QANTAS A380 Uncontained failure.
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Yes, just those. Keep in mind, the QF32 #2 IPT failed at a Thrust value of 72,000 POT. This power is commanded by the added Data Entry Plug, (DEP). The Max RPMS are limits that pertain to the base engine; by claim, the 900 can produce 80,000 POT. Where is the extra Power derived? The failure of the EEC to control the first bump of Added Thrust either in not sampling the "Oil Fire's" production of wavering power, high temps and Oil Pressure anomalies, or over "limit" RPM shows us that the engine is not dependable at this very first Power increase (72). This engine is a different "TRENT". The discrepant RPM limits are evidence of this.
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lomapaeso
To add to your explanation to radken: Assuming the disc began to stretch, because of overspeed and presence of higher than designed for temperatures in the bore area, the turbine blades could have started to unlatch at the tip shrouds. Since the tip shrouds provide blade dampening, it would have been the beginning of the end for the turbine blades very quickly, even without any contact with other adjacent components. The extreme unbalance created would be catastrophic to the disc already operating beyond its design capability.
To add to your explanation to radken: Assuming the disc began to stretch, because of overspeed and presence of higher than designed for temperatures in the bore area, the turbine blades could have started to unlatch at the tip shrouds. Since the tip shrouds provide blade dampening, it would have been the beginning of the end for the turbine blades very quickly, even without any contact with other adjacent components. The extreme unbalance created would be catastrophic to the disc already operating beyond its design capability.
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Turbine D
It is an assumption that there was Stretch due excess Heat. Would not the Disc fail instantly even at in limit RPM once the Drive Arm fractured? Also, Contact of any description IPT/NGV Platform would be exactly simultaneous with aft movement of Shaft??
Given the AD's, and their warning of Metal/Metal with aftward drift, isn't the better assumption that the Disc Fractured after contact with Stationery Parts, melted, Disintegrated, and caused burst?? I see no need to entertain Fire, or Blade shear to explain this Engine Explosion. The simpler explanation is generally assumed to be the more likely cause, No?
Applying Occam, then, we can simplify the assumed failure to include no fire, no overspeed (save after fracture), and no need to index the Failure with cockpit data (displayed), at least insofar as it is not immediate in nature, and relies on the EEC, which failed to control the engine in the first place? This demands on actual events in the IPT locale, and taken in sum, they argue against a failure due to Fire.
In this way: Any fire would need time to act on the IPT bore. The more logical assumption is that the bearings (balls) wore beyond their ability to prevent axial (aft) movement, and the Drive Arm was pushed into the Stator Ring. The ten Radial Struts here, were under suspicion via AD targeting their Bolts on the case. They were to be inspected during Strip or borescope. The Splines, oddly enough, at this point, though worn, may not have actually caused the failure. The Splines were subject to inspection, but were just canaries in the mine; What caused the Spline wear also caused the Bearing wear, also caused the Oil Problem, etc.
So we take serious note of the AD's in the Burst, or we rely on The Manufacturer's claim that the Burst was caused by Oil Fire. It is more or less that simple, IMO.
It is an assumption that there was Stretch due excess Heat. Would not the Disc fail instantly even at in limit RPM once the Drive Arm fractured? Also, Contact of any description IPT/NGV Platform would be exactly simultaneous with aft movement of Shaft??
Given the AD's, and their warning of Metal/Metal with aftward drift, isn't the better assumption that the Disc Fractured after contact with Stationery Parts, melted, Disintegrated, and caused burst?? I see no need to entertain Fire, or Blade shear to explain this Engine Explosion. The simpler explanation is generally assumed to be the more likely cause, No?
Applying Occam, then, we can simplify the assumed failure to include no fire, no overspeed (save after fracture), and no need to index the Failure with cockpit data (displayed), at least insofar as it is not immediate in nature, and relies on the EEC, which failed to control the engine in the first place? This demands on actual events in the IPT locale, and taken in sum, they argue against a failure due to Fire.
In this way: Any fire would need time to act on the IPT bore. The more logical assumption is that the bearings (balls) wore beyond their ability to prevent axial (aft) movement, and the Drive Arm was pushed into the Stator Ring. The ten Radial Struts here, were under suspicion via AD targeting their Bolts on the case. They were to be inspected during Strip or borescope. The Splines, oddly enough, at this point, though worn, may not have actually caused the failure. The Splines were subject to inspection, but were just canaries in the mine; What caused the Spline wear also caused the Bearing wear, also caused the Oil Problem, etc.
So we take serious note of the AD's in the Burst, or we rely on The Manufacturer's claim that the Burst was caused by Oil Fire. It is more or less that simple, IMO.
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Good grief
Thanks DERG. It looks like a good read. I notice the paper releases the TRENT for Flight. Let us hope they mean TEST Flight. When modelling, it is precisely the novelty that Cannot be seen. Modelling relies on abstract Thought, it does not think, nor does it conclude. IMO. It is generally the "novelty" that kills when it strikes, having no follow on Fail safer. again, IMO.
Thanks DERG. It looks like a good read. I notice the paper releases the TRENT for Flight. Let us hope they mean TEST Flight. When modelling, it is precisely the novelty that Cannot be seen. Modelling relies on abstract Thought, it does not think, nor does it conclude. IMO. It is generally the "novelty" that kills when it strikes, having no follow on Fail safer. again, IMO.
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bearfoil:
How true.
There's a T-shirt somewhere that says " G*d laughs at numbers ". Not only in turbomachinery, but in AGW.
When modelling, it is precisely the novelty that Cannot be seen. Modelling relies on abstract Thought, it does not think, nor does it conclude.
There's a T-shirt somewhere that says " G*d laughs at numbers ". Not only in turbomachinery, but in AGW.
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DERG
A good find and good read !
Here is something that the FADEC/ECU didn't do on QF32's Trent 900 engine #2 six years after this study:
A three-speed model of normality was able to identify as novel an event which gave rise to diverging speeds prior to automatic shutdown of the engine on the test bed.
Humm, what happened?
A good find and good read !
Here is something that the FADEC/ECU didn't do on QF32's Trent 900 engine #2 six years after this study:
A three-speed model of normality was able to identify as novel an event which gave rise to diverging speeds prior to automatic shutdown of the engine on the test bed.
Humm, what happened?
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Bearfoil
My Quote:
In this post I was responding to another quote on how the IPT blades could have failed without physical contact with other neighboring components. It was not an attempt to explain the total failure, where it started and how it progressed.
But, in that you brought up the subject of the disc:
Take a look at the photos of the recovered section of the IPT disc in the ASTB report. In the fracture surface photo, note the structure close to the bore on the forward side and the shape of the bore surface forward to aft.. In the photo of the rear face of the disc, note how one turbine blade root seems firmly in place, but another has a significant gap present in the corresponding disc slot and there is no indication of metal to metal contact at the disc rim or blade slot area. Also note the ductile bend of the power arm drive where it is present.
Now think about something, what are the two elements required to permanently form or deform metal where the normal material ductility is less than 10%?
My Quote:
Assuming the disc began to stretch, because of overspeed and presence of higher than designed for temperatures in the bore area, the turbine blades could have started to unlatch at the tip shrouds.
But, in that you brought up the subject of the disc:
isn't the better assumption that the Disc Fractured after contact with Stationery Parts, melted, Disintegrated, and caused burst?? I see no need to entertain Fire, or Blade shear to explain this Engine Explosion.
Now think about something, what are the two elements required to permanently form or deform metal where the normal material ductility is less than 10%?
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Flapping Madly
Try this link, then click on the link to download the full report.
Investigation: AO-2010-089 - Inflight engine failure - Qantas, Airbus A380, VH-OQA, overhead Batam Island, Indonesia, 4 November 2010
Try this link, then click on the link to download the full report.
Investigation: AO-2010-089 - Inflight engine failure - Qantas, Airbus A380, VH-OQA, overhead Batam Island, Indonesia, 4 November 2010
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flapping madly
I'll send along a pdf in a moment.
Turbine D
I doubt there was fusing of the Metallic bits at the Rim (IPT). First, the speed at which they travel, and the relatively low mass they contain (relative to the Drive Arm) don't allow for time on station to effect a puddle. The Stator Vanes Platform describes a cylinder (barrel) with only its rim effacing the IPT Rim/Blades' roots. The Rim(s) are closer to one another than the Drive Arm/Stator Ring. Thus the Blades would leave, concurrently with the disintegration of the Platform (and its aft fixed Vanes), prior to DA melt. I feature the Drive Arm slipping aftward until the IP Rim contacts the NGV Platform. This conflict shatters the platform as the Blades unroot. The Drive Arm continues aft into the Stator Ring, where melting and Fracture occur simultaneously. Once fractured, the Wheel itself splits in threes, and blows out the case. Loss of Blades cause Stall (HPT)(Bang 1), and the blow out of the case causes the second "bang".
The metal deposition at the flaring Bore, comes from the melted remnants of the Drive Arm Join with the bearing sleeve. The "Foldback" ( of portions of the edges of the Drive Arm) have to do with your poser re: insufficiently ductile metal permanently deformed??
I'd have to say two elements needed would be "Heat, and Hammer".
We need to remember that the supports that mount the Stator Ring to the Case were a constant problem, vis a vis the fastening bolts. The bolts were chronically coming loose..A guess at their looseness would be dramatic vibration in this area.
I'll send along a pdf in a moment.
Turbine D
I doubt there was fusing of the Metallic bits at the Rim (IPT). First, the speed at which they travel, and the relatively low mass they contain (relative to the Drive Arm) don't allow for time on station to effect a puddle. The Stator Vanes Platform describes a cylinder (barrel) with only its rim effacing the IPT Rim/Blades' roots. The Rim(s) are closer to one another than the Drive Arm/Stator Ring. Thus the Blades would leave, concurrently with the disintegration of the Platform (and its aft fixed Vanes), prior to DA melt. I feature the Drive Arm slipping aftward until the IP Rim contacts the NGV Platform. This conflict shatters the platform as the Blades unroot. The Drive Arm continues aft into the Stator Ring, where melting and Fracture occur simultaneously. Once fractured, the Wheel itself splits in threes, and blows out the case. Loss of Blades cause Stall (HPT)(Bang 1), and the blow out of the case causes the second "bang".
The metal deposition at the flaring Bore, comes from the melted remnants of the Drive Arm Join with the bearing sleeve. The "Foldback" ( of portions of the edges of the Drive Arm) have to do with your poser re: insufficiently ductile metal permanently deformed??
I'd have to say two elements needed would be "Heat, and Hammer".
We need to remember that the supports that mount the Stator Ring to the Case were a constant problem, vis a vis the fastening bolts. The bolts were chronically coming loose..A guess at their looseness would be dramatic vibration in this area.
Last edited by bearfoil; 28th Jan 2011 at 22:08.
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Agreed
Yup..the thing tore itself apart. Maybe the fire lasted a second or a few, the dark stains on the wing structure could be oil mist or carbon soot from a fire. Unless we could get in there and smell it we don't know. But the tear on the drive arm looks like a plain tear. Amazing the thing did not continue to burn, against the odds I would guess.
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What I wanted you to look at in the photo, Figure 15, Page 21, was the fracture surface near the forward face of the disc (golden color) very close to the bore. enlarge it. Look at the stepped lines that have been created in that area and the directional orientation. It could be these lines represent plastic deformation (slips). You answered the question correctly, Heat and stress (rpm's) combined. It is the only way the drive arm could bend that much without snapping. Also, there is no sign of rubbing on the IPT disc rim, meaning this portion of the disk, at least did not contact the stator ID band behind it. My thought is the disk tore out of its fastening mechanism, at the 580 power drive arm bolt holes because of plastic deformation (stretching). Also, it seems there were 4 fractured pieces of the disc. The three that were not found went out over or under the fuselage to the right according to the exit trajectory sketch in the report. The found disc piece came out of the engine to the left based on where it was found according to the labeled map.
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Turbine D
Hi. From the larger (135 degree) piece of Turbine Wheel recovered, I note the lack of flange, (bolt area). Instead, there is what EASA called a circumferential Fracture in Edelweiss, Miami. So I conclude the Drive Arm remained intact forward of the Wheel bore where it fastens to the L shaped Bearing sleeve. The Shaft flange makes up the aft portion of the bolted together assembly. It resembles a sandwich, in section.
We have made note of the molten metal "plated" to the flaring portion of the Wheel bore, so melted metal is known, and the folded over remnant of bore indicates your sub-ductile peening of this area. Also, there is Metal "Spatter" mentioned in the ATSB report, located on the aft face of the Turbine wheel. Your note of the lack of heat rub at the rim demonstrates the lack of effacement with the Stator Platform, as the Platform effaces the Blade roots, not the rim of the IPT. Here we are again at "Push and Shove" of the IPT Blades out in the forward direction from their fir tree roots, as the Wheel slips backwards into the Plane of the Stator Platform. If we find a Blade from the IP Wheel, I think the effacement Blade to Platform will show, and may even show molten metal.
I've yet to look at the Steps in the Wheel. Am I looking for "Spiral" or "Radial" stepping?? While we are at it, please look at #16. The segment of NGV Platform facing the aft Rim of IPT shows clearly the tracks of circumferential contact at the effacement IPT Wheel Rim/NGV Platform. It has characteristics of patent wear, not critical failure. The outer surface of the NGV Platform and the edge of the Platform itself show where chaotic contact Blade/Platform may have separated all the Blades. Note the missing metal where the Blade roots contacted the Platform??
This may sound farfetched, but so is IPT Burst. In looking at the fracture face of the recovered wheel piece, I note a layered area sub surface, with the surface seemingly uniform above it. This obviously degraded area looks like patent damage to me. To You??
The trajectory of the found piece was obviously eastward. I have a problem with the "drawing" of the location of the missing pieces in the core, then out the case and "up". The origin of the pieces are shown above or below the longitudinal axis of the engine. If the piece, for instance, shown above the L/A was a part of the Wheel, it would not have exited to starboard. At this point in the core, its rotation is clockwise, and therefore it would have exited to port. Now this may be picky, but it is misleading. Also, no one knows for how long the pieces remained inside their circular prison, (case). They could have rolled around its perimeter and exited anywhere.
Hi. From the larger (135 degree) piece of Turbine Wheel recovered, I note the lack of flange, (bolt area). Instead, there is what EASA called a circumferential Fracture in Edelweiss, Miami. So I conclude the Drive Arm remained intact forward of the Wheel bore where it fastens to the L shaped Bearing sleeve. The Shaft flange makes up the aft portion of the bolted together assembly. It resembles a sandwich, in section.
We have made note of the molten metal "plated" to the flaring portion of the Wheel bore, so melted metal is known, and the folded over remnant of bore indicates your sub-ductile peening of this area. Also, there is Metal "Spatter" mentioned in the ATSB report, located on the aft face of the Turbine wheel. Your note of the lack of heat rub at the rim demonstrates the lack of effacement with the Stator Platform, as the Platform effaces the Blade roots, not the rim of the IPT. Here we are again at "Push and Shove" of the IPT Blades out in the forward direction from their fir tree roots, as the Wheel slips backwards into the Plane of the Stator Platform. If we find a Blade from the IP Wheel, I think the effacement Blade to Platform will show, and may even show molten metal.
I've yet to look at the Steps in the Wheel. Am I looking for "Spiral" or "Radial" stepping?? While we are at it, please look at #16. The segment of NGV Platform facing the aft Rim of IPT shows clearly the tracks of circumferential contact at the effacement IPT Wheel Rim/NGV Platform. It has characteristics of patent wear, not critical failure. The outer surface of the NGV Platform and the edge of the Platform itself show where chaotic contact Blade/Platform may have separated all the Blades. Note the missing metal where the Blade roots contacted the Platform??
This may sound farfetched, but so is IPT Burst. In looking at the fracture face of the recovered wheel piece, I note a layered area sub surface, with the surface seemingly uniform above it. This obviously degraded area looks like patent damage to me. To You??
The trajectory of the found piece was obviously eastward. I have a problem with the "drawing" of the location of the missing pieces in the core, then out the case and "up". The origin of the pieces are shown above or below the longitudinal axis of the engine. If the piece, for instance, shown above the L/A was a part of the Wheel, it would not have exited to starboard. At this point in the core, its rotation is clockwise, and therefore it would have exited to port. Now this may be picky, but it is misleading. Also, no one knows for how long the pieces remained inside their circular prison, (case). They could have rolled around its perimeter and exited anywhere.
Last edited by bearfoil; 29th Jan 2011 at 00:31.
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Hazelnuts39
Sorry for taking so long. By "baseline" I mean common rated thrust, in this instance Maximum Continuous Thrust for the 900. Upgrades are for thrust that is available short term? So here, at burst, the 972 was not performing any different than a 900 would be. Maximum continuous thrust in the climb, or some lesser value?? What is different? The DEP makes available for short periods augmented thrust from the same core. The restriction on this excess thrust is the crux of the discussion, imo. Either it is a proven design, or it is not, and if not, it has no place bolted to a wing, only to a stand. So my question is as before? Where does this rather substantial thrust come from? The same Core? At the same RPMs?? This implies a merely "derated" 900, and an "augmented" 972?? There is to me a discrepancy.
Sorry for taking so long. By "baseline" I mean common rated thrust, in this instance Maximum Continuous Thrust for the 900. Upgrades are for thrust that is available short term? So here, at burst, the 972 was not performing any different than a 900 would be. Maximum continuous thrust in the climb, or some lesser value?? What is different? The DEP makes available for short periods augmented thrust from the same core. The restriction on this excess thrust is the crux of the discussion, imo. Either it is a proven design, or it is not, and if not, it has no place bolted to a wing, only to a stand. So my question is as before? Where does this rather substantial thrust come from? The same Core? At the same RPMs?? This implies a merely "derated" 900, and an "augmented" 972?? There is to me a discrepancy.
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The engine is certified right up to 84 so the 72 version should have been "a walk in the park" The thrust comes from the fuel and that depends on the central processor.
"Either it is a proven design, or it is not, and if not, it has no place bolted to a wing, only to a stand."
This 900 engine was designed to be experimental in service: whole raft of documentation tells us just that. Of course it had no place on a civil aircraft. No probs in military applics: see here
http://www.robots.ox.ac.uk/~davidc/p...eaerospace.pdf
Hell of a lot of work to do by RR and Airbus. Flight Aware has not published any flight times on the QFA12 service, probably cause they are only using minimum throttle and carry less payload. Not all the flights are A388s either, my guess is they send the B74s when they need to carry a real load. No wonder the Qantas B74s are munching engines, the are working hard!
From post#317:
"The focus of ACARE was to set a strategic research agenda aimed at meeting the environmental challenges set out in the European Aeronautics Vision for 2020. As a result, Rolls Royce (RR) and other companies in the aeronautical industry were faced with challenges including reducing fuel consumption and CO2 emissions by 50%, reducing external noise by 50%, reducing NOX emissions by 80% and reducing the environmental impact of manufacture, maintenance and disposal of aircraft-related products. At the forefront of responding to ACAREs pan-European research challenge is the ability of companies such as RR to investigate, through high-performance computing (HPC)-based simulations, innovative methods of design and operability of aircraft products."
A roundup flyer sheet:
Systems Analysis, Modelling and Prediction Group
Thats the design goal. Therein lies the clue to the T900 and its woes.
TURBINE D Yes I see the part. That looks like it was in a plastic state when it parted. Yes a fire.
When I was trawling through the internet I came across a very few references fom the USA to "modelling", I mean design modelling as applied to aerosapce engine.
The few that I did find were mainly published by NASA.
They were VERY conservative and made it clear that "a model" was just that "a model".
Would I be correct in thinking that the USA prefers the known to the unkown when it comes to aerospace turbofans?
"Either it is a proven design, or it is not, and if not, it has no place bolted to a wing, only to a stand."
This 900 engine was designed to be experimental in service: whole raft of documentation tells us just that. Of course it had no place on a civil aircraft. No probs in military applics: see here
http://www.robots.ox.ac.uk/~davidc/p...eaerospace.pdf
Hell of a lot of work to do by RR and Airbus. Flight Aware has not published any flight times on the QFA12 service, probably cause they are only using minimum throttle and carry less payload. Not all the flights are A388s either, my guess is they send the B74s when they need to carry a real load. No wonder the Qantas B74s are munching engines, the are working hard!
From post#317:
"The focus of ACARE was to set a strategic research agenda aimed at meeting the environmental challenges set out in the European Aeronautics Vision for 2020. As a result, Rolls Royce (RR) and other companies in the aeronautical industry were faced with challenges including reducing fuel consumption and CO2 emissions by 50%, reducing external noise by 50%, reducing NOX emissions by 80% and reducing the environmental impact of manufacture, maintenance and disposal of aircraft-related products. At the forefront of responding to ACAREs pan-European research challenge is the ability of companies such as RR to investigate, through high-performance computing (HPC)-based simulations, innovative methods of design and operability of aircraft products."
A roundup flyer sheet:
Systems Analysis, Modelling and Prediction Group
Thats the design goal. Therein lies the clue to the T900 and its woes.
TURBINE D Yes I see the part. That looks like it was in a plastic state when it parted. Yes a fire.
When I was trawling through the internet I came across a very few references fom the USA to "modelling", I mean design modelling as applied to aerosapce engine.
The few that I did find were mainly published by NASA.
They were VERY conservative and made it clear that "a model" was just that "a model".
Would I be correct in thinking that the USA prefers the known to the unkown when it comes to aerospace turbofans?
Last edited by DERG; 29th Jan 2011 at 09:42. Reason: syntax
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I would think that the 'baseline' is the variant with the highest thrust rating, i.e. the RB211-Trent 980-84, sealevel static TO thrust rating 84,098 lbs, flat-rated to ISA+15C. The thrust levels of that rating must be achieved without exceeding operating limits of RPM and TGT. The manufacturer selects rating(s) so that they they have some margin relative to the operating limits. The lesser ratings are 'derates' and have greater margins than the highest rating. In TO ratings Trent 900 the various ratings are shown at the flat-rated temperature. The dashed line shows schematically the thrust corresponding to the operating limits, whichever is most limiting. The line is drawn arbitrarily, because the documents don't tell us where it lies. It's actual location will be different from engine to engine, and the margin will reduce as the engine deteriorates during its service life.
Prior to certification, proof of integrity of the engine operating at the declared operating limits must be provided by analysis, component testing and, finally, by a 150 hr endurance test which represents an accelerated life cycle of the engine. 'Modelling' is a design tool, not proof of compliance with airworthiness standards.
Prior to certification, proof of integrity of the engine operating at the declared operating limits must be provided by analysis, component testing and, finally, by a 150 hr endurance test which represents an accelerated life cycle of the engine. 'Modelling' is a design tool, not proof of compliance with airworthiness standards.
Last edited by Jetdriver; 29th Jan 2011 at 19:03.
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Another NOVELTY
The engine with a 70 cycle lifespan. Bettya that was not in the sales presentation to Quantas! Thats the life RR gives the 972 in Qantas operations.
Some of you may think that a bird strike is a "novelty event"..
Well this author does too...been waiting for this!
http://www.eng.ox.ac.uk/samp/pubs/clifton_transfer.pdf
Sleep Well!
Some of you may think that a bird strike is a "novelty event"..
Well this author does too...been waiting for this!
http://www.eng.ox.ac.uk/samp/pubs/clifton_transfer.pdf
Sleep Well!
Last edited by DERG; 29th Jan 2011 at 10:53. Reason: add link, spelling
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Nomenclature. It is important I understand your description. A "Baseline" machine to me is its original "Design". One seldom starts with the nephew and progresses toward the Grand Uncle. So it seems to me counterintuitive in the least.
I note your numbers and explanations, and I believe your representation of the 900 family. So I would ask, if the most powerful powerplant has the same construction, core, wheels and limits (Temperature and RPM), as the least powerful, then this appears rather strange. Airbus "found" 6k lbs. of extra weight on the whale, necessitating more thrust available at Take-off at MGW. The result was the 972, I believe, a hurried iteration with a new Data Entry Plug. Why on Earth develop an engine with X Thrust, then derate (make unavailable) its Power??
Can you help me out with a more basic explanation, then?
thanks
bear
Nomenclature. It is important I understand your description. A "Baseline" machine to me is its original "Design". One seldom starts with the nephew and progresses toward the Grand Uncle. So it seems to me counterintuitive in the least.
I note your numbers and explanations, and I believe your representation of the 900 family. So I would ask, if the most powerful powerplant has the same construction, core, wheels and limits (Temperature and RPM), as the least powerful, then this appears rather strange. Airbus "found" 6k lbs. of extra weight on the whale, necessitating more thrust available at Take-off at MGW. The result was the 972, I believe, a hurried iteration with a new Data Entry Plug. Why on Earth develop an engine with X Thrust, then derate (make unavailable) its Power??
Can you help me out with a more basic explanation, then?
thanks
bear
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Bear
Howdy!
Airbus found 6 metric tonnes of over design mass on the airframe which is closer to 13 000lbs
Greets!
Hey take a look at this about half way through you can play with the cross section of the shafts...amazing torsion these are under...amzn.
http://www.eng.ox.ac.uk/thermofluids...453,18,Heating from Seals
Airbus found 6 metric tonnes of over design mass on the airframe which is closer to 13 000lbs
Greets!
Hey take a look at this about half way through you can play with the cross section of the shafts...amazing torsion these are under...amzn.
http://www.eng.ox.ac.uk/thermofluids...453,18,Heating from Seals
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Originally Posted by bearfoil
Why on Earth develop an engine with X Thrust, then derate (make unavailable) its Power??
EDIT::
a hurried iteration with a new Data Entry Plug.
regards,
HN39
Last edited by HazelNuts39; 29th Jan 2011 at 15:29.