Qantas A380 uncontained #2 engine failure
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FDR
If you are concerned about the hydraulics and flight controls, the A380 flies fine with both hydraulic systems failed. Instead of a third hydraulic system for flight control redundancy, there are electrically powered actuators and electrical / hydraulic actuators to power the flight controls as well as standard actuators.
That is simplifying it, but there has been no sacrificing of redundancy.
N
(edited to correct a system inaccuracy on my part)
If you are concerned about the hydraulics and flight controls, the A380 flies fine with both hydraulic systems failed. Instead of a third hydraulic system for flight control redundancy, there are electrically powered actuators and electrical / hydraulic actuators to power the flight controls as well as standard actuators.
That is simplifying it, but there has been no sacrificing of redundancy.
N
(edited to correct a system inaccuracy on my part)
Last edited by noip; 19th Nov 2010 at 00:56.
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Barrymung,
If you'd bothered to read much of the thread you'd surely already be aware that no engine containment system can contain such a failure without making the aircraft unfeasibly heavy.
As an SLF who enjoys reading these fora I find it incredibly frustrating that people don't bother to read before posting. You professionals have my sympathy but please keep the fora open to SLF, we're not all lazy idiots like this fella.
If you'd bothered to read much of the thread you'd surely already be aware that no engine containment system can contain such a failure without making the aircraft unfeasibly heavy.
As an SLF who enjoys reading these fora I find it incredibly frustrating that people don't bother to read before posting. You professionals have my sympathy but please keep the fora open to SLF, we're not all lazy idiots like this fella.
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Barrymug
"Much has been said about the failure of the engine. However, not much has been said about the failure of the cowling itself.
I thought the cowling was supposed to prevent parts of the engine penetrating the wing in the event of catastrophic engine failure?
If the cowling had done it's job properly then the media would have dropped this story ages ago.."
Not so in Australia, Qantas bashing by the media is a National pastime and if it wasn't this incident, they would find another where they could then refer back to this one - as they are doing on a daily basis ATM.
"Much has been said about the failure of the engine. However, not much has been said about the failure of the cowling itself.
I thought the cowling was supposed to prevent parts of the engine penetrating the wing in the event of catastrophic engine failure?
If the cowling had done it's job properly then the media would have dropped this story ages ago.."
Not so in Australia, Qantas bashing by the media is a National pastime and if it wasn't this incident, they would find another where they could then refer back to this one - as they are doing on a daily basis ATM.
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Sounds like a description of the EHA / EBHAs on the A380, which provide the additioanl redundancy behind yellow/green hydraulic systems, and would appear to pre-date the 787...
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Sounds like a description of the EHA / EBHAs on the A380, which provide the additioanl redundancy behind yellow/green hydraulic systems, and would appear to pre-date the 787...
Mind you they don't provide any redundancy if the power to the EBHA's was cut by a disintergrating turbine disk
Noip
If what you state is true then why the degradation of spoilers. From looking at the design it looked to me like the backup is only to support the remaining hydraulic system to provide enough force to get home.
Were any flight demonstrations done with both primaries failed, or did they hide behind a SSA?
The Sultan
If what you state is true then why the degradation of spoilers. From looking at the design it looked to me like the backup is only to support the remaining hydraulic system to provide enough force to get home.
Were any flight demonstrations done with both primaries failed, or did they hide behind a SSA?
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Mind you they don't provide any redundancy if the power to the EBHA's was cut by a disintergrating turbine disk 
Funnily enough, the routing of said "power" is one of the biggest PIA's of the power route installation on an A380..............
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Sultan,
As was mentioned above, I was referring in particular to the EBHA but also the EHA actuators. They are not there to duplicate the entire Hydraulic system services but to power the flight controls and there are some EBHA dedicated to some spoilers. These actuators operate independently of the Hydraulic systems.
Degradation of Spoilers in this case is as you would expect in any aircraft losing a Hydraulic system.
There is a procedure to cover loss of fluid in both Hydraulic systems in the A380 - you get to fly in Alternate law and even have the use of the autopilot for the approach down to 500ft (because of the unusual configuration). And yes, you have antiskid braking, albeit with no autobrakes.
Flight demonstrations? I'm only a line pilot - wrong one to ask.
Helmut,
Only partially true. You would lose the power to the individual actuators, but you would be far better off than a conventional hydraulically powered machine. Depending on where the hydraulic fuses are in, say, a 747 you may lose all the hydraulics under such a circumstance and then you would be in deep trouble. Here, you would only lose some actuators and perhaps not the control surface, since there are two EHA for each aileron.
It doesn't matter which aircraft you fly, you can always pinpoint a weakness that will lead to a disastrous outcome, no matter how unlikely that may be. Just as you can point to the A380 and ask "How would it handle EMP?" you can think up an equally unlikely and silly thing to point at a 747 or whatever.
The 747 is an utterly magnificent design, however I've also found that it is obvious a lot of very clever people have put a lot of careful thought into the design of the A380.
N
As was mentioned above, I was referring in particular to the EBHA but also the EHA actuators. They are not there to duplicate the entire Hydraulic system services but to power the flight controls and there are some EBHA dedicated to some spoilers. These actuators operate independently of the Hydraulic systems.
Degradation of Spoilers in this case is as you would expect in any aircraft losing a Hydraulic system.
There is a procedure to cover loss of fluid in both Hydraulic systems in the A380 - you get to fly in Alternate law and even have the use of the autopilot for the approach down to 500ft (because of the unusual configuration). And yes, you have antiskid braking, albeit with no autobrakes.
Flight demonstrations? I'm only a line pilot - wrong one to ask.
Helmut,
Only partially true. You would lose the power to the individual actuators, but you would be far better off than a conventional hydraulically powered machine. Depending on where the hydraulic fuses are in, say, a 747 you may lose all the hydraulics under such a circumstance and then you would be in deep trouble. Here, you would only lose some actuators and perhaps not the control surface, since there are two EHA for each aileron.
It doesn't matter which aircraft you fly, you can always pinpoint a weakness that will lead to a disastrous outcome, no matter how unlikely that may be. Just as you can point to the A380 and ask "How would it handle EMP?" you can think up an equally unlikely and silly thing to point at a 747 or whatever.
The 747 is an utterly magnificent design, however I've also found that it is obvious a lot of very clever people have put a lot of careful thought into the design of the A380.
N
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A380 hydraulic systems redundancy
noip, Sultan & others,
Airbus claims to have performed an "all electric flight" during flight test (hydraulic systems depressurised).
Plus the EHA/EBHAs are not the systems of last resort. That task is given to the BPS/BCMs: Back-up power supply and Back-up control modules.
Airbus claims to have performed an "all electric flight" during flight test (hydraulic systems depressurised).
Plus the EHA/EBHAs are not the systems of last resort. That task is given to the BPS/BCMs: Back-up power supply and Back-up control modules.
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2 pieces of news out of Oz:
Alan Joyce says Rolls didn't tell Qantas they modified the engine design...
Airbus now wanting compensation from Rolls...
Both a bit of a blow for Rolls, I would think.
Alan Joyce says Rolls didn't tell Qantas they modified the engine design...
Airbus now wanting compensation from Rolls...
Both a bit of a blow for Rolls, I would think.
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Trent 972;
Which begs the question:-
Are each of these Hydraulic Systems designed for ultimate "self-protection" in event of a down-stream pressure loss?
Not much point powering the BPS if the above is not the case.
mm43
The BCM is powered by either of two Backup Power Supplies (BPS) which is an electrical generator each supplied by one of the Hydraulic Systems
Are each of these Hydraulic Systems designed for ultimate "self-protection" in event of a down-stream pressure loss?
Not much point powering the BPS if the above is not the case.
mm43
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Groaner said -
I am not sure where this comes from - this is what I found at
Rolls-Royce to replace 'up to 40' A380 engines: Qantas - Yahoo! News
It is not a very clear statement in my opinion. You certainly cannot conclude that RR were trying to hide anything.
Alan Joyce says Rolls didn't tell Qantas they modified the engine design...
Rolls-Royce to replace 'up to 40' A380 engines: Qantas - Yahoo! News
"It doesn't look like it is a significant modification, but it is a modification that has an impact on how the engines are performing," he said.
"If this was significant, and was known to be significant, we would have liked to have known about that," he added, noting that Rolls-Royce had begun modifying Trent 900 engines before this month's explosion.
"If this was significant, and was known to be significant, we would have liked to have known about that," he added, noting that Rolls-Royce had begun modifying Trent 900 engines before this month's explosion.
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A bit of a PR war going on. Qantas is exposing RR to improve its image and to make RR look bad (which they already do by engaging an "image management agency"). RR have totally misunderstood todays comms world as RR is not communicating about the issue at all.