QANTAS A380 Uncontained failure.
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If the engine had expolded over Manhattan I bet the FAA would be a little more vigorous in giving out the all OK tickets. CNN would have made a few noises.
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Regulations & Guidance Circulars
Trent 972
If you refer to the master certification document:
PART 33—AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES
You will note under "vibration", it basically states (my wording, not verbatim) that adequate testing must be done to demonstrate vibration is not a problem. So then, the circular about this subject is issued to "guide" the requester through the process of testing for vibration during the certification process as there may have been many questions in past and present regarding what is acceptable to the FAA. The circular implies "Here is a way to accomplish vibration testing that is acceptable to us, but there are other way that may be acceptable as well." It is a unhappy day to have spent $1M or $2M on an engine test to only learn it didn't meet the certification criteria in the FAA's eyes.
Turbine D
The Key Document Faa A.c. 33.63-1, then perhaps you should also give consideration to paragraph 2b. on the first page. ie.
PART 33—AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES
You will note under "vibration", it basically states (my wording, not verbatim) that adequate testing must be done to demonstrate vibration is not a problem. So then, the circular about this subject is issued to "guide" the requester through the process of testing for vibration during the certification process as there may have been many questions in past and present regarding what is acceptable to the FAA. The circular implies "Here is a way to accomplish vibration testing that is acceptable to us, but there are other way that may be acceptable as well." It is a unhappy day to have spent $1M or $2M on an engine test to only learn it didn't meet the certification criteria in the FAA's eyes.
Turbine D
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Thankyou Turbine D.
Please provide the documents to prove that
Was NOT done.
I would also like to see the document from the FAA that informs
After I've had a chance to read them, I'll be more than happy to discuss the ramifications.
Please provide the documents to prove that
....that adequate testing must be done to demonstrate vibration is not a problem.
I would also like to see the document from the FAA that informs
...it didn't meet the certification criteria in the FAA's eyes.
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Trent 972 - there isn't. Overactive imaginations are running free.
Why all this discussion on FAA on a European designed engine fitted to an Australian aircraft anyway?
DERG
Refer to the Operating Instructions for information on approved oil specifications for the Trent 900 old chap.
Why all this discussion on FAA on a European designed engine fitted to an Australian aircraft anyway?
DERG
Refer to the Operating Instructions for information on approved oil specifications for the Trent 900 old chap.
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Shoulder to Shoulder
"Why all this discussion on FAA on a European designed engine fitted to an Australian aircraft anyway?"
This might be a dog eat dog industry Shell but when it comes to life and limb we are united.
This might be a dog eat dog industry Shell but when it comes to life and limb we are united.
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Trent 972
Electronic Code of Federal Regulations:
From this document:
Subpart E—Design and Construction; Turbine Aircraft Engines
§ 33.63 Vibration.
Each engine must be designed and constructed to function throughout its declared flight envelope and operating range of rotational speeds and power/thrust, without inducing excessive stress in any engine part because of vibration and without imparting excessive vibration forces to the aircraft structure.
Subpart F—Block Tests; Turbine Aircraft Engines
§ 33.83 Vibration test.
(a) Each engine must undergo vibration surveys to establish that the vibration characteristics of those components that may be subject to mechanically or aerodynamically induced vibratory excitations are acceptable throughout the declared flight envelope. The engine surveys shall be based upon an appropriate combination of experience, analysis, and component test and shall address, as a minimum, blades, vanes, rotor discs, spacers, and rotor shafts.
(b) The surveys shall cover the ranges of power or thrust, and both the physical and corrected rotational speeds for each rotor system, corresponding to operations throughout the range of ambient conditions in the declared flight envelope, from the minimum rotational speed up to 103 percent of the maximum physical and corrected rotational speed permitted for rating periods of two minutes or longer, and up to 100 percent of all other permitted physical and corrected rotational speeds, including those that are overspeeds. If there is any indication of a stress peak arising at the highest of those required physical or corrected rotational speeds, the surveys shall be extended sufficiently to reveal the maximum stress values present, except that the extension need not cover more than a further 2 percentage points increase beyond those speeds.
(c) Evaluations shall be made of the following:
(1) The effects on vibration characteristics of operating with scheduled changes (including tolerances) to variable vane angles, compressor bleeds, accessory loading, the most adverse inlet air flow distortion pattern declared by the manufacturer, and the most adverse conditions in the exhaust duct(s); and
(2) The aerodynamic and aeromechanical factors which might induce or influence flutter in those systems susceptible to that form of vibration.
(d) Except as provided by paragraph (e) of this section, the vibration stresses associated with the vibration characteristics determined under this section, when combined with the appropriate steady stresses, must be less than the endurance limits of the materials concerned, after making due allowances for operating conditions for the permitted variations in properties of the materials. The suitability of these stress margins must be justified for each part evaluated. If it is determined that certain operating conditions, or ranges, need to be limited, operating and installation limitations shall be established.
(e) The effects on vibration characteristics of excitation forces caused by fault conditions (such as, but not limited to, out-of balance, local blockage or enlargement of stator vane passages, fuel nozzle blockage, incorrectly schedule compressor variables, etc.) shall be evaluated by test or analysis, or by reference to previous experience and shall be shown not to create a hazardous condition.
(f) Compliance with this section shall be substantiated for each specific installation configuration that can affect the vibration characteristics of the engine. If these vibration effects cannot be fully investigated during engine certification, the methods by which they can be evaluated and methods by which compliance can be shown shall be substantiated and defined in the installation instructions required by §33.5.
[Doc. No. 28107, 61 FR 28433, June 4, 1996]
Hope this helps...
Turbine D
Please provide the documents to prove that
Quote:
....that adequate testing must be done to demonstrate vibration is not a problem.
Quote:
....that adequate testing must be done to demonstrate vibration is not a problem.
From this document:
Subpart E—Design and Construction; Turbine Aircraft Engines
§ 33.63 Vibration.
Each engine must be designed and constructed to function throughout its declared flight envelope and operating range of rotational speeds and power/thrust, without inducing excessive stress in any engine part because of vibration and without imparting excessive vibration forces to the aircraft structure.
Subpart F—Block Tests; Turbine Aircraft Engines
§ 33.83 Vibration test.
(a) Each engine must undergo vibration surveys to establish that the vibration characteristics of those components that may be subject to mechanically or aerodynamically induced vibratory excitations are acceptable throughout the declared flight envelope. The engine surveys shall be based upon an appropriate combination of experience, analysis, and component test and shall address, as a minimum, blades, vanes, rotor discs, spacers, and rotor shafts.
(b) The surveys shall cover the ranges of power or thrust, and both the physical and corrected rotational speeds for each rotor system, corresponding to operations throughout the range of ambient conditions in the declared flight envelope, from the minimum rotational speed up to 103 percent of the maximum physical and corrected rotational speed permitted for rating periods of two minutes or longer, and up to 100 percent of all other permitted physical and corrected rotational speeds, including those that are overspeeds. If there is any indication of a stress peak arising at the highest of those required physical or corrected rotational speeds, the surveys shall be extended sufficiently to reveal the maximum stress values present, except that the extension need not cover more than a further 2 percentage points increase beyond those speeds.
(c) Evaluations shall be made of the following:
(1) The effects on vibration characteristics of operating with scheduled changes (including tolerances) to variable vane angles, compressor bleeds, accessory loading, the most adverse inlet air flow distortion pattern declared by the manufacturer, and the most adverse conditions in the exhaust duct(s); and
(2) The aerodynamic and aeromechanical factors which might induce or influence flutter in those systems susceptible to that form of vibration.
(d) Except as provided by paragraph (e) of this section, the vibration stresses associated with the vibration characteristics determined under this section, when combined with the appropriate steady stresses, must be less than the endurance limits of the materials concerned, after making due allowances for operating conditions for the permitted variations in properties of the materials. The suitability of these stress margins must be justified for each part evaluated. If it is determined that certain operating conditions, or ranges, need to be limited, operating and installation limitations shall be established.
(e) The effects on vibration characteristics of excitation forces caused by fault conditions (such as, but not limited to, out-of balance, local blockage or enlargement of stator vane passages, fuel nozzle blockage, incorrectly schedule compressor variables, etc.) shall be evaluated by test or analysis, or by reference to previous experience and shall be shown not to create a hazardous condition.
(f) Compliance with this section shall be substantiated for each specific installation configuration that can affect the vibration characteristics of the engine. If these vibration effects cannot be fully investigated during engine certification, the methods by which they can be evaluated and methods by which compliance can be shown shall be substantiated and defined in the installation instructions required by §33.5.
[Doc. No. 28107, 61 FR 28433, June 4, 1996]
Hope this helps...
Turbine D
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Shell Management
1. It is believed that the FAA & EASA have similar requirements on aircraft and aircraft engine certifications. Both agencies talk to one another and accept back and forth certifications depending on where the aircraft/engine is being designed and built. In the case of the A-380/Trent 900 series, the ball is in EASA's court. In the case of the A-380/GP7200, EASA certified the aircraft, FAA certified the engine as it was developed by GE/PWA in the US.
2. The aircraft is not "Australian", it is of European origin, an Australian airline bought the package (A-380/Trent 900 series) as did other airlines.
3. The FAA accepted the certification packages, but probably depending totally on the EASA's certifications without much ado. No US airlines have purchased A-380/Trent 900 series aircraft. However, for flights into and out of US airports, a comparable FAA certification must exist or there wouldn't be Sydney to LAX flights.
4. Living in the US, it is easy to obtain FAA certification requirements as presented in previous posts. EASA certification requirements are not so easy per-se, perhaps you might contribute similar EASA documents for comparison.
5. The Trent 972 failure on the Qantas A-380 was not a ho-hum event. Anytime a disc bursts out of the engine, it is life threatening. And so, how did this happen? Was it preventable? Were problems identified, leading to this catastrophic event, not fully addressed? Why is there disassociation between what happened on Qantas verses seemingly prior related problems which were either partially addressed or not addressed at all at the time? What were the roles and responsibilities of the various players involved? How have they met their responsibilities?
6. Isn't this what the Tech Log is all about, exploring the possibilities?
So what oils are approved for the Trent 900 series engines? It isn't clear in the Type Certification Document.
Turbine D
Why all this discussion on FAA on a European designed engine fitted to an Australian aircraft anyway?
2. The aircraft is not "Australian", it is of European origin, an Australian airline bought the package (A-380/Trent 900 series) as did other airlines.
3. The FAA accepted the certification packages, but probably depending totally on the EASA's certifications without much ado. No US airlines have purchased A-380/Trent 900 series aircraft. However, for flights into and out of US airports, a comparable FAA certification must exist or there wouldn't be Sydney to LAX flights.
4. Living in the US, it is easy to obtain FAA certification requirements as presented in previous posts. EASA certification requirements are not so easy per-se, perhaps you might contribute similar EASA documents for comparison.
5. The Trent 972 failure on the Qantas A-380 was not a ho-hum event. Anytime a disc bursts out of the engine, it is life threatening. And so, how did this happen? Was it preventable? Were problems identified, leading to this catastrophic event, not fully addressed? Why is there disassociation between what happened on Qantas verses seemingly prior related problems which were either partially addressed or not addressed at all at the time? What were the roles and responsibilities of the various players involved? How have they met their responsibilities?
6. Isn't this what the Tech Log is all about, exploring the possibilities?
Refer to the Operating Instructions for information on approved oil specifications for the Trent 900 old chap.
Turbine D
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Originally Posted by Turbine D
And so, how did this happen? Was it preventable? Were problems identified, leading to this catastrophic event, not fully addressed? Why is there disassociation between what happened on Qantas verses seemingly prior related problems which were either partially addressed or not addressed at all at the time? What were the roles and responsibilities of the various players involved? How have they met their responsibilities?
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HN39
I wouldn´t be too sure that within the "Brotherhood of PPRuners" there are not some members that have the right answers at hand.
But to use and rephrase your words:
To ask this questions is one thing. To answer them in public might be of such an extend to the players involved, that it is wiser to handle the case with care and caution.
As I understand the ongoing discussion. Primary goal is safety. As an - important - side effect, we all want to hear from the "officials" what the root cause of that QF 32 desaster was. Well, we can wait.
But to use and rephrase your words:
To ask this questions is one thing. To answer them in public might be of such an extend to the players involved, that it is wiser to handle the case with care and caution.
As I understand the ongoing discussion. Primary goal is safety. As an - important - side effect, we all want to hear from the "officials" what the root cause of that QF 32 desaster was. Well, we can wait.
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Originally Posted by Turbine D
it is easy to obtain FAA certification requirements as presented in previous posts. EASA certification requirements are not so easy per-se
EASA Home Page
CS-E
Trent TCDS E.012
Last edited by HazelNuts39; 30th Jan 2011 at 16:57.
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The Certificate is based on Data. Ignored or unaware, the applicant needs to supply this data. It is forthcoming. The bottom line is Spline Wear. The engine had an oil fire in test. The engine exhibited some anomalous vibration and resonant transients that beat it to a pulp over shorter than allowable (and Certificated) time.
These are the issues, and the rest is corn soup. Who expects a problem of this magnitude to casually enter the Public Domain?? Nice discussion, though.
These are the issues, and the rest is corn soup. Who expects a problem of this magnitude to casually enter the Public Domain?? Nice discussion, though.
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Engine oil
Turbine D has drawn a little heat for asking some questions, in the last few posts above. But nonetheless one of Turbine D's questions was of considerable interest to me, that regarding the specifications of the [QF32] engine oil. And Turbine D asked that question directly to Shell Management, whom I think we are entitled to assume has the background to answer it more fully than he did. The exchange:
Question:
Answer, by Shell Mgmt, addressed to DERG:
Well, I see now the question was DERG's, restated by Turbine D. I find the answer to be a bit circular, at least to me in my ignorance. The AC Captain who posted in the original oil thread here that he'd been down the AC oil road once before and never wanted to go down it again has my full sympathy. I too have been down the oil road with the oil manufacturers. But here goes, yet again and ever hopeful:
1. The type certification document says that the oil shall be as specified by the manufacturer. [I omit mention of the reams I read as to which manufacturer [AC or engine], and as to whom holds the certificate, and whom incorporates it by reference; not to mention where the oil may be obtained.]
2. The AC manufacturer now says that MJO II or MJO 294 may be used; the AC QF32 was shipped with MJO II installed; the failed engine appears to have been using MJO 294 [I may have to correct the "memory item" 294 on edit]. When the changeover occurred may have been at the 3-year repair point, but I did not see this published anywhere. Some or all of the other engines on QF32 continued with the originally installed type of oil.
3. Now comes the problem. Perhaps the Operating Instructions contain the actual specs of the oil, which is only identified by name in the public documents. [My deduction at the moment is that the A380 Operating Instructions either are distributed need-to-know basis only, or do not yet exist.]
4. Of course, the Mobil (or ExxonMobil, which may or may not be the same thing) website for oil contains the specifications for the oil in question. The problem is, these voluminous specifications are next to useless in the jet engine context. I give one example at #5 and 6 ff:
5. Viscosity of the hot oil: 5 centistokes at 100-degrees Centigrade. Well, I don't think the viscosity at 100-C has been of any interest since pressure radiator caps were added to water-cooled automobile engines sometime in the 1930s.
6. What are we given instead: MJO-xxx (whatever) is provided with extended range viscosity stabilizers. Give me a break. What is the viscosity of these two oils at 180-C and 196-C?
7. On to another question. What is the base stock of these two oil types? Well, for MJO II it is fairly clearly identified as a highly refined mineral oil base. Okay, I'll accept that as an answer. But for MJO-294, the situation become murky indeed. It was identified on a document posted here [at least of quasi-official standing, I will look it up] as being an HPC oil. However, I located a MIL spec discussion in which MJO-294 [number from memory, will edit] is identified as an SPC oil, which whatever it is, is not an HPC oil.
8. I think the MJO-294 must be also a highly refined mineral oil base, but with the addition of PG additives, but what do I know? ExxonMobil describes it as an "advanced oil", IIRC.
9. The question of whether both these oils have a mineral oil base bears on two questions. One is the question of lubricity, at which the mineral oils excel. The other is the viscosity buildup that occurs to such oils when the evaporation rate removes the lighter fractions preferentially, and "topping up" is frequent. It will be frequent if the operation is at the specification operating limit temperature for evaporation-- a 12-hour flight to LAX would consume half the contents of the engine oil reservoir.
10. ExxonMobil have an HPC oil under development. It is unobtainable in the US as of December, if it is available anywhere.
11. I get the feeling there is a desire to have the oil last between major off-wing inspections/overhauls. Perhaps this is because MJO-294 (again, number subject to edit) is a potent orthophosphate insecticide. For crying out loud, even the US tv police sitcom "Castle" took notice of this within the last month. Where do these people find these things out, let alone accurately? [That's not a question that needs an answer.]
Shell Management, I assume you must know the answers to the questions and uncertainties I discussed above: Meaningful viscosity data, base oil and expected T-972 oil temps enroute LAX as it affects viscosity buildup due evaporation on the long-term hand, and viscosity loss at high temp in new oil on the short-term hand-- these are the uncertainties which I think need to be known. It would be helpful to know your views on oil change intervals. Your views on whether Engine #2 might have been operating with an oil likely to have insufficient lubricity would also be helpful.
Hopefully you will not be constrained in your position at Shell from discussing Exxon products. Or you might prefer to make a discussion from the standpoint of Castrol products, which perhaps are more likely to have been used by RR in the development of the engine. Thanks.
Question:
So what oils are approved for the Trent 900 series engines? It isn't clear in the Type Certification Document.
DERG
Refer to the Operating Instructions for information on approved oil specifications for the Trent 900 old chap.
Refer to the Operating Instructions for information on approved oil specifications for the Trent 900 old chap.
1. The type certification document says that the oil shall be as specified by the manufacturer. [I omit mention of the reams I read as to which manufacturer [AC or engine], and as to whom holds the certificate, and whom incorporates it by reference; not to mention where the oil may be obtained.]
2. The AC manufacturer now says that MJO II or MJO 294 may be used; the AC QF32 was shipped with MJO II installed; the failed engine appears to have been using MJO 294 [I may have to correct the "memory item" 294 on edit]. When the changeover occurred may have been at the 3-year repair point, but I did not see this published anywhere. Some or all of the other engines on QF32 continued with the originally installed type of oil.
3. Now comes the problem. Perhaps the Operating Instructions contain the actual specs of the oil, which is only identified by name in the public documents. [My deduction at the moment is that the A380 Operating Instructions either are distributed need-to-know basis only, or do not yet exist.]
4. Of course, the Mobil (or ExxonMobil, which may or may not be the same thing) website for oil contains the specifications for the oil in question. The problem is, these voluminous specifications are next to useless in the jet engine context. I give one example at #5 and 6 ff:
5. Viscosity of the hot oil: 5 centistokes at 100-degrees Centigrade. Well, I don't think the viscosity at 100-C has been of any interest since pressure radiator caps were added to water-cooled automobile engines sometime in the 1930s.
6. What are we given instead: MJO-xxx (whatever) is provided with extended range viscosity stabilizers. Give me a break. What is the viscosity of these two oils at 180-C and 196-C?
7. On to another question. What is the base stock of these two oil types? Well, for MJO II it is fairly clearly identified as a highly refined mineral oil base. Okay, I'll accept that as an answer. But for MJO-294, the situation become murky indeed. It was identified on a document posted here [at least of quasi-official standing, I will look it up] as being an HPC oil. However, I located a MIL spec discussion in which MJO-294 [number from memory, will edit] is identified as an SPC oil, which whatever it is, is not an HPC oil.
8. I think the MJO-294 must be also a highly refined mineral oil base, but with the addition of PG additives, but what do I know? ExxonMobil describes it as an "advanced oil", IIRC.
9. The question of whether both these oils have a mineral oil base bears on two questions. One is the question of lubricity, at which the mineral oils excel. The other is the viscosity buildup that occurs to such oils when the evaporation rate removes the lighter fractions preferentially, and "topping up" is frequent. It will be frequent if the operation is at the specification operating limit temperature for evaporation-- a 12-hour flight to LAX would consume half the contents of the engine oil reservoir.
10. ExxonMobil have an HPC oil under development. It is unobtainable in the US as of December, if it is available anywhere.
11. I get the feeling there is a desire to have the oil last between major off-wing inspections/overhauls. Perhaps this is because MJO-294 (again, number subject to edit) is a potent orthophosphate insecticide. For crying out loud, even the US tv police sitcom "Castle" took notice of this within the last month. Where do these people find these things out, let alone accurately? [That's not a question that needs an answer.]
Shell Management, I assume you must know the answers to the questions and uncertainties I discussed above: Meaningful viscosity data, base oil and expected T-972 oil temps enroute LAX as it affects viscosity buildup due evaporation on the long-term hand, and viscosity loss at high temp in new oil on the short-term hand-- these are the uncertainties which I think need to be known. It would be helpful to know your views on oil change intervals. Your views on whether Engine #2 might have been operating with an oil likely to have insufficient lubricity would also be helpful.
Hopefully you will not be constrained in your position at Shell from discussing Exxon products. Or you might prefer to make a discussion from the standpoint of Castrol products, which perhaps are more likely to have been used by RR in the development of the engine. Thanks.
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Old Engineer
Thanks for that R and R outage away from the tough stuff. I have to say that my question to Shell would have been in the circumstances where I had him physically up agin a wall.
The oil sellers annoy me. I have done a fair bit of tribology and the best lubricant on the planet is nature's olive oil.
You can "crack" imineral oil all you want..comes nowhere near the mighty olive. I am so glad I am nowhere near Shell, I am very short tempered.
The oil sellers annoy me. I have done a fair bit of tribology and the best lubricant on the planet is nature's olive oil.
You can "crack" imineral oil all you want..comes nowhere near the mighty olive. I am so glad I am nowhere near Shell, I am very short tempered.
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Approved Jet Oils per SAE 5780
Old Engineer
In this presentation, there is a table listing the approved oils meeting SAE 5780 specification requirements, BP, Shell & Exxon/Mobil.
http://isoclean.net/uploads/GE_turbi..._pres_STLE.pdf
By the way, are roller bearings more sensitive to oil viscosity changes at higher temperatures than ball bearings?
In this presentation, there is a table listing the approved oils meeting SAE 5780 specification requirements, BP, Shell & Exxon/Mobil.
http://isoclean.net/uploads/GE_turbi..._pres_STLE.pdf
By the way, are roller bearings more sensitive to oil viscosity changes at higher temperatures than ball bearings?
Last edited by Jetdriver; 31st Jan 2011 at 05:23.
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Oh dear. Some people are jumping to very big conclusions and suffering from homo-erotic based fantasies too.
BTW the Operating Instructions are for the Trent not the A380.
BTW the Operating Instructions are for the Trent not the A380.
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TurbineD
When you say:
Are you using the 'royal we'?
If you R_E_A_D the thread tou will notice Old Engineer wrote:
When you say:
Shell Management
Quote:
the Operating Instructions are for the Trent not the A380.
Thanks for this information, we knew this.
Quote:
the Operating Instructions are for the Trent not the A380.
Thanks for this information, we knew this.
Are you using the 'royal we'?
If you R_E_A_D the thread tou will notice Old Engineer wrote:
3. Now comes the problem. Perhaps the Operating Instructions contain the actual specs of the oil, which is only identified by name in the public documents. [My deduction at the moment is that the A380 Operating Instructions either are distributed need-to-know basis only, or do not yet exist.]
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Shell Management
If you go to the Spotters Forum and look at the first thread, it contains this:
Spotters it has to be said are not always welcome in the professional forums, and for good reason, because some of them make a nuisance of themselves and upset the pros and natives.
Need more be said?
Are you using the 'royal we'?
If you R_E_A_D the thread tou will notice Old Engineer wrote:
If you R_E_A_D the thread tou will notice Old Engineer wrote:
Spotters it has to be said are not always welcome in the professional forums, and for good reason, because some of them make a nuisance of themselves and upset the pros and natives.
Need more be said?
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TCDS - Trent 900 Engine Series
I have a question on the TCDS:
http://www.easa.europa.eu/certificat...4-24052007.pdf
On Page 4, Item 4 - Equivalent Safety Findings:
What exactly does this mean? Did the engine not pass this test? Was a subsequent test performed and it passed? Was the test waived?
What is the opinion of this particular item?
http://www.easa.europa.eu/certificat...4-24052007.pdf
On Page 4, Item 4 - Equivalent Safety Findings:
- JAR-E740 150 Hour Endurance Test
What exactly does this mean? Did the engine not pass this test? Was a subsequent test performed and it passed? Was the test waived?
What is the opinion of this particular item?