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Air France A380 over Greenland on Sep 30th: Fan and engine inlet separated

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11–20 of 152 posts

Re: Air France A380 over Greenland on Sep 30th: Fan and engine inlet separated

#11
post #9

This screams of poor servicing.

It does? How can you conclude that without having inspected the missing parts?

It could be a manufacturing defect, it could be all kinds of other things including a design flaw, to conclude that it 'screams of bad servicing' without having any evidence on an incident that is not even a day old is jumping to conclusions.

Re: Air France A380 over Greenland on Sep 30th: Fan and engine inlet separated

#12

Seriously lucky that the disintegration didn't take out vital hydraulics or fuel systems in the wing, or penetrate the pressurised fuselage. I'd like to hope that this wasn't caused by ground crew error, i.e. an improperly secured cowling or access hatch, which snowballed into major component failure...

[deleted]

Re: Air France A380 over Greenland on Sep 30th: Fan and engine inlet separated

#13

Earlier quoted context omitted.

The A380 has two hydraulic systems. If the priamry fails, the aircraft is still fully flyable. Some extra things like slats don't work anymore but those aren't critical for flight and landing. If the secondary hydraulics fail, there are still extra electric actuators to move the control surfaces. Source: http://www.roger-wilco.net/wp-content/uploads/2010/11/Untitl...

I mean, primary and backup hydraulics are hopelessly intertwined on this systems diagram, certainly physically. Not sure how much that is going to help against parts flying into it. Which is of course what happened in that linked incident below: https://en.wikipedia.org/wiki/United_Airlines_Flight_232 The three hydraulic systems were separate, so that failure of any one of them would leave the crew with full control,…

IIRC there's valves to contain such failures at regular intervals. And the electrical backup system can then provide some power in the cutoff sections. I'd hope that airplane designers learned a thing or two since the DC-10 (and have some additional tools to play with).

Re: Air France A380 over Greenland on Sep 30th: Fan and engine inlet separated

#14

Earlier quoted context omitted.

The A380 has two hydraulic systems. If the priamry fails, the aircraft is still fully flyable. Some extra things like slats don't work anymore but those aren't critical for flight and landing. If the secondary hydraulics fail, there are still extra electric actuators to move the control surfaces. Source: http://www.roger-wilco.net/wp-content/uploads/2010/11/Untitl...

I mean, primary and backup hydraulics are hopelessly intertwined on this systems diagram, certainly physically. Not sure how much that is going to help against parts flying into it. Which is of course what happened in that linked incident below: https://en.wikipedia.org/wiki/United_Airlines_Flight_232 The three hydraulic systems were separate, so that failure of any one of them would leave the crew with full control,…

As your reference points out: "Newer aircraft designs such as the McDonnell Douglas MD-11 have incorporated hydraulic fuses to isolate a punctured section and prevent a total loss of hydraulic fluid."

A quick search for "A 380 hydraulic fuses" finds sources like http://www.airliners.net/forum/viewtopic.php?t=765509 :

> If one or both hydraulic systems fail, the following hydro-electrical backups remain available: For flight controls: The Electrical-Hydrostatic Actuators (EHAs) and the Electrical Backup Hydraulic Actuators (EBHAs) For braking and steering: The Local Electro-Hydraulic Generation System (LEHGS)"

That's depicted in the image bad_alloc showed.

And, "hopelessly intertwined"? Is that your viewpoint as a software developer, or are you an aircraft designer? Because I'm sure that an outsider would see my code as "hopelessly intertwined" even when it isn't.

Re: Air France A380 over Greenland on Sep 30th: Fan and engine inlet separated

#15
post #14

Earlier quoted context omitted.

I mean, primary and backup hydraulics are hopelessly intertwined on this systems diagram, certainly physically. Not sure how much that is going to help against parts flying into it. Which is of course what happened in that linked incident below: https://en.wikipedia.org/wiki/United_Airlines_Flight_232 The three hydraulic systems were separate, so that failure of any one of them would leave the crew with full control,…

As your reference points out: "Newer aircraft designs such as the McDonnell Douglas MD-11 have incorporated hydraulic fuses to isolate a punctured section and prevent a total loss of hydraulic fluid." A quick search for "A 380 hydraulic fuses" finds sources like http://www.airliners.net/forum/viewtopic.php?t=765509 : > If one or both hydraulic systems fail, the following hydro-electrical backups remain available: For…

"Because I'm sure that an outsider would see my code as "hopelessly intertwined" "

That depends. Do you use the object oriented programming model? LOL

Re: Air France A380 over Greenland on Sep 30th: Fan and engine inlet separated

#16
post #2

It's more than just fan blade failure. Engines are tested against fan blade failures. The surrounding cowling should contain it. In this case the whole fan disk is gone. Uncontained failure like this can down the plane depending on the where the parts fly.

Maybe the cowling did contain the disk failure, it just didn't stay attached to the rest of the engine afterwards.

Re: Air France A380 over Greenland on Sep 30th: Fan and engine inlet separated

#17
Lucky break that didn't happen over a city, that's some pretty serious aircraft droppings and if they had fallen onto a market or a highway hear the point of departure (or anywhere else, but typically aircraft are only overflying cities near airports) it would have been very ugly.

Re: Air France A380 over Greenland on Sep 30th: Fan and engine inlet separated

#18

Sounds like it was over water, meaning they won't be able to retrieve the fan to determine why it failed.

There's some suggestion that it was over Greenland: https://twitter.com/flightradar24/status/914197103026622464.

Re: Air France A380 over Greenland on Sep 30th: Fan and engine inlet separated

#20
post #16
post #2

It's more than just fan blade failure. Engines are tested against fan blade failures. The surrounding cowling should contain it. In this case the whole fan disk is gone. Uncontained failure like this can down the plane depending on the where the parts fly.

Maybe the cowling did contain the disk failure, it just didn't stay attached to the rest of the engine afterwards.

I'm with you on the cowling containing the failure, there is no other explanation why the cowling would disappear as one piece, the amount of force required to shear that module off the front of the engine is substantial. I really hope they will be able to recover the part but I fear we will never know which is going to make puzzling out how this could have happened extremely hard. Though the people working on these cases never fail to impress with their ability to retrieve the story from a pile of fragments you need to those fragments to begin with and the most important bits are missing here.
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