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

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

#101

Post by dredmorbius »

JumpCrisscross wrote: post #86
gmueckl wrote: post #85

Earlier quoted context omitted.

As far as I have picked up on that subject, passenger aircraft have multiple layers of protection against blades separating from the engine. The cowling is supposed to contain it. If that does not work, the fuselage in the area of the wings is hardened to prevent the separating part(s) from entering the passenger compartment and doing damage there. This is typically implemented using a Kevlar lining on the hull. The…

Keep in mind that the Quantas failure, while horrible, resulted in zero fatalities.

Whislt technically correct (the best kind), attributing this to adequate engineering given scope of damage is difficult. I've reviewed this incident myself several times -- not a statement of my qualifications (nil), only familiarity -- and tremendous credit must be given the flight crew which included the presence of a check team (there were five pilots in the cockpit).

One engine failed completely, two others were seriously degraded, aircraft control was minimal, fuel could not be dumped (leading to an overweight laading). The impression from one documentary was that the first officer spent much of his time overwhelmed with system reports which had to be cleared from his displays. Systems and information design and flows seem a net negative for this incident -- there is such a thing as too much information.

Overall, many reserve margins were exceedingly tight.

Your comment seems to me to grossly understate the severity, and overly credit Airbus and Rolls Royce, in this case

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

#102

Post by jaclaz »

leoc wrote: post #100
katastic wrote: post #79

Earlier quoted context omitted.

According to this: https://en.wikipedia.org/wiki/Gliding_flight#Aircraft_.28.22... The 747-200 also has a glide ratio of 15:1. I can't tell if that's amazing, good, or average. A sailplane can have up to 60:1! That's pretty impressive! According to this: A "clean A320" has 17:1. Neat. https://aviation.stackexchange.com/questions/14814/could-a-c... Something I never knew was this: >As someone said above, you have to r…

Obligatory Gimli Glider: https://www.damninteresting.com/the-gimli-glider/ http://www.gimlicommunityweb.com/history/gimli_glider.php .

Also (older accident):

https://en.wikipedia.org/wiki/British_Airways_Flight_9

>Ladies and gentlemen, this is your captain speaking. We have a small problem. All four engines have stopped. We are doing our damnedest to get them going again. I trust you are not in too much distress.

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

#103

Post by ghaff »

CydeWeys wrote: post #52
myth_buster wrote: post #32

Are there any serious dangers of debris falling over settlements in scenarios like these?

There's thousands of other more dangerous things you should worry about in your daily life. Like lightning or shark attacks. Now on the other hand, you could be taken out by an entire airplane crashing, e.g. https://en.wikipedia.org/wiki/American_Airlines_Flight_587

People on the ground were also killed as a result of the Pan Am Lockerbie bombing.

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

#104

Post by inferiorhuman »

eesmith wrote: post #88
inferiorhuman wrote: post #46

Earlier quoted context omitted.

> 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. Even with modern aircraft, even with the A380, when a fan lets go or the engine grenades bad things happen. Qantas Flight 32, an A380, suffered a UCE and everyone was very lucky that there were additional,…

Sure. But do all those correct statements mean that the A380 hydraulic control systems, and their backups, are "hopelessly intertwined" to an aircraft designer?

> Sure. But do all those correct statements mean that the A380 hydraulic control systems, and their backups, are "hopelessly intertwined" to an aircraft designer?

I'd hope so, given that all the redundancy didn't prevent an engine control failure on the A380.

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

#106

Post by lb1lf »

WalterBright wrote: post #60
CydeWeys wrote: post #51

Earlier quoted context omitted.

The A380 has four engines in total, and can easily tolerate the loss of just one in normal flight. Adding more engines has been a basic way to increase reliability since the beginning of the field; it's not just modern aircraft engineering. There's no other part of the airplane behind the engines either, so nothing to be hit by debris. What amazes me more is that the newest twinjets are now considered reliable enough…

> There's no other part of the airplane behind the engines either, so nothing to be hit by debris. The fans spin very fast, and will fly out radially, not just fall back. They'll slice right through anything they contact. The Airbus flight was very, very lucky.

Speaking of flying out radially, at least here in Norway, commercial prop planes had a broad red line painted on the interior cabin wall where prop blades would come knocking in case they were somehow torn from the hub.

I have never heard of an incident where prop debris penetrated the cabin, but avoided the seats on that row if at all possible, just in case.

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

#107

Post by Narishma »

BrandoElFollito wrote: post #90

There were questions in the article and one close over here, but no answer AFAIK : how did the move people from one plane to another if they could not desimbark them in the first place? Is the a way to connect two A380s together? (wild guess)

They transfered them to two smaller planes, not to another A380.

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

#108

Post by tyw »

KGIII wrote: post #94
katastic wrote: post #79

Earlier quoted context omitted.

According to this: https://en.wikipedia.org/wiki/Gliding_flight#Aircraft_.28.22... The 747-200 also has a glide ratio of 15:1. I can't tell if that's amazing, good, or average. A sailplane can have up to 60:1! That's pretty impressive! According to this: A "clean A320" has 17:1. Neat. https://aviation.stackexchange.com/questions/14814/could-a-c... Something I never knew was this: >As someone said above, you have to r…

You descend at just about the stall speed. It's pretty close to the slowest the individual plane can go before losing lift. I believe the term for coming in with no lift, purely gliding, is called dead stick. A Cessna 172 is worse, for comparison. I believe they are just 9:1. I guess it improves if you stop the prop entirely. I assume it is less drag.

best glide (converting altitude into the maximum distance) speed is quite a bit higher than the stall speed and found at the lift/drag max. minimum sink (converting altitude into the maximum time) is usually found about halfway between best glide speed and stall speed.

http://learntoflylv.com/drag%20curve.gif

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

#110

Post by mannykannot »

WalterBright wrote: post #60
CydeWeys wrote: post #51

Earlier quoted context omitted.

The A380 has four engines in total, and can easily tolerate the loss of just one in normal flight. Adding more engines has been a basic way to increase reliability since the beginning of the field; it's not just modern aircraft engineering. There's no other part of the airplane behind the engines either, so nothing to be hit by debris. What amazes me more is that the newest twinjets are now considered reliable enough…

> There's no other part of the airplane behind the engines either, so nothing to be hit by debris. The fans spin very fast, and will fly out radially, not just fall back. They'll slice right through anything they contact. The Airbus flight was very, very lucky.

You are assuming the blades separated from the hub. If the fan separated as a unit (someone suggested the shaft may have failed), I would guess it would go forwards.

Update: in 1981, the fan of the rear engine on an L-1011 separated, and chewed its way through the inlet duct ("The 'S' duct was damaged internally from next to the fan blades forward about 16 feet") before exiting the fuselage sideways, sending shrapnel into a lavatory and doing serious damage to the flight controls: "The displacement of the fan module in the course of the engine failure sequence caused loss of hydraulic systems A, B, and D and jammed the captain's and first officer's rudder pedals in the neutral position."

The aircraft landed safely, but with a little more damage, the airplane would have been uncontrollable.

https://www.faa.gov/about/initiatives/maintenance_hf/library...

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