SDF UPS down

luvflyin said:
I’m wondering how many, if any, other planes have the same engine. It is looking like the engine is what started this. I’d think an AD should be out on the engine.
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The MD-11 had a CF6-80C2. The CF6 has a long history, with several growths in it, dating back to the TF39 (C-5 Galaxy engine) from which it was developed. The original CF6-6 was on the first DC-10s, and the -50 was the first growth model that also went on DC-10s as well as 747s and others. The -80 series I believe at this point is out of production, unless its military variant (which was ultimately used to re-engine C-5s) is still going. I'm not sure there.

The CF6 engine family has an extremely long history and, when I was at GE, was considered by many to be the best engine we'd ever produced, or at least certain parts of it. There have been some notable failures of it, for example UAL 232, but it overall has a very good history. There are many airplanes that have had these engines and are still in service with them. At this point, I would say most are probably 767s and A330s, given that there aren't many 747s out there anymore.

It's important to note that when I mention a "growth model", this isn't simply turning up the fuel to get more power on it at higher temperatures, or something where you're trying to get more out of the same construction like what we see in piston engines. Airlines need durability and time on wing, and if you just turn up the fuel and temps you reduce both of those numbers. There are notable changes, generally to include some combination of the diameter of the fan, compressor/turbine construction, etc. But, there are shared components to some extent and they normally fit within roughly the same envelope, although obviously items like fan diameter will have other external changes to cowlings, etc. If anything, sometimes you end up finding a bigger engine variant gets a derated thrust to then increase time on wing.

There are exceptions, for example the CF34s that I worked. If you look at the original CF34-1 (and then -3), which was/is on the Challenger 600 series and then the CRJ-100 and -200, that was a civilian derivative of the TF34. The later CF34-8 (CRJ-700/900 and E170/175 engine) shares effectively nothing in common with the -3 and then the -10 (E190/195 and ARJ-121 engine) shares yet again effectively nothing with the -3 and the -8. If you had schematics of those three variants on a table next to one another, you wouldn't be able to say at all "Oh, these engines are clearly part of the same family." You'd probably think the opposite.
 
Ted said:
The MD-11 had a CF6-80C2. The CF6 has a long history, with several growths in it, dating back to the TF39 (C-5 Galaxy engine) from which it was developed. The original CF6-6 was on the first DC-10s, and the -50 was the first growth model that also went on DC-10s as well as 747s and others. The -80 series I believe at this point is out of production, unless its military variant (which was ultimately used to re-engine C-5s) is still going. I'm not sure there.

The CF6 engine family has an extremely long history and, when I was at GE, was considered by many to be the best engine we'd ever produced, or at least certain parts of it. There have been some notable failures of it, for example UAL 232, but it overall has a very good history. There are many airplanes that have had these engines and are still in service with them. At this point, I would say most are probably 767s and A330s, given that there aren't many 747s out there anymore.

It's important to note that when I mention a "growth model", this isn't simply turning up the fuel to get more power on it at higher temperatures, or something where you're trying to get more out of the same construction like what we see in piston engines. Airlines need durability and time on wing, and if you just turn up the fuel and temps you reduce both of those numbers. There are notable changes, generally to include some combination of the diameter of the fan, compressor/turbine construction, etc. But, there are shared components to some extent and they normally fit within roughly the same envelope, although obviously items like fan diameter will have other external changes to cowlings, etc. If anything, sometimes you end up finding a bigger engine variant gets a derated thrust to then increase time on wing.

There are exceptions, for example the CF34s that I worked. If you look at the original CF34-1 (and then -3), which was/is on the Challenger 600 series and then the CRJ-100 and -200, that was a civilian derivative of the TF34. The later CF34-8 (CRJ-700/900 and E170/175 engine) shares effectively nothing in common with the -3 and then the -10 (E190/195 and ARJ-121 engine) shares yet again effectively nothing with the -3 and the -8. If you had schematics of those three variants on a table next to one another, you wouldn't be able to say at all "Oh, these engines are clearly part of the same family." You'd probably think the opposite.
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Thanks for putting in the time to get that detail.
 
Anybody know the context of this pylon crack photo? It's making the rounds as recently found on an MD-11 (10?).

images.jpeg
 
Hengelo said:
Anybody know the context of this pylon crack photo? It's making the rounds as recently found on an MD-11 (10?).

View attachment 147288
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I've seen that photo floating around several forums and social media sites, all claiming to be a cracked pylon found on another DC-10/MD-11, but nothing attributable. I've also see other "experts" claiming that is NOT an engine pylon and debunking it.
 
midwestpa24 said:
I've seen that photo floating around several forums and social media sites, all claiming to be a cracked pylon found on another DC-10/MD-11, but nothing attributable. I've also see other "experts" claiming that is NOT an engine pylon and debunking it.
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A number of people have presented maintenance drawings of the pylon structures and attach points and the object in that photo doesn't appear to match anything in those drawings.
 
Probably more of the AI generated images we’ve seen about this accident.
 
Pilot99B said:
I am having a hard time understanding how the left engine ended up on top in image number 3.
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There's a lot of inertia in the engine components and it doesn't immediately stop producing thrust as it comes apart. The engine pivots as the structural attachment to the wing fails, such that its thrust vector is pointing downward. Where else would you expect it to go but up?
 
Basically, the number one engine did not fail in any way, the structure that attached it to the wing fractured and allowed it to rotate as seen in the images. The power of the engine then ripped it the rest of the way off the wing and failures cascaded from there.
 
AV8R_87 said:
Prelim is out:

Page not found

www.ntsb.gov www.ntsb.gov

Fatigue cracks in pylon aft mounting lugs.
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Did the spherical bearing fail causing fatigue cracks in 3 of the four legs, leading to the overstress fail of the remaining lug? Did NTSB clean the bearing to take pictures. I don't see grease from what I assume are holes for grease to penetrate.
 
So very similar sequence to the AA191 ORD crash, although a different root cause. Metal fatigue versus maintenance induced damage.
 
Matthew said:
Wow. They had no chance.
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Why do you say that?

There is something missing between what we know and what happened. The airplane is capable of climbing out safely after an engine fails, catches fire, and/or departs. The two remaining engines have sufficient thrust to meet all of the climb requirements. This airplane did not climb as it should have and we don't yet know why. It was under control until the left wing hit a utility pole which started the unarrested roll to the left.
 
kyleb said:
Fair enough and reasonable. I figure it is about 50/50 pylon vs engine, but I guess we're gonna have to wait for more info from the NTSB to satisfy our curiosity...
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Prelim is out. Looks like 100% pylon. My suspicions about the engine somehow starting the sequence of events is pretty much debunked
 
Larry in TN said:
Why do you say that?

There is something missing between what we know and what happened. The airplane is capable of climbing out safely after an engine fails, catches fire, and/or departs. The two remaining engines have sufficient thrust to meet all of the climb requirements. This airplane did not climb as it should have and we don't yet know why. It was under control until the left wing hit a utility pole which started the unarrested roll to the left.
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There is video that shows a fireball coming from the #2 engine in the tail, telltale of a compressor stall and probable loss of thrust. A heavy MD-11 won't fly on one engine.
 
Larry in TN said:
Why do you say that?

There is something missing between what we know and what happened. The airplane is capable of climbing out safely after an engine fails, catches fire, and/or departs. The two remaining engines have sufficient thrust to meet all of the climb requirements. This airplane did not climb as it should have and we don't yet know why. It was under control until the left wing hit a utility pole which started the unarrested roll to the left.
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I didn’t know an engine departure was a designed in capability, but I assume that doesn’t include any structural or control damage from that occurrence. The left wing dips pretty heavily in the last couple of pix.
 
Larry in TN said:
Why do you say that?

There is something missing between what we know and what happened. The airplane is capable of climbing out safely after an engine fails, catches fire, and/or departs. The two remaining engines have sufficient thrust to meet all of the climb requirements. This airplane did not climb as it should have and we don't yet know why. It was under control until the left wing hit a utility pole which started the unarrested roll to the left.
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Under directional control, but not climbing at all. Contrary to earlier reports, the prelim says they never got more than maybe 100' AGL and possibly not even that high. We are obviously waiting for further details on the extent of the impact to the number 2 engine, but the prelim photos appear to confirm that the engine was experiencing either a compressor stall or being FOD'd out. That flame behind the left winglet in photo 6 is coming from the tail engine.

I acknowledge I'm making an assumption here, but at this point, I think it's fairly safe assumption that they did not have 2 good engines to fly out on. It's certainly no worse of an assumption than to assume they still had two good engines remaining.

I believe (and the photos seem to indicate) they fought like hell in a no-win situation.
 
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midwestpa24 said:
There is video that shows a fireball coming from the #2 engine in the tail, telltale of a compressor stall and probable loss of thrust. A heavy MD-11 won't fly on one engine.
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Maybe, but we don't know that yet. I didn't see anything in the preliminary report regarding the performance of the other two engines.

Matthew said:
I didn’t know an engine departure was a designed in capability, but I assume that doesn’t include any structural or control damage from that occurrence. The left wing dips pretty heavily in the last couple of pix.
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Less drag and weight if the engine is no longer attached. If anything that would improve performance. The pylon is designed to fail in a controlled manner to facilitate the engine's departure without undue damage. What actual damage occurred is yet to be determined.

What we do know is that they were not able to meet the engine-out climb gradient. We don't yet know why.
 
Matthew said:
I didn’t know an engine departure was a designed in capability, but I assume that doesn’t include any structural or control damage from that occurrence. The left wing dips pretty heavily in the last couple of pix.
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The left wing dips, but by frame 6, the FO had corrected the yaw and at least partially picked up the left wing.
 
Not a heavy pilot, but I was wondering the opposite. Why didn't they cut power and let it settle back to the ground? They were only a few feet off the ground when the engine departed.
 
Ed Haywood said:
Not a heavy pilot, but I was wondering the opposite. Why didn't they cut power and let it settle back to the ground? They were only a few feet off the ground when the engine departed.
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We spend our entire careers training the go/no-go decision at V1. Even if they knew the seriousness of what just happened (doubtful), it'd go against years if not decades of training to attempt to put the plane back on the ground at that point.
 
Ed Haywood said:
Not a heavy pilot, but I was wondering the opposite. Why didn't they cut power and let it settle back to the ground? They were only a few feet off the ground when the engine departed.
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Because they didn't have the time to react to the #2 engine betraying them too. At liftoff when the #2 started to appreciably eat trash, that behemoth was going to fireball at the UPS warehouse Jeju Air style, if they did what you suggest. Reality is I would have made the same go-decision as they did. They were already commited, given their situational awareness circumstances, for reasons @kayoh190 already highlighted.

The only other reason a transport crew would make the decision to run off the runway at high speed, is if they couldn't effect aerodynamic (pitch most often) control of the aircraft, like the rotation (elevator jackscrew) failures MD-80 pilots had to endure in past incidents, or stupid pilot tricks like control lock takeoffs. As outlier a situation as that is, this crew had full control authority to rotate and liftoff the aircraft. So they 100% made the decision their training directed with the information they had. Which again, was much less than what we have sitting here at 1G/0kts of course.

They were screwed. Having the meat of the accident sequence occur at literal liftoff was not a death sentence... losing the #2 engine as late in the sequence as they did, was. And my username checks.
 
hindsight2020 said:
Because they didn't have the time to react to the #2 engine betraying them too. At liftoff when the #2 started to appreciably eat trash, that behemoth was going to fireball at the UPS warehouse Jeju Air style, if they did what you suggest. Reality is I would have made the same go-decision as they did. They were already commited, given their situational awareness circumstances, for reasons @kayoh190 already highlighted.

The only other reason a transport crew would make the decision to run off the runway at high speed, is if they couldn't effect aerodynamic (pitch most often) control of the aircraft, like the rotation (elevator jackscrew) failures MD-80 pilots had to endure in past incidents, or stupid pilot tricks like control lock takeoffs. As outlier a situation as that is, this crew had full control authority to rotate and liftoff the aircraft. So they 100% made the decision their training directed with the information they had. Which again, was much less than what we have sitting here at 1G/0kts of course.

They were screwed. Having the meat of the accident sequence occur at literal liftoff was not a death sentence... losing the #2 engine as late in the sequence as they did, was. And my username checks.
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Exactly it. This wasn't a V1 cut type of incident, they were past VR and flying. No one trains to abort in a jet at that point. You take it in the air and deal with the emergency there. The result would have been the same if they did slam it back on the runway, except they maybe wouldn't have travelled as far. In the seconds from the engine departing to the crash, the crew would have had no way to assess what was really happening and act on it anyway. The aircraft failed them in a manner that there was no possible happy ending.
 
My take on it is that #2 had to be ingesting super-heated air from the fire where #1 was which would have derated it's thrust. Even at idle several jet engines have ingested people and equipment now at take-off power think of how much air that engine is pulling in. Plus, it may have eaten some FOD from #1 departure.
 
Plano Pilot said:
My take on it is that #2 had to be ingesting super-heated air from the fire where #1 was which would have derated it's thrust. Even at idle several jet engines have ingested people and equipment now at take-off power think of how much air that engine is pulling in. Plus, it may have eaten some FOD from #1 departure.
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It's not 100% apparent just from the pictures, but if you read the report they do say that the #1 engine went up and over the fuselage, so whatever fire and metal #1 was shedding as it flew away had a high probability of being sucked right into #2.

They don't say anything about reduced thrust on #2, but they do say that the radar altimeter (per the FDR) never got higher than 30 feet AGL. And they do reference the AAL191 crash and how that plane made it to 325 AGL.
 
midwestpa24 said:
So very similar sequence to the AA191 ORD crash, although a different root cause. Metal fatigue versus maintenance induced damage.
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It actually reminds me of Alaska Air 261 in terms of potential root cause. In both cases, regular maintenance/inspection was deferred under an operator scheduled maintenance program. Six years to inspect that bearing, which by my take of the numbers looks like was original to the aircraft. I wonder how someone came up with those numbers, and whether it was extrapolated data, a guess, or something else.

In a very dark humor way, it reminds me of the story of how to tighten the cylinder heads on a Porsche - you tighten then until something cracks, then you back off a half turn. In this case, you keep extending the maintenance windows by 200% until someone doesn't make it. Perhaps too harsh for this one, but not harsh enough for 261.
 
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