, I am not sure why the public needs to hear this fact about the fracture unless it is to help everyone understand this was not pilot error.


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