Qantas A380 uncontained #2 engine failure
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Originally Posted by Peterd28
More Scuttlebutt from the Antipodes ( unverifiable source)
1. Bus #2 is supposedly automatically powered by Bus #1 in the event of Engine #2 failure - didn't happen.
2. Buses #3 & #4 will supposedly power Bus #2 in the even that the auto transfer from Bus #1 fails - didn't happen.
3. After some time the RAT deployed for no apparent reason, locking out (as a load-shedding function) some still functioning services.
4. One of the frequently recurring messages warned of the aircraft approaching the aft C of G limit (the procedure calls for transferring fuel forward), the next message advised of fwd transfer pumps being u/s. This sequence occurred repeatedly.
5. Apparently landing/approach speeds are obtained from the FMS, but there weren't anywhere near sufficient fields to load all the defects for speed corrections - the crew loaded what they thought were the most critical ones.
6. The crew commenced an approach NOT because they'd sorted out all the problems but because they were very worried about the way-out-of-tolerance and steadily worsening lateral imbalance.
7. The aircraft stopped with just over 100 metres or runway left, brakes temps climbed to 900C and fuel pouring out of the ruptured tank. Unable to shutdown #1 engine (as previously mentioned) but elected not to evacuate as the fire services were attending in great numbers.
8. The other comment from the source of the above (who was on the flight deck) was that the aeroplane did many things they simply didn't understand and/or failed to operate as expected
1. Bus #2 is supposedly automatically powered by Bus #1 in the event of Engine #2 failure - didn't happen.
2. Buses #3 & #4 will supposedly power Bus #2 in the even that the auto transfer from Bus #1 fails - didn't happen.
3. After some time the RAT deployed for no apparent reason, locking out (as a load-shedding function) some still functioning services.
4. One of the frequently recurring messages warned of the aircraft approaching the aft C of G limit (the procedure calls for transferring fuel forward), the next message advised of fwd transfer pumps being u/s. This sequence occurred repeatedly.
5. Apparently landing/approach speeds are obtained from the FMS, but there weren't anywhere near sufficient fields to load all the defects for speed corrections - the crew loaded what they thought were the most critical ones.
6. The crew commenced an approach NOT because they'd sorted out all the problems but because they were very worried about the way-out-of-tolerance and steadily worsening lateral imbalance.
7. The aircraft stopped with just over 100 metres or runway left, brakes temps climbed to 900C and fuel pouring out of the ruptured tank. Unable to shutdown #1 engine (as previously mentioned) but elected not to evacuate as the fire services were attending in great numbers.
8. The other comment from the source of the above (who was on the flight deck) was that the aeroplane did many things they simply didn't understand and/or failed to operate as expected
i think your post will appear in the media before the day is out as ` an unamed source close to the incident`
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I think the torque depends on Mass, so the Big Fan would be the logical Contra candidate. But with OEI, the benefit would be a crapshoot.
Like the flying wing, Contra-Rotation of rotating mass(es) has been an obsession with engineers, and repeatedly fails to impress. It very nearly killed Howard Hughes, (Pratt), Steve Hinton (Rolls Royce), and with the wing, did kill Glenn Edwards.
Somewhere in a torque compensating system with contra rotation, relative velocities of rotating mass double. Heat, wear, inspection, complexity, etc. Worth it?
bear
Like the flying wing, Contra-Rotation of rotating mass(es) has been an obsession with engineers, and repeatedly fails to impress. It very nearly killed Howard Hughes, (Pratt), Steve Hinton (Rolls Royce), and with the wing, did kill Glenn Edwards.
Somewhere in a torque compensating system with contra rotation, relative velocities of rotating mass double. Heat, wear, inspection, complexity, etc. Worth it?
bear
Second Law
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Bear,
You are, as ever, spot on sir
I was taught that torque was rate of change of angular momentum, and that momentum is mass x velocity.
Yes I know, the mathematics here can be bracing.
In short, torque is directly proportionate to mass.
CW
You are, as ever, spot on sir
I was taught that torque was rate of change of angular momentum, and that momentum is mass x velocity.
Yes I know, the mathematics here can be bracing.
In short, torque is directly proportionate to mass.
CW
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Why are we suddenly talking about torque, when a minute ago it was gyrational precession forces?
Contra-rotating props have been very succesful in many aircraft - ask a Seafire pilot to compare his go-around experiences with a Sea Fury pilot for instance.
Like the flying wing, Contra-Rotation of rotating mass(es) has been an obsession with engineers, and repeatedly fails to impress.
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seafire / fury
to the best of my knowledge, apart from proof of concept very late marks, neither was operational sporting contra rotating props ... of course I stand to be corrected.
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RR Griffon CR Seafires were at sea in service... I am pretty sure
Griffon Shackletons
The big long range Russian Bears
RR Griffon Martin Baker MB-5 (ease and safety of take-offs complimented for a 460mph fighter)
All Mk 47s were contra-rotating and some of the 20 Mk 46s
Griffon Shackletons
The big long range Russian Bears
RR Griffon Martin Baker MB-5 (ease and safety of take-offs complimented for a 460mph fighter)
The Seafire 47 saw action with 800 Squadron on board HMS Triumph during the Malayan Emergency of 1949 and during the Korean War in 1950. However, in 1951 all Seafires were withdrawn from front-line service.[17] In all 90 F. and F.R Mk 47s were built, all by Supermarine..
Last edited by HarryMann; 14th Nov 2010 at 22:41.
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Another 7 Qantas engines to be replaced
from the Brisbane Times
THE British jet-engine maker Rolls-Royce has told Qantas that it is likely to have to replace another seven engines on its A380 superjumbo fleet after inspections found the potential for oil leaks.
Singapore Airlines is also believed to have been informed that it will have to change up to 20 of the Trent 900 engines used on its fleet of 11 A380s, while the German airline Lufthansa faces two replacements.
The latest advice from Rolls-Royce means up to 29 replacement engines will have to be found. It confirmed on Friday that the failure of a ''specific component in the turbine area of the engine'' on a Qantas A380 on November 4 shortly after take-off from Singapore caused an oil fire that led to a turbine disc exploding.
The need for replacement engines creates headaches for the three airlines whose A380s are powered by the Rolls-Royce Trent 900s due to a lack of spares. Because the A380 superjumbos are such new aircraft, Rolls-Royce and the aircraft manufacturer Airbus do not have a ready supply of engines.
Qantas has already had discussions with Airbus and Rolls-Royce about obtaining replacement engines should they be required, placing it ahead of Singapore Airlines and Lufthansa. However, the likelihood of further engine changes means it could take longer for Qantas to return its A380s to service and cost it more in lost revenue.
''The longer it goes on the worse it gets for them - they don't want those planes out of service for too long,'' an analyst said. Qantas has so far replaced three engines on three separate aircraft since it grounded its A380 fleet on November 4 but has been told by Rolls-Royce that it could have to replace as many as seven more. Even if some do not have to be changed, engineers are likely to have to make modifications to the engines.
Singapore Airlines grounded three A380s last week to allow for three engines to be replaced. Two of the aircraft have since returned to service while the engine change to the other A380 is almost complete. It takes up to 36 hours to replace an engine.
A spokesman for Singapore Airlines, Nicholas Ionides, said last night that he could not ''speak definitely'' about the number of engines that might have to be changed because investigations had not been completed.
Qantas said it was continuing to inspect engines on its A380s to meet the requirements under the airworthiness directive issued last week by the European Aviation Safety Agency.
Meanwhile, air-safety investigators have discovered that the audio from QF32's cockpit voice recorder at the time of the engine failure has been lost. The safety bureau said the audio was overwritten because the recorder, which is on a continuous loop, taped the pilots for more than two hours after the engine blew.
A bureau spokesman, Richard Batt, said the loss of the audio was not a significant issue.
THE British jet-engine maker Rolls-Royce has told Qantas that it is likely to have to replace another seven engines on its A380 superjumbo fleet after inspections found the potential for oil leaks.
Singapore Airlines is also believed to have been informed that it will have to change up to 20 of the Trent 900 engines used on its fleet of 11 A380s, while the German airline Lufthansa faces two replacements.
The latest advice from Rolls-Royce means up to 29 replacement engines will have to be found. It confirmed on Friday that the failure of a ''specific component in the turbine area of the engine'' on a Qantas A380 on November 4 shortly after take-off from Singapore caused an oil fire that led to a turbine disc exploding.
The need for replacement engines creates headaches for the three airlines whose A380s are powered by the Rolls-Royce Trent 900s due to a lack of spares. Because the A380 superjumbos are such new aircraft, Rolls-Royce and the aircraft manufacturer Airbus do not have a ready supply of engines.
Qantas has already had discussions with Airbus and Rolls-Royce about obtaining replacement engines should they be required, placing it ahead of Singapore Airlines and Lufthansa. However, the likelihood of further engine changes means it could take longer for Qantas to return its A380s to service and cost it more in lost revenue.
''The longer it goes on the worse it gets for them - they don't want those planes out of service for too long,'' an analyst said. Qantas has so far replaced three engines on three separate aircraft since it grounded its A380 fleet on November 4 but has been told by Rolls-Royce that it could have to replace as many as seven more. Even if some do not have to be changed, engineers are likely to have to make modifications to the engines.
Singapore Airlines grounded three A380s last week to allow for three engines to be replaced. Two of the aircraft have since returned to service while the engine change to the other A380 is almost complete. It takes up to 36 hours to replace an engine.
A spokesman for Singapore Airlines, Nicholas Ionides, said last night that he could not ''speak definitely'' about the number of engines that might have to be changed because investigations had not been completed.
Qantas said it was continuing to inspect engines on its A380s to meet the requirements under the airworthiness directive issued last week by the European Aviation Safety Agency.
Meanwhile, air-safety investigators have discovered that the audio from QF32's cockpit voice recorder at the time of the engine failure has been lost. The safety bureau said the audio was overwritten because the recorder, which is on a continuous loop, taped the pilots for more than two hours after the engine blew.
A bureau spokesman, Richard Batt, said the loss of the audio was not a significant issue.
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Rolls-Royce's A380 engines to be removed for oil fix
ABOUT half the Rolls-Royce Trent 900 engines powering Airbus A380s, including 14 Qantas engines, will need to be taken off and dismantled.
The process would fix components involved in a potentially dangerous oil leak.
The Australian has been told about 40 engines on the 20 A380s operated by Qantas, Singapore Airlines and Lufthansa need to be modified to fix the leaks. This includes 24 at Singapore Airlines and two at Lufthansa.
The modification, described by Rolls-Royce as the replacement of a module and understood to involve a bearing box, requires the engines to be taken off the wing and stripped down so engineers can access the affected area.
Industry players expect the work to strain both resources and parts availability and say the British manufacturer is looking at establishing stations around the world to do the work.
The modifications aim to prevent a repeat of an oil fire blamed for the disintegration of a turbine disc that saw a Qantas Trent 900 rip itself apart, peppering the wing of an A380 with shrapnel and causing substantial damage.
Rolls also plans to introduce a software fix that will shut down the engine before it reaches a point where the turbine disc is in danger of disintegrating.
The incident prompted Qantas to ground its A380 fleet and the airline was still unsure yesterday about when the superjumbos would resume flying.
It expects the A380s to be returned to service on a plane-by-plane basis and Airbus has offered to help by taking already modified engines from its production line and shipping them to Qantas.
A spokesman said Qantas would work with both Airbus and Rolls-Royce to work out "the fastest and most effective way of ensuring its engines were up to the latest variation".
Singapore, which has grounded three planes and has the oldest A380s as well as the biggest fleet of 11 aircraft, would not confirm the number of engines requiring modifications.
A Singapore spokesman said the airline was continuing to inspect the engines in accordance with a European airworthiness directive that allowed operations to continue safely.
The process would fix components involved in a potentially dangerous oil leak.
The Australian has been told about 40 engines on the 20 A380s operated by Qantas, Singapore Airlines and Lufthansa need to be modified to fix the leaks. This includes 24 at Singapore Airlines and two at Lufthansa.
The modification, described by Rolls-Royce as the replacement of a module and understood to involve a bearing box, requires the engines to be taken off the wing and stripped down so engineers can access the affected area.
Industry players expect the work to strain both resources and parts availability and say the British manufacturer is looking at establishing stations around the world to do the work.
The modifications aim to prevent a repeat of an oil fire blamed for the disintegration of a turbine disc that saw a Qantas Trent 900 rip itself apart, peppering the wing of an A380 with shrapnel and causing substantial damage.
Rolls also plans to introduce a software fix that will shut down the engine before it reaches a point where the turbine disc is in danger of disintegrating.
The incident prompted Qantas to ground its A380 fleet and the airline was still unsure yesterday about when the superjumbos would resume flying.
It expects the A380s to be returned to service on a plane-by-plane basis and Airbus has offered to help by taking already modified engines from its production line and shipping them to Qantas.
A spokesman said Qantas would work with both Airbus and Rolls-Royce to work out "the fastest and most effective way of ensuring its engines were up to the latest variation".
Singapore, which has grounded three planes and has the oldest A380s as well as the biggest fleet of 11 aircraft, would not confirm the number of engines requiring modifications.
A Singapore spokesman said the airline was continuing to inspect the engines in accordance with a European airworthiness directive that allowed operations to continue safely.
Are stators dispensed with?
There has been talk that contra-rotation between the HP and IP spools could remove the need for one or even two stator stages.
But that also happens to be where at least the HP bearings have to be rigidly supported. Surrounding a bearing support with stators allows for plenty of structure to keep it properly anchored. When you don't have stators, what's going to do the job? Remember that efficiency requires small clearances between the stages.
But that also happens to be where at least the HP bearings have to be rigidly supported. Surrounding a bearing support with stators allows for plenty of structure to keep it properly anchored. When you don't have stators, what's going to do the job? Remember that efficiency requires small clearances between the stages.
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Hi,
Seem's to me they replace engines with problems by new not modified .. so the problem stay the same .. or .... all those new engines are already corrected (RR know exactly what is the problem ?) and if so I must tell kudos to RR engineers .. they are "magics" to correct soooo much engines is soooo short time
Plaster on a wooden leg
Seem's to me they replace engines with problems by new not modified .. so the problem stay the same .. or .... all those new engines are already corrected (RR know exactly what is the problem ?) and if so I must tell kudos to RR engineers .. they are "magics" to correct soooo much engines is soooo short time
Plaster on a wooden leg
But that also happens to be where at least the HP bearings have to be rigidly supported. Surrounding a bearing support with stators allows for plenty of structure to keep it properly anchored. When you don't have stators, what's going to do the job? Remember that efficiency requires small clearances between the stages.
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Commercial decisions? Safety related decisions? Media correct decisions?
SQ opted to fly those planes found to have oil leak stains back to SIN for engine change.
QF left 2 sitting idle in LAX.
SQ clearly made a commercially driven decision backed up with technical spin as to the safe worthiness of flying the A380s home.
QF obviously overreacted to satisfy the media hungry.
QF left 2 sitting idle in LAX.
SQ clearly made a commercially driven decision backed up with technical spin as to the safe worthiness of flying the A380s home.
QF obviously overreacted to satisfy the media hungry.
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List First...
Gob writes:
No professional journalist would copy information from PPRuNe ... to do your job as a journalist and check the information is reliable, then you can count me out as a reader.
No professional journalist would copy information from PPRuNe ... to do your job as a journalist and check the information is reliable, then you can count me out as a reader.
But it *has* been repeated in the relevant thread there at least 3 times I am aware of.
RE: "With respect, Ancient Geek, I said 'professional' journalist."
And so it goes...
JFZ90 writes:
Given the way the info is now being used to sensationalise and may in the worst case affect (unfairly) public perception of A380- you should be careful. Unlike many on here who just want to understand what went wrong, journos have a different agenda and can't generally be trusted!
Given the way the info is now being used to sensationalise and may in the worst case affect (unfairly) public perception of A380- you should be careful. Unlike many on here who just want to understand what went wrong, journos have a different agenda and can't generally be trusted!
I really hope you don't think Para's posting of an existing AD will unfairly affect public perception of the A380.
Also, I haven't seen much sensastionization, save for what has been appearing in Aussie rags - which has mostly been cheap papers taking shots at Qantas, not the A380.
Algy writes:
Slightly surprised to see the FAA issuing an AD on an aircraft which, as they point out, is not in service with any US operator. I didn't realise they ever did that.
Slightly surprised to see the FAA issuing an AD on an aircraft which, as they point out, is not in service with any US operator. I didn't realise they ever did that.
I'm in favor of this approach, not because I'm pro-Boeing but because it promotes safety "here" and there. Eventually the A380 will be picked up by US operators, and this is just one more way of making them as safe as possible.
I'm not an Airbus fan, but I must admit this frame sustained a good bit of damage and managed to deliver all on board safely back to earth. Hopefully it can be repaired back to spec and continue a long career.
Bearfoil writes:
This engine is built like a battleship; stresses within can be understood mathematically, but seldom viscerally
This engine is built like a battleship; stresses within can be understood mathematically, but seldom viscerally
Even RR themselves have promoted the Trent 900 as being extremely efficient, as light as possible, with the best economy.
Speaking to recent events, apparently not all stresses within were understood.
Peter writes:
7. The aircraft stopped with just over 100 metres or runway left,
7. The aircraft stopped with just over 100 metres or runway left,
Nice that it DID stop there.
I'm really hoping this turns out to be less worse than it seems at the moment, and that the widely-published "20 to 40 engines" which could possibly need replacement is hype and exaggeration. It would truly be a shame for RR to have stepped in this much dung.
Cheers!
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Originally Posted by chris weston
Bear,
You are, as ever, spot on sir
I was taught that torque was rate of change of angular momentum, and that momentum is mass x velocity.
Yes I know, the mathematics here can be bracing.
In short, torque is directly proportionate to mass.
CW
You are, as ever, spot on sir
I was taught that torque was rate of change of angular momentum, and that momentum is mass x velocity.
Yes I know, the mathematics here can be bracing.
In short, torque is directly proportionate to mass.
CW
For fun, I want to compute the energy of an IP disc at full throttle... something like 8,000 RPM at max rotor speeds. But, I have not been able to find any information as to the approximate diameter and mass of an IP disc for this engine, making the exercise somewhat difficult.
Does anyone have approximate values for these parameters?
TIA
PS: A couple of interesting reference documents.
http://www.rolls-royce.com/Images/ga...tcm92-4977.pdf
http://www.easa.europa.eu/certificat...4-24052007.pdf
http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgMakeModel.nsf/0/09b47c27a9cfb982862573080054f9ea/$FILE/E00075EN.pdf
Last edited by StrongEagle; 15th Nov 2010 at 11:26.
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Capt Groper
My understanding of the EBHA function is the same as yours, but I'm not a specialist either.
It seems the EBHA is supposed to shift from main hydraulics to local hydraulics under electric power in the case of main hyd system failure.
In short, spoiler #6 should have deployed if it had electrics.
It seems the EBHA is supposed to shift from main hydraulics to local hydraulics under electric power in the case of main hyd system failure.
In short, spoiler #6 should have deployed if it had electrics.