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UPS plane crashes near Louisville airport

avherald.com

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Re: UPS plane crashes near Louisville airport

#121

Post by ExoticPearTree »

panxyh wrote: post #78
FabHK wrote: post #68

Earlier quoted context omitted.

V1 is the speed at which you can still stop the plane before the end of the runway. (It is computed for each takeoff based on runway length, aircraft mass, takeoff engine power setting, flaps, wind, runway condition, etc.) When the plane reaches V1, pilots take the hand off the throttle: they're committed to takeoff, even if an engine fails. It is better to take off and fix the problem or land again, than to smash in…

Isn't there any margin? Does it calculate stopping before end of runway or before causing damage? Surely uncertainty about the situation contributes to defaulting to committing, but what if it's a passenger plane and at V1 pilots know they've lost power? Wouldn't veering into highway at 30 mph be weighted against certain, big loss of life? Edit: I now see that this has been partially answered by uncle comment

After you reach V1, you take off.

Between V1, Rotate and V2, there’s like a 2-3kts difference (between each of them).

I am not familiar what the procedure is if you have dual-engine failure at or above V1.

Re: UPS plane crashes near Louisville airport

#122

Post by giantrobot »

loeg wrote: post #69
octaane wrote: post #40

Earlier quoted context omitted.

Agreed, only the NTSB investigation will provide a full account. But if you look at where they were on the runway, they had passed V1.

Yes, but multiengine aircraft are designed to take off with one lost engine.

There was more of an issue than just an engine being out. It looks like catastrophic damage to at least the left wing. So you have to now assume an engine out, reduced lift (if not a stall) on one wing, and likely no control surfaces responding on that wing.

Re: UPS plane crashes near Louisville airport

#123

Post by Hendrikto »

cjrp wrote: post #106

The AVHerald is usually the best source for these things, rather than MSM: https://avherald.com/h?article=52f5748f&opt=0 > Ground observers reported the aircraft had been delayed for about two hours for work on the left hand engine (engine #1), the engine #1 separated during the takeoff run, the center engine emitted streaks of flames, the aircraft impacted a UPS warehouse and ploughed through other facilities before…

https://archive.is/cdKm0

My IP was blocked, for some reason.

Re: UPS plane crashes near Louisville airport

#124

Post by HPsquared »

ragazzina wrote: post #120
filleduchaos wrote: post #83

Earlier quoted context omitted.

Well, there's a very big difference between "Engine fire: some of the combustion chamber's heat and flame has breached containment" and, say, "Engine fire: the engine has exploded, catastrophically damaging your wing which is now visibly on fire". However, both things are reported in the cockpit as ENG FIRE. There's also a very big difference between "Engine failure: something has damaged or jammed enough components…

> There's also a very big difference between "Engine failure: something has damaged or jammed enough components that the turbines are no longer spinning fast enough to produce thrust or drive the generators" and "Engine failure: the engine is no longer attached to the aircraft, which is why it is no longer producing thrust". However, both things are reported in the cockpit as ENG FAIL. What is the difference?

Wider effects like damage to the wing or changes to aerodynamics.

Edit: and damage to other engines, possibly engine #2 in the tail ingesting debris in this instance.

Re: UPS plane crashes near Louisville airport

#125

Post by mrb »

cjrp wrote: post #106

The AVHerald is usually the best source for these things, rather than MSM: https://avherald.com/h?article=52f5748f&opt=0 > Ground observers reported the aircraft had been delayed for about two hours for work on the left hand engine (engine #1), the engine #1 separated during the takeoff run, the center engine emitted streaks of flames, the aircraft impacted a UPS warehouse and ploughed through other facilities before…

Oh woah, very insightful discussion thread you found there.

So the tl'dr is: the leading very preliminary theory is that the MD-11's left engine fell off the wing just like https://en.wikipedia.org/wiki/American_Airlines_Flight_191 (a DC-10, the immediate predecessor of the MD-11) which was caused by maintenance errors weakening the pylon structure holding the engine.

Re: UPS plane crashes near Louisville airport

#126

Post by HPsquared »

avalys wrote: post #12
Jtsummers wrote: post #6

Earlier quoted context omitted.

> And at least in theory the MD-11 should be flyable with just two engines Flying with two engines and taking off without an engine in a loaded aircraft are two very different things. A lot more thrust is needed during takeoff than after.

Every multi-engine airliner is designed to be able to take off safely even if an engine fails at a critical moment. What might have happened in this case is that the mechanism of failure of one engine caused damaged or interfered with the operation of another engine (via smoke, debris, etc.), and taking off with two engines degraded is not part of the design criteria.

Some engine failures can't be contained within the cowling, like turbine disc rupture. Probably something like this happened where fragments punctured the surrounding wing structure and/or fuel tanks.

Re: UPS plane crashes near Louisville airport

#127

Post by rob74 »

mrb wrote: post #125
cjrp wrote: post #106

The AVHerald is usually the best source for these things, rather than MSM: https://avherald.com/h?article=52f5748f&opt=0 > Ground observers reported the aircraft had been delayed for about two hours for work on the left hand engine (engine #1), the engine #1 separated during the takeoff run, the center engine emitted streaks of flames, the aircraft impacted a UPS warehouse and ploughed through other facilities before…

Oh woah, very insightful discussion thread you found there. So the tl'dr is: the leading very preliminary theory is that the MD-11's left engine fell off the wing just like https://en.wikipedia.org/wiki/American_Airlines_Flight_191 (a DC-10, the immediate predecessor of the MD-11) which was caused by maintenance errors weakening the pylon structure holding the engine.

This video from an aviation youtuber contains a picture of the engine: https://www.youtube.com/watch?v=U4q2ORhIQQc&t=526s (the video itself is also worth watching in full IMHO).

What strikes me as odd is that this looks like the "naked" engine, without the cowling/nacelle that usually surrounds it? Anyway, if an engine departs the aircraft shortly after (last-minute) maintenance was performed on it, that's indeed suspicious...

Re: UPS plane crashes near Louisville airport

#128

Post by fredoralive »

zuppy wrote: post #117
eternityforest wrote: post #98

Earlier quoted context omitted.

Could they add cameras to solve this issue?

They surely can and this has been done. On one the flights that I took with Turkish Airlines they had a few video streams from different sides of the airplane. One was from the top of the tail and you could see the entire plane. Now... not sure how much that is helpful in this kind of emergency, they really didn't have time to do much.

I'm not sure they usually have the views on screen in the cockpit in flight, even if available (and an old MD-11 freighter won't have the cameras in the first place). The picture of an A380 cockpit (on the ground) on Wikipedia does show the tail view on a screen, but its on the screen normally used for main instruments. With an A380 that had an uncontained engine failure causing various bits of havok (Qantas 32?) IIRC the passengers could see a fuel leak on the in flight entertainment screens, but they had to tell the crew as AFAIK they didn't have access to the view in the cockpit in flight.

Re: UPS plane crashes near Louisville airport

#129

Post by ChrisMarshallNY »

I didn’t realize the MD-11 was still in use. It has had a difficult time in passenger aviation.

Looks really nasty. It seems to have come down in an industrial area, which will significantly reduce casualties. I can’t even imagine this, in a residential area.

Re: UPS plane crashes near Louisville airport

#130

Post by ChrisMarshallNY »

JCM9 wrote: post #108
justsid wrote: post #4

Earlier quoted context omitted.

The damage on the ground is scary to look at. I think the only silver lining here is that it was "just" a sparser industrial area and there weren't any homes. I'm really curious about what the investigation will reveal in a few months. This doesn't look like a "regular" engine fire from a bird strike or so, you would normally expect the flames to come out the back and not over the wing. And at least in theory the MD-…

Zoning guidance generally prohibits land use near an airport that has a high density of people, precisely to limit casualties during an event like this. Industrial would be permitted while residential and commercial use is not. Scarily there are communities that have ignored such logic and permitted dense residential development right next to an airport.

> Zoning guidance generally prohibits land use near an airport that has a high density of people

Queens, NY has entered the chat…

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