Qantas A380 uncontained #2 engine failure
It asked the question why there were no British firms manufacturing computers
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Turbine D posted this link: High thrust Trent 900s limited to 75 flight cycles: Qantas
In the article Qantas states that
Now that bit might be true, but Qantas then go on to claim
It is this bit that I don't quite understand. Is he meaning to say that to get the fully loaded A380 off the ground LAX to SYD full 100% is needed from all four engines? No room to derate? If he does mean that, then how would he handle loss of an engine just after V1?
Sorry if it's a stupid question, i just don't understand the RR quotes.
In the article Qantas states that
Qantas Airways says the latest high thrust variants of the Rolls-Royce Trent 900 engines powering its Airbus A380 aircraft can be used for only 75 flights before needing replacement.
The disclosure was made in Qantas' affidavit against Rolls-Royce, which it alleges may have been "misleading or deceptive" when it proposed its Trent 900 engines to the carrier.
Qantas' statement of claim says engines with a "B mod" or "C mod" high pressure (HP)/intermediate pressure (IP) support structure need replacement after operating 75 take-offs at the 72,000lb maximum thrust level Rolls-Royce sold to Qantas.
The disclosure was made in Qantas' affidavit against Rolls-Royce, which it alleges may have been "misleading or deceptive" when it proposed its Trent 900 engines to the carrier.
Qantas' statement of claim says engines with a "B mod" or "C mod" high pressure (HP)/intermediate pressure (IP) support structure need replacement after operating 75 take-offs at the 72,000lb maximum thrust level Rolls-Royce sold to Qantas.
"Were the aircraft to be used with a full or commercially viable payload at the required thrust for take-off from [Los Angeles International Airport] LAX, the engines would need to be replaced after 75 such take-offs," Qantas General Manager Engineering and Maintenance Adrian Verkerk tells Qantas' lawyers in the affidavit.
Sorry if it's a stupid question, i just don't understand the RR quotes.
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Which "RR Quotes" would those be?? I'd like to see some RR quotes, got some?
I think "Derate" is NOT mandatory. If indicated for the mission, max thrust is selected if needed. Maybe I misunderstand the question.
"Replaced" after 75 MT T/O's?? Or reworked?? This has everything to do with the Splines AD's, since there is no "OIL STUB" mitigation in the AD's???? Have RR attempted to lay off the entire problem on a Stub Pipe (One Only) discovered on ONE, UNINSTALLED Powerplant??? Big Balls.......
bear
I think "Derate" is NOT mandatory. If indicated for the mission, max thrust is selected if needed. Maybe I misunderstand the question.
"Replaced" after 75 MT T/O's?? Or reworked?? This has everything to do with the Splines AD's, since there is no "OIL STUB" mitigation in the AD's???? Have RR attempted to lay off the entire problem on a Stub Pipe (One Only) discovered on ONE, UNINSTALLED Powerplant??? Big Balls.......
bear
Last edited by bearfoil; 14th Dec 2010 at 18:08.
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StickyB,
As you apparently don't have an even basic understanding of take off performance -and as there is enough talk about nothing here already- perhaps you should take your questions to a more appropriate forum.
As you apparently don't have an even basic understanding of take off performance -and as there is enough talk about nothing here already- perhaps you should take your questions to a more appropriate forum.
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stickyb
"No room to derate? If he does mean that, then how would he handle loss of an engine just after V1?"
If you're really a pilot, lucky my wife and kids are not on board.
If you're really a pilot, lucky my wife and kids are not on board.
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Bearfoil
To answer your question about EGT sensor location:
It is a matter of what location is available in a LPT module. The Stage 1 LPT nozzle has hollow airfoils, primarily for weight reduction purposes and not for air-cooling in most instances. As you move rearward in the module, the airfoils all become solid, and there is little space as the vanes are attached to the outer case, and the spaces in between the vanes at the outer case is reserved for blade tip sealing (honeycomb seals). The exterior of the LPT case is cluttered with case cooling tubing that is activated to maintain good sealing parameters at cruise (performance & efficiency). At the extreme aft end, the turbine rear frame serves as the support structure for the #8 bearing and contains the rear engine mounts. Although it may have hollow struts, these may be used for different purposes and would not be conducive for EGT sensors.
So, the Stage 1 LPT nozzle is chosen as the sensor location as the sensors are probably inside the hollow airfoils, not directly protruding into the gas stream.
Hope this answers your question.
Turbine D
To answer your question about EGT sensor location:
It is a matter of what location is available in a LPT module. The Stage 1 LPT nozzle has hollow airfoils, primarily for weight reduction purposes and not for air-cooling in most instances. As you move rearward in the module, the airfoils all become solid, and there is little space as the vanes are attached to the outer case, and the spaces in between the vanes at the outer case is reserved for blade tip sealing (honeycomb seals). The exterior of the LPT case is cluttered with case cooling tubing that is activated to maintain good sealing parameters at cruise (performance & efficiency). At the extreme aft end, the turbine rear frame serves as the support structure for the #8 bearing and contains the rear engine mounts. Although it may have hollow struts, these may be used for different purposes and would not be conducive for EGT sensors.
So, the Stage 1 LPT nozzle is chosen as the sensor location as the sensors are probably inside the hollow airfoils, not directly protruding into the gas stream.
Hope this answers your question.
Turbine D
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Turbine D:
It's quite possible - I might say likely - that one of the departing disk segments severed the EGT lead, either undercowl or in the wing LE.
The EGT temperature is sensed by a series of thermocouples in the Stage 1 LPT nozzle ring gas path. This comes from the Engine Type Certification Notice. Readings from these thermocouples went straight down at the disc burst point.
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The best answer for Qantas might be a variant of the A380 tailored to their needs and using the regular engines. Perhaps a shortened version with less weight to lift off the ground and flying a bit faster? It could be called the A380 Special Performance or A380SP for short. I wonder why nobody ever thought of this? 
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Perhaps a shortened version with less weight to lift off the ground and flying a bit faster?
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Qantas' statement of claim says engines with a "B mod" or "C mod" high pressure (HP)/intermediate pressure (IP) support structure need replacement after operating 75 take-offs at the 72,000lb maximum thrust level Rolls-Royce sold to Qantas.
Qantas pays for power by the hour, as far as cycles are concerned then the loss of revenue would be for the time for a 4 engine change, the turbine cost would have been on RR.
75 cycles, that is looking at turning the clock back to recip reliabilaty days, I find it hard to believe that Qantas or anyone else would have bought into that.
VFD
Trying to get a grip on this statement.
Qantas pays for power by the hour, as far as cycles are concerned then the loss of revenue would be for the time for a 4 engine change, the turbine cost would have been on RR.
75 cycles, that is looking at turning the clock back to recip reliabilaty days, I find it hard to believe that Qantas or anyone else would have bought into that.
VFD
Qantas pays for power by the hour, as far as cycles are concerned then the loss of revenue would be for the time for a 4 engine change, the turbine cost would have been on RR.
75 cycles, that is looking at turning the clock back to recip reliabilaty days, I find it hard to believe that Qantas or anyone else would have bought into that.
VFD
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You sir have made an inappropriate slur against some great engines
Just pointing out that turbines these days should be rated in 10's of thousands of cycles not 75.
VFD
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Willoz269:
Possibly because you posted a link to statements by the Professional Pilots actually involved in flying the beast, and the interview didn't involve rumours or hypothetical engineering discussions; thus offering the reader nothing to learn.
Why was my post with the interview of the Senior Captain on board QF32 removed?
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Maybe because it was already posted at #1735 on this thread?