Qantas A380 uncontained #2 engine failure
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Posted by Grumpi
I believe this this is the most plausible explanation for the image I posted ..
"@ Thrusty, Feathers, and others who are discussing the pic of the recovered disk in post #682:
You are aware that the poster has INVERTED the colors of that image as described, and as per instructions of post #629, and that the dark marks are thus actually bright marks in reality?
The round star shaped thing anyways is with 99% certainty the boundary of a reflection of a bright window to the right of the image. You can even see the outline from a part of the cart handle..."
TR
"@ Thrusty, Feathers, and others who are discussing the pic of the recovered disk in post #682:
You are aware that the poster has INVERTED the colors of that image as described, and as per instructions of post #629, and that the dark marks are thus actually bright marks in reality?
The round star shaped thing anyways is with 99% certainty the boundary of a reflection of a bright window to the right of the image. You can even see the outline from a part of the cart handle..."
TR
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"* massive fuel leak in the left mid fuel tank (the beast has 11 tanks, including in the horizontal stabiliser on the tail)"any picture to proof this ?
"* massive fuel leak in the left inner fuel tank" think yes,but could be Feeder 2 instead.
"* a hole on the flap canoe/fairing that you could fit your upper body through" any picture ?
"* the aft gallery in the fuel system failed, preventing many fuel transfer
functions" there is a second gallery and lot of manual pump/valve switching available.
"* fuel jettison had problems due to the previous problem above" Heard they were dumping fuel for 90 min.
"* bloody great hole in the upper wing surface" Yes,indeed.
"* partial failure of leading edge slats" No,they are all driven by the same device and cannot fail partial.
"* partial failure of speed brakes/ground spoilers" Yes due to missing hydraulic.Another issue seems the function of Spoiler 5 and 6 -they are driven by EBHAs and should have worked both.
"* shrapnel damage to the flaps" Picture available ?
"* TOTAL loss of all hydraulic fluid in the Green System (beast has 2 x
5,000 PSI systems, Green and Yellow) "Correct .
"* manual extension of landing gear" Correct.
"* loss of 1 generator and associated systems" Associated systems are
supplied by 3 remaining gennys and below FL250 you can start the APU.
"* loss of brake anti-skid system" Why ?
"* unable to shutdown adjacent #1 engine using normal method after landing
due to major damage to systems
* unable to shutdown adjacent #1 engine using using the fire switch!!!!!!!!
Therefore, no fire protection was available for that engine after the
explosion in #2" This is a strange one,no doubt !
"* ECAM warnings about major fuel imbalance because of fuel leaks on left side, that were UNABLE to be fixed with cross-feeding" New to me...
"* fuel trapped in Trim Tank (in the tail). Therefore, possible major CofG
out-of-balance condition for landing" The fuel from the Trim Tank is normaly used after 12h of Flighttime.
To complete the list:-possible highspeed and/overweight landing-
3 burst tyres as a result.
-No reverser on No2 therefor still power (think much more than Idle)
from No1.
The crew did a perfect job,the aircraft design kept everybody alive-
but may be the A380 used all it`s luck for the next years.
"* massive fuel leak in the left inner fuel tank" think yes,but could be Feeder 2 instead.
"* a hole on the flap canoe/fairing that you could fit your upper body through" any picture ?
"* the aft gallery in the fuel system failed, preventing many fuel transfer
functions" there is a second gallery and lot of manual pump/valve switching available.
"* fuel jettison had problems due to the previous problem above" Heard they were dumping fuel for 90 min.
"* bloody great hole in the upper wing surface" Yes,indeed.
"* partial failure of leading edge slats" No,they are all driven by the same device and cannot fail partial.
"* partial failure of speed brakes/ground spoilers" Yes due to missing hydraulic.Another issue seems the function of Spoiler 5 and 6 -they are driven by EBHAs and should have worked both.
"* shrapnel damage to the flaps" Picture available ?
"* TOTAL loss of all hydraulic fluid in the Green System (beast has 2 x
5,000 PSI systems, Green and Yellow) "Correct .
"* manual extension of landing gear" Correct.
"* loss of 1 generator and associated systems" Associated systems are
supplied by 3 remaining gennys and below FL250 you can start the APU.
"* loss of brake anti-skid system" Why ?
"* unable to shutdown adjacent #1 engine using normal method after landing
due to major damage to systems
* unable to shutdown adjacent #1 engine using using the fire switch!!!!!!!!
Therefore, no fire protection was available for that engine after the
explosion in #2" This is a strange one,no doubt !
"* ECAM warnings about major fuel imbalance because of fuel leaks on left side, that were UNABLE to be fixed with cross-feeding" New to me...
"* fuel trapped in Trim Tank (in the tail). Therefore, possible major CofG
out-of-balance condition for landing" The fuel from the Trim Tank is normaly used after 12h of Flighttime.
To complete the list:-possible highspeed and/overweight landing-
3 burst tyres as a result.
-No reverser on No2 therefor still power (think much more than Idle)
from No1.
The crew did a perfect job,the aircraft design kept everybody alive-
but may be the A380 used all it`s luck for the next years.
Cunning Artificer
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@no hoper
OK, post#300 on this thread would appear to be the source.
Furthermore, if you look down to posts #310 and 311, there is some speculation as to severe spar damage.
No hoper, you ask is I have photo evidence, a very easy question to ask.
No I don't, but to reverse the question back to you, do you have photos to disprove the suggestions?
OK, post#300 on this thread would appear to be the source.
Furthermore, if you look down to posts #310 and 311, there is some speculation as to severe spar damage.
No hoper, you ask is I have photo evidence, a very easy question to ask.
No I don't, but to reverse the question back to you, do you have photos to disprove the suggestions?
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http://www.caa.co.uk/application.asp...detail&id=4318
EASA EAD 2010-0236-E: RB211 Trent 900 series engines: Engine - High Pressure / Intermediate Pressure (HP/IP) Structure - Inspections Analysis of the preliminary elements from the incident investigation shows that an oil fire in the HP/IP structure cavity may have caused the failure of the Intermediate Pressure Turbine (IPT) Disc.
This condition, if not detected, could ultimately result in uncontained engine failure potentially leading to damage to the aeroplane and hazards to persons or property on the ground.
For the reasons described above and pending conclusion of the incident investigation, this AD requires repetitive inspections of the Low Pressure Turbine (LPT) stage 1 blades and case drain, HP/IP structure air buffer cavity and oil service tubes in order to detect any abnormal oil leakage, and if any discrepancy is found, to prohibit further engine operation.
EASA EAD 2010-0236-E: RB211 Trent 900 series engines: Engine - High Pressure / Intermediate Pressure (HP/IP) Structure - Inspections Analysis of the preliminary elements from the incident investigation shows that an oil fire in the HP/IP structure cavity may have caused the failure of the Intermediate Pressure Turbine (IPT) Disc.
This condition, if not detected, could ultimately result in uncontained engine failure potentially leading to damage to the aeroplane and hazards to persons or property on the ground.
For the reasons described above and pending conclusion of the incident investigation, this AD requires repetitive inspections of the Low Pressure Turbine (LPT) stage 1 blades and case drain, HP/IP structure air buffer cavity and oil service tubes in order to detect any abnormal oil leakage, and if any discrepancy is found, to prohibit further engine operation.
kwateow
Agreed. SQ seem to have 8 out of 11 aircraft still in service. The 3 "grounded aircraft" were not really grounded as they were flown (without pax) from LHR, SYD and MEL to SIN before the engines were planned to be removed.
Agreed. SQ seem to have 8 out of 11 aircraft still in service. The 3 "grounded aircraft" were not really grounded as they were flown (without pax) from LHR, SYD and MEL to SIN before the engines were planned to be removed.
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With respect to shinobi1, here is the correct link to the AD as published by the CAA.
The link should work from there, but here is the full URL;
http://www.caa.co.uk/application.aspx?catid=33&pagetype=65&appid=11&mode=detail&i d=4319
The link should work from there, but here is the full URL;
http://www.caa.co.uk/application.aspx?catid=33&pagetype=65&appid=11&mode=detail&i d=4319
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ATSB is THE source.
All of the last comments, while pointing to various (may I say, unreliable?) media sources, are ultimately inspired by the ATSB website. They have daily updates over the progress of this investigation. Though it doesn't put to rest any "rumours", at least, it directs these in a sounder direction.
I just wanted to commend how the Aussies do business here. Even though, like all other authorities in this matter, they warn we shouldn't draw any definitive conclusions over what they regularly report, I believe it informs better the flying public, so people can make for themselves an enlightened decision to fly or not on this (or any other) type. T's'way better than how our Canadian TSB, the NTSB, and the now "dubious in the face of their own public" French BEA let you hang to dry until the ICAO rules force them to come out with a report.
So, if you want to follow this investigation almost "live", loose the media sources and go where them medias take their own informations and consult it before they can twist it in sometimes wacky manners: the ATSB's website. These guys rule.
I just wanted to commend how the Aussies do business here. Even though, like all other authorities in this matter, they warn we shouldn't draw any definitive conclusions over what they regularly report, I believe it informs better the flying public, so people can make for themselves an enlightened decision to fly or not on this (or any other) type. T's'way better than how our Canadian TSB, the NTSB, and the now "dubious in the face of their own public" French BEA let you hang to dry until the ICAO rules force them to come out with a report.
So, if you want to follow this investigation almost "live", loose the media sources and go where them medias take their own informations and consult it before they can twist it in sometimes wacky manners: the ATSB's website. These guys rule.
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All these people foretelling gloom and doom for RR are obviously too young to remember the first B747's sitting on the ramp in Seattle with concrete blocks tied to the nacelles waiting for P&W to sort out the ovalating problem
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For the reasons described above and pending conclusion of the incident investigation, this AD requires repetitive inspections of the Low Pressure Turbine (LPT) stage 1 blades and case drain, HP/IP structure air buffer cavity and oil service tubes in order to detect any abnormal oil leakage, and if any discrepancy is found, to prohibit further engine operation.
We have a seal structure that for lack of a better term has a weepage and drain tubes to handle normal flow provided that there is a proper pressure supplied in the air buffer cavity.
So for lack of a better analogy then possibly there is some disturbance in the air buffer pressue cavity supply that can happen at higher thrust settings allowing the seal to become ineffective due to the higher gas velocities at or near the air supply point for the air buffer cavity.
Just a wild guess, if so could be an easy fix to the design.
VFD
rethink?
Is it simply the case that uncontained failures have not (yet) risen to the top of the risk matrix, rather than it is impossible to protect against them as some are saying?
By virtue of the high number of passengers (873) the plane can carry does the risk matrix for A380 engines need a rethink?
The "Value of statistical life" is the amount that the US government thinks we should pay to reduce the probability of some particular person’s death from 1.00 (that is, death with certainty) to 0 (perfect safety). In 2008 the figure was US$6.9m. This is the cost to society overall of a premature death by accident.
So a fully loaded airbus carries human cargo totaling $5.8 billion in "statistical value".
Chainsaw Chaps pants can jam a chain in an instant, kevlar can stop a bullet, lightweight ceramic plates absorb high velocity projectiles, F1 cars can contain a separated wheel, so adding a few inches to the diameter of the engine to install some kind of custom new and expensive material is feasible?
The question is, who would pay for the research?
Mickjoebill
By virtue of the high number of passengers (873) the plane can carry does the risk matrix for A380 engines need a rethink?
The "Value of statistical life" is the amount that the US government thinks we should pay to reduce the probability of some particular person’s death from 1.00 (that is, death with certainty) to 0 (perfect safety). In 2008 the figure was US$6.9m. This is the cost to society overall of a premature death by accident.
So a fully loaded airbus carries human cargo totaling $5.8 billion in "statistical value".
Chainsaw Chaps pants can jam a chain in an instant, kevlar can stop a bullet, lightweight ceramic plates absorb high velocity projectiles, F1 cars can contain a separated wheel, so adding a few inches to the diameter of the engine to install some kind of custom new and expensive material is feasible?
The question is, who would pay for the research?
Mickjoebill
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I take it your not an engineer then?
you need to consider the mass/velocity of the object in question here.
A chainsaw's chain/clutch/engine has very little mass, thus even at speed, there's very little inertia to deal with.
same for an F1 car, the whole car is only slightly over 400Kg's (without driver/fuel etc), so relatively speaking, even at 200Mph, it's still nothing like the same energy as the rotational parts of a jet engine.
realistically, you would need significant shielding to stop this kind of part breaking out, to the point you would be increasing the weight/size of the engine by 2-3 times with still no guarantee that this would stop *any* failure breaking out.
you need to consider the mass/velocity of the object in question here.
A chainsaw's chain/clutch/engine has very little mass, thus even at speed, there's very little inertia to deal with.
same for an F1 car, the whole car is only slightly over 400Kg's (without driver/fuel etc), so relatively speaking, even at 200Mph, it's still nothing like the same energy as the rotational parts of a jet engine.
realistically, you would need significant shielding to stop this kind of part breaking out, to the point you would be increasing the weight/size of the engine by 2-3 times with still no guarantee that this would stop *any* failure breaking out.
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And you know
All these people foretelling gloom and doom for RR are obviously too young to remember the first B747's sitting on the ramp in Seattle with concrete blocks tied to the nacelles waiting for P&W to sort out the ovalating problem
Time to buy some RR stock if you have some spare change. Them brokers have all sold theirs high at the beginning of this story, making by themselve this title plunge faster than a "Widow Maker", and are getting ready to buy it back low, just about now. That's how you take care of business on the stock market... inducing panic pays way better on the ground.
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VFD
Someone is going to have to help me out here.
We have a seal structure that for lack of a better term has a weepage and drain tubes to handle normal flow provided that there is a proper pressure supplied in the air buffer cavity.
So for lack of a better analogy then possibly there is some disturbance in the air buffer pressue cavity supply that can happen at higher thrust settings allowing the seal to become ineffective due to the higher gas velocities at or near the air supply point for the air buffer cavity.
Just a wild guess, if so could be an easy fix to the design.
We have a seal structure that for lack of a better term has a weepage and drain tubes to handle normal flow provided that there is a proper pressure supplied in the air buffer cavity.
So for lack of a better analogy then possibly there is some disturbance in the air buffer pressue cavity supply that can happen at higher thrust settings allowing the seal to become ineffective due to the higher gas velocities at or near the air supply point for the air buffer cavity.
Just a wild guess, if so could be an easy fix to the design.
Think of a turbine disk... there will be a pressure drop across the turbine disk as the hot gases flow through it. The overall pressure ratio of a Trent 970 is about 39:1, I believe, so (very simply), that's the pressure drop that is taking place across all the turbine stages. You can't 'seal' the gas passage, so the faces of the disk 'see' the pressure that is in the gas stream. Thus the pressure on the face of the disk will be higher on the upstream side compared to that on the downstream side.
Now think of a bearing chamber that is supporting the shaft that carries that disk. There will be a higher pressure on one side of the bearing chamber compared to the other.
Balancing up all those pressures, removing, or scavenging, the oil from the bearing chambers so that it serves its purpose of heat removal and lubrication, and at the same time ensuring that the pressure in the bearing chamber is (crudely), lower than the pressure outside the bearing chamber so that oil does not flow out past the seals, are all part of the air and oil system design of the engine. And it's an important phase of the development testing.
So, if something has happened to disturb that carefully balanced system, then possibly there is oil leaking where there should not be oil; which is what seems to be reported. That leakage can lead to a fire, and a softened disk, which then maybe lets its blades go, and departs from the engine.
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Thanks Gem
Since we are speculating then posibly the why we are seeing the issue with the 972 and not the 970 is due to additional pressures or gas velocity due to the higher rated models effecting the balance.
Could be something that did not transfer over to the production turbine vs the prototype/test unit. There have been several mentions of the drain tubes plugging/coking over time which might decrease the ability to drain the oil away instead of being fuel to melt the disk when there is an improper balance.
Thanks again Gem
VFD
So, if something has happened to disturb that carefully balanced system, then possibly there is oil leaking where there should not be oil; which is what seems to be reported. That leakage can lead to a fire, and a softened disk, which then maybe lets its blades go, and departs from the engine
Could be something that did not transfer over to the production turbine vs the prototype/test unit. There have been several mentions of the drain tubes plugging/coking over time which might decrease the ability to drain the oil away instead of being fuel to melt the disk when there is an improper balance.
Thanks again Gem
VFD