A UPS plane has crashed on take off in Louisville KY.

[RANDLOVER]

IIRC the Kentucky governor said it was headed to Hawaii and carrying over a million litres of fuel, I didn't know they could carry so much. Unfortunately they suspect the three crew have been killed and at least two people are missing from an auto parts store, 11 people have been injured from the store and an adjacent oil recycling plant.

[BradC]

Looking at various news sources the plane was held back for a couple of hours for work/verification on #1. It then left #1 at the side of the runway during the takeoff roll and given the video it might appear bits of #1 got ingested into #2 which surged and failed. Apparently they were past decision point when the failure(s) occurred so they attempted to take off.

Pretty sad, but the DC-10/MD-11 didn't/doesn't have a great track record. My uncle in California was part of the team that designed the wing for the DC-10 and he point-blank refused to fly on them.

[V8Ian]

I don't think UPS are/were about to knock anyone down the safety leader board.

[Captain_Rightfoot]

UPS MD11 crashed near the Louisville airport - Page 3 - PPRuNe Forums (https://www.pprune.org/accidents-close-calls/669082-ups-md11-crashed-near-louisville-airport-3.html)


https://youtu.be/Z3lXl9yfISM?si=rJWvCT4eXCba__Rm

[Captain_Rightfoot]

IIRC the Kentucky governor said it was headed to Hawaii and carrying over a million litres of fuel, I didn't know they could carry so much. Unfortunately they suspect the three crew have been killed and at least two people are missing from an auto parts store, 11 people have been injured from the store and an adjacent oil recycling plant.

It didn't have that much fuel I can assure you .. max fuel capacity of a md11 is 146000 litres. It looked a lot like a million litres going up though. :(

[Captain_Rightfoot]

IIRC the Kentucky governor said it was headed to Hawaii and carrying over a million litres of fuel, I didn't know they could carry so much. Unfortunately they suspect the three crew have been killed and at least two people are missing from an auto parts store, 11 people have been injured from the store and an adjacent oil recycling plant.
Turns out they crashed into a fuel depot. :(

[RANDLOVER]

Turns out they crashed into a fuel depot. :(

Seems like a bad place to put a fuel depot.

[BradC]

It probably wasn't designed to have a plane land on it either.

[V8Ian]

It probably wasn't designed to have a plane land on it either.
Not even planned.

[Captain_Rightfoot]

Seems like a bad place to put a fuel depot.

Unfortunately these airports typically grow over the years. A quick click and it was built in 1941 by the military when planes were small and slow. It started as a single 1200m runway like the one I used to fly gliders from, and now it's massive.

[BradC]

Not even planned.

Clearly. Back in 2003 we helped design a new Airport Control Center for Dubai Airport. The concept was it had to survive an "unplanned landing" from a 747. It was mostly underground. When most of these airports were built they just were not designed for the structural load required to cope with todays jet propelled whales.

[Captain_Rightfoot]

https://www.youtube.com/live/PuoMok1ynF4?si=qh0sr5zusa5WpvTt


https://www.youtube.com/live/Rw6CtQJckzE?si=M154eNUSGV4MLuuy

[Captain_Rightfoot]

I think we can say that number 1 engine failed. They've found blades all down the runway. It then fell off and chose not to go flying.

I suspect they were just passengers heading to the scene of the crash after that.

I suspect the bulk of the investigation will be about how an engine failed so catastrophically that it sprayed bits everywhere which likely caused critical damage, and then fell off. The maintenance and past history of this AC is going to be the focus.

Engine failures happen on takeoff and they are supposed to stay contained and pilots are trained to go flying and sort it out later.


https://www.youtube.com/live/srB2ezbnP24?si=IYXgu2LnzdJq2KpG

[BradC]

From the various videos available it looks like when #1 failed it caused an issue with #2. Once #2 went there was no way back.

Not good.

[V8Ian]

Yes, it seems that #2 ingested parts of #1.
In the case of engine failure, the housing is supposed to contain all parts. That didn't happen in this case.

[Captain_Rightfoot]

I saw they think #2 was surging too. Looks like they were just passengers on the way to the scene of the accident. [bigsad]

[Tins]

As Juan points out, there have been pylon failures in the past. The engine thrust has to go somewhere. The engine can rotate up over the wing. The FOD the #2 engine ingested could easily have come from the remains of the pylon. In any case, if the #2 lost thrust all bets were off
They might reconsider siting a fuel recycling plant at the end of the runway.

[JDNSW]

A bit like the setup at Bourke something like sixty years ago.

Bourke railway station was the end of the line. And the fuel depot was literally, just beyond the station, at the end of the line, after a dead straight section of about 100 miles, with a slow speed limit, because it was a low grade track. It was a long, boring trip.

The engine driver and fireman both went to sleep - and woke up when the train went through the station without stopping, and struck several fuel wagons on the track in the depot.

They were not going very fast, but the wagons ruptured, spilling a large quantity of petrol, and there were enough sparks to ignite it. The fire spread to the main storage tanks at the depot. Apparently it was spectacular.

[Captain_Rightfoot]

As Juan points out, there have been pylon failures in the past. The engine thrust has to go somewhere. The engine can rotate up over the wing. The FOD the #2 engine ingested could easily have come from the remains of the pylon. In any case, if the #2 lost thrust all bets were off
They might reconsider siting a fuel recycling plant at the end of the runway.
If it was an engine failure leading to pylon separation you can bet there was some very very funky vibrations going on.


https://youtu.be/KhGw0V2mcNI?si=AS6yopPaYTWcrBhP

[Captain_Rightfoot]

https://youtu.be/uq3SmmMptx0?si=pKkPoJpdUUJ57BKD

[RANDLOVER]

UPS and FedEx have grounded their MD-11 planes as a precaution.

[Captain_Rightfoot]

UPS and FedEx have grounded their MD-11 planes as a precaution.
I saw that. I can imagine the crews would also be pretty keen on this. Answers are needed.

[BradC]

UPS and FedEx have grounded their MD-11 planes as a precaution.

Apparently at the recommendation of Boeing, and now by an emergency airworthiness directive from the FAA. Looks serious.

Dynamic Regulatory System (https://drs.faa.gov/browse/excelExternalWindow/DRSDOCID188588539020251108211920.0001)

[Tins]

https://youtu.be/FuhEWr8rmxY?si=cyj7S7MwoyZWu-2h

[Tins]

If it is eventually found that this was due to an engine failure then there’s no call to blame the aircraft. MD, Boeing, Airbus etc don’t make engines, and the carrier is responsible for maintenance.
The trijet design could have played a role of course. Maybe that’s one of the reasons we don’t see 727s anymore.

[BradC]

If this comes down to an uncontained engine failure then it's likely to ground a pile of 767 and 747-400s also.

[Tins]

If this comes down to an uncontained engine failure then it's likely to ground a pile of 767 and 747-400s also.

Yep. Remember the SouthWest incident? They got it down ok, minus one unfortunate woman. I know that was a 737, but rotorbursts don't discriminate.

[BradC]

They've grounded all MD11s regardless of engine type. They have a mix of GE & PW. The AD isn't constrained to the GE.

It's interesting there is no remedial action in the AD yet, so it's just a blanket "stop them flying" at the moment.

[Tins]

They've grounded all MD11s regardless of engine type. They have a mix of GE & PW. The AD isn't constrained to the GE.

It's interesting there is no remedial action in the AD yet, so it's just a blanket "stop them flying" at the moment.

Anyone could think it was a Concorde.

[Captain_Rightfoot]

Even though there hasn't been a lot released people on the inside will likely have a pretty good idea by now.

It does look like a massive uncontained engine failure that happened after V1. Once it took out number 2 they were doomed. :(

As noted above apparently that engine is used on quite a number of passenger 767 and some remaining 747400.

On PPRUNE there was some discussion that non standard parts are sometimes used. The maintenance history of number one is going to be gone trough big time.

[Tins]

On PPRUNE there was some discussion that non standard parts are sometimes used. The maintenance history of number one is going to be gone trough big time.

in 1996 Michael Crichton published his great book Airframe in which he discusses that very issue, including counterfeit parts.

[JDNSW]

The extension to all MD-11 regardless of engine is probably because it is unclear as to the cause of the pylon detaching. They may think it is due to engine failure, but are being cautious until they are certain of this. I expect to see a more specific directive, but that could take a while.

[Tins]

The extension to all MD-11 regardless of engine is probably because it is unclear as to the cause of the pylon detaching. They may think it is due to engine failure, but are being cautious until they are certain of this. I expect to see a more specific directive, but that could take a while.

Seems likely, given that it has happened before.
Poor old DC-10 MD-11 rep takes another big hit. Does the USAF still use the KC-10?

[JDNSW]

According to WIkipedia, not since September 2024.

[BradC]

including counterfeit parts.

GE have covered this before, looking at turbine discs with both original and "pattern" turbine blades and the significant differences between them.

[RANDLOVER]

There are huge forces involved IIRC I heard that in a jet engine it is equivalent to a locomotive hanging on a turbine blade.

[Captain_Rightfoot]

I do struggle with how you can have aftermarket turbine blades, but apparently it's a thing.

This is another video which has a good zoomed in shot as the AC staggers into the air. The amount of flames and sparks going over the wing it's hard to see how number 2 could not have been damaged. Clearly massive wing damage from the engine detachment.

If you watched the NTSB updates they had a bell sounding at 37 seconds, which they have also confirmed was after "rotate" command being given.


https://youtu.be/aPrV-k004F8?si=YHopsSwNfpjiEnFl

[Tins]

I do struggle with how you can have aftermarket turbine blades, but apparently it's a thing.



I don't struggle with the idea they exist, but I definitely have issues understanding why a major carrier would use them. That sort of cost cutting is a third world thing. Unfortunately for them. UPS has no need.

Of course, I'm not saying they actually did. Way to soon for that sort of speculation, but yes, it is a thing.

[Captain_Rightfoot]

Analysis of the grounding.


https://youtu.be/LYIKD_lfG74?si=wr6JWPtpRfLtmYx2

[Tins]

Analysis of the grounding.




Juan asks the right questions, imo. The FAA had to act, of course, but did they know it was an airframe failure, or did they assume? Seems to me that if there's any suspicion of the engines then perhaps they didn't go far enough. Bur we'll see, I guess.

[JDNSW]

I think they did not assume anything - but there is a suspicion that it could be an airframe failure, and that is enough.

On the other hand, don't forget that these are old aircraft, and they were not designed by nor built by the current holder of the certificate (Boeing), so, since the FAA will be heavily influenced by the holder of the certificate, and they in turn might just welcome the opportunity to drop support of this aircraft, and would not be unhappy if they were permanently grounded!

[Captain_Rightfoot]

I think they did not assume anything - but there is a suspicion that it could be an airframe failure, and that is enough.

On the other hand, don't forget that these are old aircraft, and they were not designed by nor built by the current holder of the certificate (Boeing), so, since the FAA will be heavily influenced by the holder of the certificate, and they in turn might just welcome the opportunity to drop support of this aircraft, and would not be unhappy if they were permanently grounded!

Ooops.. the md11 can never fly again. Can I interest you in a 767 Freighter?

[Tins]

No wonder we don't have a bloody clue what's really going on. OK, I know that most of us are aware of the rising tide of AI fakes, but...

https://youtu.be/Y6-9NmsJfRM?si=8RssyFYHKC-5Co3i

Oh yeah, it has a sponsored section...

[Captain_Rightfoot]

Right on rotation one engine fails and breaks off and takes out the second engine. :(

Or maybe the engine doesn't fail .. maybe it just breaks off. I'm told rotation is one of the highest centripetal loads on everything.




https://youtu.be/eoNETrBKzx8?si=qTpVGRYhs9uzj7ig

[BradC]

Prelim report :
https://leehamnews.com/wp-content/uploads/2025/11/Prelimiary-Report-DCA26MA024-UPS-MD11.pdf

[Captain_Rightfoot]

Prelim report :
https://leehamnews.com/wp-content/uploads/2025/11/Prelimiary-Report-DCA26MA024-UPS-MD11.pdf

Thanks. So looks like the pylon separating was the cause.. not an engine failure causing the pylon to fail.

Right on rotation. They were just passengers going to the scene of the crash. [bawl]

[BradC]

Yep. Looks like a structural failure. That explains why they grounded the entire type.

[JDNSW]

Yes, it was a structural failure, but was it initiated by :- design, maintenance design, maintenance practices*, or engine vibration outside design parameters.

My guess is the fatigue failure of the mount long predated this flight, which seems to exonerate the engine.


*see the DC-10 crash resulting from unauthorised practice of removing engine plus pylon instead of engine alone.

[Captain_Rightfoot]

Yes, it was a structural failure, but was it initiated by :- design, maintenance design, maintenance practices*, or engine vibration outside design parameters.

My guess is the fatigue failure of the mount long predated this flight, which seems to exonerate the engine.


*see the DC-10 crash resulting from unauthorised practice of removing engine plus pylon instead of engine alone.
The way the engine lifted suggests that the rear mount failed first. It just pulled itself up and then broke the front mount. That it took out the #2 on the way through.. so unlucky.

[BradC]

The way the engine lifted suggests that the rear mount failed first. It just pulled itself up and then broke the front mount. That it took out the #2 on the way through.. so unlucky.

The report basically says the aft mount failed :

"After initial cleaning of the fracture surfaces, examination of the left pylon aft mount lug
fractures found evidence of fatigue cracks in addition to areas of overstress failure. On the aft
lug, on both the inboard and outboard fracture surfaces, a fatigue crack was observed where
the aft lug bore met the aft lug forward face. For the forward lug's inboard fracture surface,
fatigue cracks were observed along the lug bore. For the forward lug's outboard fracture
surface, the fracture consisted entirely of overstress with no indications of fatigue cracking."

[Captain_Rightfoot]

The report basically says the aft mount failed :

"After initial cleaning of the fracture surfaces, examination of the left pylon aft mount lug
fractures found evidence of fatigue cracks in addition to areas of overstress failure. On the aft
lug, on both the inboard and outboard fracture surfaces, a fatigue crack was observed where
the aft lug bore met the aft lug forward face. For the forward lug's inboard fracture surface,
fatigue cracks were observed along the lug bore. For the forward lug's outboard fracture
surface, the fracture consisted entirely of overstress with no indications of fatigue cracking."



So good this analysis.


https://youtu.be/UpUkwzVUs5Y?si=vCY8eEr6AIDe4S9X

[JDNSW]

From what we have seen so far, this has to be one of the best documented aviation accidents ever - really good footage of the accident from multiple viewpoints, both recorders found and producing good data, lots of witnesses, accident site controlled immediately, and the key point on open but secure ground allowing rapid and skilful collection of data on the engine departure..

And from the rapid publication of the preliminary report, the NTSB is doing a good job of analysing the data. But because of the amount of data, I expect it will take a long time to get to the final report and decide what caused the fatigue cracks to appear before the next inspection was due. Always assuming the previous inspection was completed correctly, something that may take a good while to determine.

I assume that there will be inspections of the pylon mounts on all of these aircraft before they allow them to fly again, and it will be interesting to see if any fatigue cracks are detected. I assume inspections will be using a penetrant dye since the mounting lug that broke is non-magnetic.

[BradC]

The only thing that would make things easier is having a wreck to examine. The fire just complicates the investigation. At least most of the pylon left with the #1 engine so it can be accurately examined.

[JDNSW]

They seem to have recovered the brackets that the pylon was attached to from the wreckage and the bits that broke off, apparently from the pylon, both intact enough to see the fatigue cracks, which show up distinctively on the fracture surface (see the pictures in the video).

[Captain_Rightfoot]

From what we have seen so far, this has to be one of the best documented aviation accidents ever - really good footage of the accident from multiple viewpoints, both recorders found and producing good data, lots of witnesses, accident site controlled immediately, and the key point on open but secure ground allowing rapid and skilful collection of data on the engine departure..

And from the rapid publication of the preliminary report, the NTSB is doing a good job of analysing the data. But because of the amount of data, I expect it will take a long time to get to the final report and decide what caused the fatigue cracks to appear before the next inspection was due. Always assuming the previous inspection was completed correctly, something that may take a good while to determine.

I assume that there will be inspections of the pylon mounts on all of these aircraft before they allow them to fly again, and it will be interesting to see if any fatigue cracks are detected. I assume inspections will be using a penetrant dye since the mounting lug that broke is non-magnetic.
I think that the type is down to 82 examples might play into it. They will have more time to consider the issue, and the low volume of AC that are nearing retirement might affect the fix too. Hopefully will just be a change to inspection schedule but if it requires expensive changes then it might not be worth it in many cases.

[Tins]

I think that the type is down to 82 examples might play into it. They will have more time to consider the issue, and the low volume of AC that are nearing retirement might affect the fix too. Hopefully will just be a change to inspection schedule but if it requires expensive changes then it might not be worth it in many cases.

The number of hours and cycles the airframes have done will be a big influence as well. I'm certain that Boeing can come up with a new inspection schedule, but any modifications to the structure would probably tip the scales of a cost/benefit analysis. Not cheap to re-engineer and refit 82 of them.

Of course, foreign carriers can do their own thing, but the countries they can fly to will sure be restricted.

[Blknight.aus]

From what we have seen so far, this has to be one of the best documented aviation accidents ever - really good footage of the accident from multiple viewpoints, both recorders found and producing good data, lots of witnesses, accident site controlled immediately, and the key point on open but secure ground allowing rapid and skilful collection of data on the engine departure..

And from the rapid publication of the preliminary report, the NTSB is doing a good job of analysing the data. But because of the amount of data, I expect it will take a long time to get to the final report and decide what caused the fatigue cracks to appear before the next inspection was due. Always assuming the previous inspection was completed correctly, something that may take a good while to determine.

I assume that there will be inspections of the pylon mounts on all of these aircraft before they allow them to fly again, and it will be interesting to see if any fatigue cracks are detected. I assume inspections will be using a penetrant dye since the mounting lug that broke is non-magnetic.

Theres a type of induction testing that works with ally and alloys but IIRC it doesnt give a very precise result and is kind of a go/no go test to negate or approve the requirement for more expensive/invasive testing.

Whichever method they choose Id really love to see a 3d rendered model and some cutaways done that showcase the crack(S) through the depth of the pylon.

Id also be interested to see if a "ringing test" might have revealed anything. Effectively hang it from a bit of wire and tap it with a hammer, solid relaxed metals resonate differently to ones with internal stresses and fractures. Put a good one up next to a failed one and give them both a love touch with a suitable mallet..

[Tins]

Nevil Shute, author and aeronautical engineer, wrote about fatigue failures in structural alloys in 1948. One would hope they have moved on a little from then...

[JDNSW]

More precisely, Neville Shute Norway, when he was wearing his engineers hat.

He started his career as an aeronautical engineer after a brief stint at De Havilland, doing stress analysis on the Airship Guarantee Company's (Vickers) R100 airship in 1924-1929. The R100 was quite successful, and did a return trip across the Atlantic without significant incidents. However, its competitor, the R101, built by the British government, on its maiden flight to New Delhi, crashed in France with few survivors. This led to the grounding of R100, and it was scrapped shortly afterwards.

Norway then founded the Airspeed Ltd to build advanced civil aircraft and a few years later started producing the Airspeed Courier single engine retractable, and later the Envoy, a twin. Having picked a bad time to start (Great Depression), by 1940 the company was taken over by De Havilland, and produced a large number of the twin as the Oxford trainer for the RAF.

He thought that both Vickers and the directors of Airspeed would be less than thrilled by having him a published author (starting 1926), so he only used his first two names for his writing.

[Tins]

True, John, but I know him from his novels, although I have read Slide Rule several times. He was scathing of the Air Ministry's handling of the whole R101 project. He said that they cost those lives due to their bureaucratic bungling and interference.

I highly recommend Slide Rule to those who are interested. Brilliant autobiographic work written by a true story teller.

He has a street named after him in Berwick. I guess Lord Casey had something to do with that. Nevil loved Australia.

[Captain_Rightfoot]

https://youtu.be/q5OQzpilyag?si=0SAbbUimFUT7VVEp