DERG

I don't disagree, but not only is your view a bit simplistic, there is question whether an Oil Fire caused the burst.

For instance, as old engineer writes, the Oil's temp rises gradually, and not even to flash point (by measure at the scavenge inlets). Now this doesn't preclude Fire, but, an Oil Fire by definition is an oil fed fire, and there seems to be no Oil missing from the system.

Oil may have accumulated as solids over time (as coke) in critical locales, but no theory of actual fuel for fire is offered. The authority, ATSB, has offered that an Oil Fire "may have initiated a sequence that resulted in Uncontained release", etc. But the theory of bearing heat obtains just as well.

What is the mechanism for fire to be located in the "Annulus" between HPT and IPT? How did the fire heat the Drive Arm from its aft portion (Not known), when the fire was located on the forward side of the disc?

Question. On Figure 8, at the Fan, take note of Blades that appear to have been damaged. Notice two blades past the spinner's top, at ~10 o'clock. Illusion?

DERG

In prior posts we discussed the lack of disclosure by RR and LuftyMx re: Qantas.
It is a glaring and actionable blunder, in my opinion, and the lack of information forthcoming from the Manufacturer and Mx provider will be accomodated at Court, no doubt.

It is well to assign culpability to Oiling, and why not? The Mfg. group has said an oil fire is the cause. What of the degradation of the Oiling System that predicated the Fire? While the claim is that a stub pipe failed, no mention is made of the wear seen in this part (if the image is an actual image of the offending piece). No Oil loss is recorded in the offered data, and wear that was instigated by a possible loss of oiling is not addressed. So we continue with a lack of information, this time the victim is the Public interest, and ultimately (unimagined, one thinks) the manufacturers. This flight came within a hairbreadth of complete loss of the Engine from the wing, a ditching, or a crash. The causes were not a surprise, meaning that someone ignored a basic tenet of Aviation, one that suffers currently due to its unpopularity in the boardroom:SAFETY FIRST, and even before bonus and profit.

More than a few engineers, and non-engineers know precisely what caused the burst, it will come out, through the EASA, the FAA, or at Court.

Best wishes to you for the New Year,
bear

The hidden accusition against Lufthansa and Lufthansa Technik regarding the C check in September is no new information. It was posted several times before in the old thread to this case. As early as post nr. 240 there was a statement of a Lufthansa Technik spokesman quoted whith the content that Lufthansa Technik has no responsibility for the engines. Quantas has obviously only contracted Lufthansa Technik for the "Body" C-check only.

Under the present contract of "power by the hour" I believe even Quantas is not responsible for the status and service readiness of the engines, it´s sole RR business. There might be excemptions from this strict ruling - subject to contract details - e.g. minor service activities at the stations that are involved in A 380 operation, but thats all.
I think this whole case is much too serious to start apppointing of blame without solid facts at hand.

DERG & bearfoil

Some interesting information on the A380 and engines from the airline user's point of view (prior to QF-32), perhaps you already saw it. Look at the engine maker's views as well.

Technical issues

Happy New Year to all !!!

Turbine D

Not part of the "Tech" discussion, but an interesting interview with Captain David Evans, who was the supervising check captain.

EXCLUSIVE - Qantas QF32 flight from the cockpit | Aerospace Insight | The Royal Aeronautical Society

LH Tech / RR engine repair shop
 

DERG
that is very correct. RR and LH technik agreed upon installation of a shared repair unit that became established at Arnstadt/Thueringen. As far as I am informed about that company they do the repair on the LH TRENT 900 only , yet they may, sooner or later, also take engines from other airlines.

Wish you and all other participants of this circle a happy and prosperous New Year

Annex14

One hopes LHTek will be instrumental in developing a solution to this engine's issues.

May all here prosper and have Peace in the New Year,

bearfoil
I think it is up to Rolls Royce to develop solutions to the engine tech issues, not a repair/overhaul shop they are partnering with to service the engines.

PICTURES of the damaged wing structure
 

PICTURES of the damaged wing structure of the Qantas Airbus A380, flight
QF32, 4th November 2010, „Nancy-Bird Walton“, MSN 0014, Reg. VH-OQA

SpeedShare - Download A380-QFA-MSN014-Damage Overview.pdf

SpeedShare - Download Damages_description_wingtopskin.pdf

:ok: :ok: :ok:

TurbineD

My intent was to describe LHT as involved in the retro/repair/upgrade. Their service of the id'd engines that failed/faced failure, is critical to the explanation for the defects. From this explanation an understanding of the events can be acquired. Since non-disclosure of vulnerabilities is reported by Qantas, some apprehension is reasonable as to whether this incident will be fully understood by the Public. What is the nature of the actions taken that now create a reduced possibility of in flight Burst?

What of the year-old AD's?? What was/is being replaced other than the famous 'stub' pipe?? Further, there is the question of disclosure of meaningful concerns by the representatives of the Public?? Is the Mission of the EASA to protect Corporate proprietaries? Or is its Mission to protect the safety of the Public in Carriage??

One hopes the latter.

LHT
 

DERG´s post about that quoted LHT sentence made me dig through many reports and interviews I could find in german media. What I think has happened is, a statement of one LHT member was conveniently shaped to the editors intent. Those statements or quotations of LHT I found to the case is like quote: . . .for the time being . . .we see no reason to not operate the A 380 . .
That would make much more sense than this simply stupid sentence. One day after such a severe accident no one that uses his/her brain will make such a statement.

But to come back to more technical items.
The socalled "A mod" version of the Trent 900 is the engine installed on the first deliveries to QF and SIA
Lufthansa received its first A 380 - D-AIMA - on may, 19 2010. According information I was able to find only one engine on that plane upon delivery was a "A mod" version.
D-AIMA experienced very early into line service upon return from China an inflight shut down - 1 hour prior landing at FRA - of one engine because of quote: "irregularities in the oil system"

That engine was taken off the wing and went into that Arnstadt shop.

Next was the either FOD or birdstrike generated change of one engine on a LH - A 380 somwhere after the Qantas case had happened.

The third change of engine I know of was conducted after RR had issued that recommendation not to use any "A mod" engines until upgraded to later standard.

The forth engine switch to come is scheduled for next week Wednesday or Thursday to have that plane ready for service by Friday.

Interesting information on the side.
This engine was closely monitored since mid December. Other than directed by the EASA EAD 2010 - 0236-E LH checked it´s engine since that EAD not only every 20 cycles as requested, but instead after every ONE flight cycle !! I believe their usage of the type allows for that extra effort.
May be, that´s the difference between having the engines leased or possesing them as own property ??
Jo

Old Engineer
 

That post about bearing technologies is a wealth of information. My tech times are so far away - 1st life I usally say - that I have forgotten a lot about the specialities in that field.
Reading your information a question arose: Is it possible that aside of that AP coating - probably used in high performance jet engines - also Ceramic balls are used in such a desighn??.
From FAG information I took that any of their products used in high tech engines is custom tailored and thus probably far away from what they publish in their normal product listings.
If Ceramic balls are used, would that decrease or increase the consequences of loss of lubrication ??
Thanks in advance

deposits on IPT fragment
 

Since we look at the rear side of that IPT disk fragment the question came in my mind what kind of deposit is visible on the picture, Fig. 14, ATSB report. Starting with a shiny polished piece of craftmenship somewhere this dark greyish layer must come from.
Is it the normal agglomeration of exhaustgas that leaked into that space between the rear surface of the disk and the structure connected to or held by that demolished stator ring ?
Or, is it kind of oil cooking coming from an insidious leak somewhere at the rear end of the IPT shaft ?

Another question, how come that the supporting ring underneath the fir tree groves doesn´t show any sighn of wear when it travelled backward towards the nr. 1 nozzle guide vanes ring of the LPT ?? Or did it not at all hit that ring shifting backward, but instead desintegrated before it even got so far ??? How comes that still a ring of that demolished part is hanging inside the wrecked engine??
Is this all possible ??

Annex14
I think the bright shiny to grey color comes naturally over time. This is a hot area of the engine and the combination of temperature and air turns things grey.

The darker coloration and lighter irregular deposit on the surface close to the bore probably came from both heat (darker color) and liquid metal (lighter color) migrating out and solidifying on the disc surface.

As you point out, the rim of the disc (under the dovetail slots) looks remarkably clean. For this section of the disc, there was no apparent metal contact of the disc rim with another component.

I think the metal "ring" that you see hanging in the engine is casing material, some is totally gone, some is bent aft or forward. The in between space is where the disc, blades and nozzles exited the engine. There are two pipe rings that run circumferential around the outside of the casing at a location directly above the IPT rotor blades. I think these pipe rings provide air and are for blade clearance control, mainly at cruise altitude. You can see in the photographed area, they are mainly gone except for a piece of one still showing.

bearfoil
I agree with your statement. However, I think it to be appropriate to separate aircraft C check maintenance from significant engine inspection. I think there are limited shops you can take an A380 aircraft to have a C check done. What comes to mind at this point would be Airbus, LHTek, Singapore International Airlines and that is about it for now. So Qantas probably didn't have much choice based on their hours and operational schedule. SIA were probably busy C checking their own aircraft. LHTek was probably the only logical choice for the airframe.

The issue of Qantas Trent 9072 engine maintenance, under the Rolls Royce "Total Care Program" seems murky to me at best. I know what the program title says, but what does it mean? If RR had knowledge of technical issues discovered from any of their engine overhaul/repair stations, Germany, Singapore. UK, etc., it is up to them to provide this information to all operators in a timely fashion and in the case of Qantas, notify and take care of any technical issues on the 9072's.

In reality, we will probably never know the details. But the real point is that it should not have happened in the first place if the "checks and balances" during the engine design and review stages had been accomplished properly. There were "lessons learned" that were not learned.

In the US we have the NTSB that investigates incidents and accidents, determines the cause/causes and provides corrective action recommendations to the FAA. The FAA can either chose to accept, partially accept, or reject the NTSB recommendations. There has been a lot of "flak" flying in recent times that the FAA is too close to the airlines and manufacturers in the carrying out of their responsibility of safety to the general public, ignoring many NTSB recommendations. Don't know if the EASA has this sort of problem.

Turbine D

Thanks. I can appreciate your concern about lessons not learned. There is data about that supports your conclusions. It is technical, unknown to most folks (perhaps especially Qantas' Flight ops).

That deficiencies exist in powerplants on introduction is common knowledge. To my memory, none have ever been identified, and then ignored.

(send a PM)

Qantas A380s to return to US route, Airbus misses delivery target
The connection between the QF32 failure and high takeoff thrust on certain runways remains very mysterious if indeed there is any connection at all. Has all this delay been just about putting minds at rest and installing mod C engines? Anyway, very glad to see that things are getting back to normal.

I know that some people get a bit excited by near disasters but rememeber that "nearly" never hurt anyone. And you probably can learn as much from near disasters as from the real thing.

A good new year to Airbus, Rolls Royce, Qantas and All and sundry.

I note from the article in the travel magazine that the 'new' engines will have to be inspected after every 200 flights, then subsequently after every 100 Flights. Most unusual to see restrictions tighten after re-introduction and initial data.

The Airline person, anonymous, said the route for the 380 (LAX) is on a "wait and see" basis, so no new info there.

Airbus and Qantas are right pissed at RR, and you may want to read a more cogent and trustworthy source than a Sydney based Travel Office release.

The 900 has teething problems, the question remains, are they mitigable? The only way to know this is to examine what the workaround of the 972 truly consists of. Is the retrofit an upgrade that is thought to extend service life to advertised lengths? Or is it merely a buying of time, a compliance with existing AD's to take the heat off of reintroduction?? None of the C engines has enough TOW to give any results that can be analyzed, as of yet, no demands of 72k POT to the cycles or hours that The "A" acquired at time of the Burst.

The engineers who built and had certified the "A" are on the spot. Is it conceivable that these folk hadn't considered their lightweight newby might need upgrading?? How quickly can new internals be designed, built and tested to plug the gap in performance left wide open by the failure of the first iteration?

The bottom line is this. The certificate failed. Instead of re-certification, the Manufacturer is allowed to modify without returning to the procedures. There is no downside to grounding the 972 whilst rebuilding/replacing them, as they need to be off wing anyway. Pretty slick.

It is simply this: Qantas was offered and accepted the Thrust augmented 972 after Airbus found six tons of extra fat on the Whale. The Thrust came from a DEP, a "Chip" that opened the fuel a bit more on an engine that was DEP limited on shorter routes. The Max thrust was used carefully, in limited fashion, so essentially this engine had serious limits on it that made it a hangar Queen, a Route Limited Diva, or a test bed for how Rolls expected to gain market share. Sell engines by opening the throttle, and limiting its life. That isn't a new engine, that is a "warmed up" leftover.

I think this is quite wrong. There is nothing wrong with the type certification process. Engines meeting the relevant specifications will perform as expected albeit that a new fleet will inevitably have teething problems. In this case the engine was defective and so cannot be expected to perform in the same way as a normal engine because a defective example is not representative of type.

Following the engine failure there was obviously much more focus on teething problems to see if the known issues were linked unexpectedly to the engine failure. Once oil fire becomes a reality the pressure is on to deal conclusively with any already known imperfect oil seal even if it is not an airworthiness issue.

The type is easily capable of the thrust required for the North America flights. What has been at issue apparently has been the durability of the HP/IP support structure now apparently improved to unlimited life cycle through two successive modifications (B and C).

Yes, the type certificate process is not flawed. The engine is. How did you read my post as critical of the process?

The HP/IP structure is having problems because the engine has new demands on it, and the test process was based on insufficient information. I notice you have relented on your position of "stub pipe duff, let's move on" ??

This iteration of the 900 is expected to produce higher power at higher RPM, an invitation for gremlins to pounce. Vibration, Lightweight, and new components in a design that doesn't share enough of its predecessor's systems to qualify as a "Sister", a follow on, or a family member perhaps.

An "apparently improved" HP/IP structure?? Have you some idea what that would mean, and do you know how long that would take and that it would disable current authorization? Added weight, augmented milling and dimensions, new testing, etc. etc. Stop flailing at windmills.

Contra Rotation, higher discrepant RPM in the same box, and a "Standard" Oil System. Throw in LP vulnerabilities (via "standard" dimension, heft, and tolerances), and would you even consider that this "C" model might have better been named an "A" model of a different lineage??

An "apparently improved HP/IPstructure" Have you some idea what that would entail?? Thicker web, enhanced diaphragm dimension, and additional structure. That means a re-design, and an abandonment of the certificate. That puts the 900 effectively out of production. Over, Finito. The DEP method of sequential thrust enhancement is at risk.

firstfloor
I wonder about some things relative to the airports and the A380. At LAX, there are two parallel runways, one (25L) is 11,095 ft. X 200 ft, the other 12,091 ft. X 150 ft.
TO on the wider runway is at 250.2° and would generally be into the wind (breeze off the ocean) but at time could be downwind (Santa Ana winds from the mountains to the east of the airport.)

At JFK, the runway (13R) is 14,511 ft. X 200 Ft. TO normally would be at 133.9°.

The LAX runway is 3,416 ft. shorter than that at JFK.

Are A380s limited to 200 ft wide runways for TO & landings?

If so, perhaps a fully loaded and fueled Qantas A380 departing LAX would require maximum thrust on TO (72K) at times, especially with an east wind blowing. TOs are always to the southwest. Full fuel loading would probably be needed to assure sufficient reserves non-stop to Sydney, head winds, etc.

Any thoughts?

Turbine D
 

As you surely know, there are 2 more RWY´s at LAX, 24 L + 24 R. Both shorter than the southern pair and therefore not used, I assume. At least it wouldn´t make no sense at all to use a shorter runway if a longer one is available with these heavy departures.

RWY width of 200 ft. used to be the limit at the very early stage of introduction of A 3800, but a while later the limit was lowered to 150 ft. The much greater limiting factor to runway use are the dimensions and lay out of the attached taxiways. I know of several airports that had to widen taxiways or at least the shoulders. Also curving radii where a case of concern.

Ref. downwind take offs, I thought the general limit to that kind of operation is set at 5 kts.

Hope this one works
Aircraft Characteristics
Than select A 380 and the .pdf file with all A 380 data will be downloaded.

Good morning. Looking for some input on Shaft interlinkage via vibration. HP seems to have had the most, and to have caused secondary vibrations. This is not a tri Shaft Isolate machine, Shafts share a common airspace, and at extremely close quarters. What caused the damage to the Stub pipe? Again, the bore/align may have been off, but the wear evident in the pipe's interior bore shows excessive amounts of bore expansion, vibration??

Is vibration the source of damage to the HPIP structure?? Is it also due to insufficient strength causing flex in the diaphragm's field?What about the extra RPM's and Contra rotation?? Is there fatigue here? Are the bearings susceptible to damage and axial drift due wear from vibration and vibration instigated lack of oiling??

Bearfoil - Have we had confirmation that wear was present in the stub pipe? You seem to be pretty convinced but I haven't seen a single supporting opinion.

Was the HP/IP structure damaged prior to disc burst?

Most likely scenario remains oil fire leading to disc release and overspeed to burst.

Lawyers and machinery, a fictional account.
 

RR: It was just a stub pipe. It’s fixed, you’re good to go.
Q: Wait a minute. You see our lawyers have said we have to be sure that everything’s ok before we fly again.
RR: It is. Have a nice flight.
Q: Yeah but, the thing is, we grounded the whole fleet you see.
RR: You did what?!
Q: Well, you know, we need to know it’s safe to fly. The lawyers say we gotta know stuff.
RR: What stuff?
Q: About the A, the B and the C mods. Component life times and all that.
RR: Yeah, well, we can’t go into details but we fixed that ages ago. The fleet gets gradually upgraded as we go. Don’t worry about it. Have a nice flight!
Q: Yeah, but, you see, the lawyers are telling us, well, they’re not quite sure why we grounded the fleet, and now we need reasons for doing that and more reasons for flying again.
RR: Right. Erm. Ok, have a nice flight!
Q: Uh!
RR: I’m not sure we can help you with that one sport.
Q: Well, you know, it’s the lawyers; you gotta help us out here.
RR: Look here old fruit, we’ve got lawyers too. It’s like this. It’s a standard defence. You sue us, we shut up. Have a nice flight.
Q: Gulp! ……………. Fire up the engines!

I hesitate to get into speculation about what did happen in a specific incident about which somebody else holds all the cards of evidence knowledge and all I am providing is ignorant speculation.

But from a general sense :)

Parts not meeting design specifications are prone to early wear-out modes from even normal engine operation including temperatures and vibrations.

Fatigue itself is a wear-out mode to me. Left long enough a crack grows to a point where it opens up and squirts oil.

Failure conditions themselves often lead to cascading collateral damage. Thus a disk failure that doesn't clear the engine in a few miliseconds is sure to mess up its rotor drive shaft and bearings.

Chicken and egg questions are the challenge to the investigator and require postulations, experience, and lots of eyeballing of minute damage to confirm. Any one person is sure to get parts of the scenario wrong, so a team approach with pro and cons works best to establish a meaningful corrective action program.

lomapaseo

I have always (three years worth), held utmost respect for you and your work. From the first reading of your TWA800 Paper, I noticed you have a keen grasp of traditional approaches to questions proposed re: Failure mode/chain fail.

If you have read Shakespeare, you might discern the meaning of my internet name. Your style is, well, predictable, if I may say. You are frankly what is known in the old english as a scolde. You never fail to expound on the rather dated approach (IMO), to investigation. There is no disagreement with your post, but for one issue. Ignorance. Ignorance is a straightforward word that has a multitude of definitions. Suffice to say that I do not consider myself ignorant here, in the way you may mean.

Engine failures propagate, they may start small, and perhaps minor, but without attention they involve increasingly the other interrelated systems and components (modules). The Disc Burst did not just "happen". Neither is the Oil Fire the single Bullet theory that so many would have us believe. From the first T/O on the 380 wing, the 972 started to self destruct, as opposed to simply wear down, or out.

So did the 700 Edelweiss incident. Not due to lack of prescribed maintenance, or bad fuel, or Oil. This engine family is a Formula One engine in a Chevrolet. You will excuse the Automotive reference, but in racing, a powerplant has only to excel for a short time, its life is measured in shorter terms, and success is measured in a win, and likely retirement of the entire engine, all of it.

The TRENT is marketed as a lightweight, it is well known to weigh at least a ton less than its competitors. This is eight thousand pounds of increased useful load on a four engine a/c like the A380. Over time, that is a remarkable amount of increased profit, remarkable profit Also the brochures will tout its "Modular design", allowing for shorter turns at checks and strip. Unfortunately, Qantas was told that to retain its advantaged position due light engine weight, Thrust would need to be augmented by that ton to get an additional six tons of hitherto undiscovered weight off the deck from California to Sydney. Still with the advantage, by the mere addition of a keystroke, and not a single change needed on the Engine !!

The Fan is a new design, its shape still being fought over with a competitor. It presents new challenges to an existing design. The Fan has a "fuller" disc and drives more air, more efficiently. How completely was this Fan tested relative to new challenges? Perhaps not as completely as it should have been, with data being misunderstood or even actively ignored?? Please note the vibration reads on the failure of the IP disc on Number two. As N1 and N2 dropped, what was the IPT doing? You should know this, do you?

Finally, there is a format of incident investigation that is being used in rooms across the globe. You could google. First know this: The enemy of the Truth is consensus.

Agreement in and of itself is the enemy of discovery, so I would make reference to your mention of "teamwork". The new deal is confrontational dialogue, not in the sense of rudeness, but in the sense of exploration. It has been in use since I learned of its development at a University in California, well, a long time ago. It does not fail.

Humans think that to collaborate is good. In most things it is. It is an instinct, and like most instincts it has a place. It does not have a place in the Boardroom, or the Investigating table. Confrontation (non-physical, of course) brings to bear (!) a primal clearing of inputs and data (but not exclusively!), while one proponent can excise a nugget of new that has not been entertained because it cannot pierce the traditional paradigm of................consensus. Attacking a problem together can have unwanted results when compliance and social desires trump a good fight.

It is a long and interesting (to me, anyway), discussion. The player in the exercise who forms the wall the Truth can bounce off, is the foil, the one(s) who will fight to keep agreement at bay, and investigation at its highest expression. Please don't do anything differently. and I should not tell you this, but I enjoy greatly when you are at your most righteously snarky.

Thanks for the treasure trove of information on the A380, it will keep one busy for quite awhile studying it all.

Re: LAX - I was aware of the 2 northern runways. But, for the A380, they don't work because the taxiway (24L) is too close to the runway and must be cleared of all planes during A380 operations. The first Airbus A380 into LAX actually landed on 24R in 2007.

The airport spent $88M to widen turnoffs and build a new cross taxiway at the western end for A380s landing on 25L from the east. This may be visible from the Google map, if it is up to date.

Also, the 25L/7R runway was widened to 200 feet so that the outboard engines of the A380 didn't overhang in the grassy areas leading to potential FOD damage.

"The player in the exercise who forms the wall the Truth can bounce off, is the foil, the one(s) who will fight to keep agreement at bay, and investigation at its highest expression."

First one to say "Best Practice" gets promoted! :rolleyes:

bearfoil
This is an old article, but, it is the same Qantas A380 that is parked in Singapore awaiting repair disposition. I wonder which engine it was at LAX?

Qantas A380 grounded in Los Angeles - Travel - smh.com.au

I really must strongly disagree once again. Not formula one, not lightweight in the sense you mean. The difference is three spools, the design goal since the sixties being efficiency and compact design at the expense of greater complexity over the two spool turbofan. It has taken Rolls Royce a long time to achieve the weight advantage it presently has but it is in no sense a fragile piece of equipment. Think robust instead. The technical advantages of the three spool design grow with engine size.




Give me strength!!

Bearfoil = wrong, dead wrong and completely and totally wrong.
Truth = start by reading the ATSB preliminary report.

From experience, the runway utilisation at LAX usually has arrivals on the outer pair (24R and 25L) and departures from the inner pair (24L and 25R), so landing 24R would be not unusual.

Maybe a better question is where do the QF A380's normally park at LAX? Do they still use the Tom Bradley international terminal, and if so which stands are A380 suitable?

I understand the taxyway issues with the A380, it could be that the parking location determines both the landing runway and departure runway assignation. For example, if they use Tom Bradley northern end then 24R for landing and 24L for departure probably interferes less with other taxying traffic; conversely the southern runways for parking TB southern end.

The northern pair are, however, shorter in length, and hence may be the cause of the requirement for rated thrust usage rather than some degree of derated thrust.

digging mud ??
 

Found the attached message digging in all kind of messages probably containing something called" the light at the end of the tunnel"
Rolls-Royce Bearing Box Blamed in A380 Engine Fire

I am looking foreward to your comments

Annex14:
From the article.
And the date of this report is?

Goodness!! What's a poor ignoramus supposed to do with this?

The bearing failure, slop, flop and buzz, allowed the IP Shaft to "migrate" aft?? Isn't that what AD's are for?? So much for a duff stub pipe. Unless, unless, it was the one lubing the ball bearing thrust snubbers at IPHP. Not the one lubing the Rollers?? Tickle my arse with a feather.

Vibration, vibration, vibration. Location location location.

Question then. What of the bearing boxes in the 900?? How about in the X ?? Highly strung fuss budget? Or Gorilla meant for decades on the wing.?? You make the call.

first floor

The date is important, and more important is the nature of the Failure. When is it not allowable to organize one's thoughts around a year's worth of documents and inspections?? Jump ship because a highly suspect corporation wants to pin this disaster on a piece of tubing??? It was not Ian at the bench with a hangover. My prediction is that RR will regret having tried to mislead, and keep secrets relative to Safety. Power by the Hour is nifty, if both parties are honest, and not bent on protecting their personal hides because they've pushed the Camel over the cliff. The Camel didn't die, and he is quite pissed.

bearfoil

where's old engineer and Turbine D when they are well and truly needed.

firstfloor
 

Sorry, don´t know. Got it via this Home page : Ball Bearing, Roller Bearings & Power Transmission Distributors Manufacturers Community For SKF Timken FAG INA NSK
There it says : News and thereafter one can click on each of the brands named in the list. In that SKF list it´s report Nr. 2

just another one . . .
 

Page 31 ATSB Preliminary Report

Other party safety actions >>> Qantas

Quote:
3. Before further flight, carry out a borescope inspection of the bolted joints of the HP/IP [High Pressure/Intermediate Pressure] Support Structure area of each engine per RR NMSB G592.
Any connections to >>>540 Psi at P30 ????

Must admit, only after the probably 6th or 7 th time reading that report I struggled across this statement.

I think probably due vibration due to wear/loose tolerances, or Vibration alone, or a resonant frequency. Wonder how the Ball Thrust box was found and hung on the case post engine removal??

bearfoil - Annex14 - firstfloor
Humm, Thinking!

It would appears that we are back to the proposition: A leads to B, B leads to C and C leads to D, C = fire, D = BANG! The questions are: What are A & B, Is there A & B or just B or is it even more complex A1, A2, B1, B2, etc.

The visit of the Airbus CEO to Southeast Asia no doubt was prompted to see first hand and be briefed on the damaged aircraft in Singapore. He then probably went on to Sydney to meet with Qantas leadership to further discuss the matter as a good aircraft supplier would do with a good customer. Now if his interview only took place a week after the event, there wasn't enough time to state with certainty the actual cause of the failure, but maybe only generalities or suspicions, perhaps from technical difficulties plus modifications being made with Trent 900 engines, i.e., SIA and Lufthansa and ongoing mods at Airbus.

Here is the timeline of events as reported by the ATSB:
11/4 The "event" takes place
11/9 Flight crew interviews
11/9 Start of aircraft examination
11/11 Aircraft examination continuing, crew interviews completed.
11/12 Recovered disc section sent to UK/RR for examination.
11/13 Engine successfully removed from the aircraft.
11/17 Engine dismantling at a workshop in Singapore with the LPT module being removed to gain access to IP turbine damage area.
11/22 Parts of interest have been photographed and sent to UK/RR for further examination.
12/2 Stub pipe announcement is made with a photograph of fatigue fracture.

So I think the Airbus CEO "interview" and reporting of the same is not in the right place on the time line for any conclusive cause to have been made.

Which one? Are there two? The one of suspicion would be the one between the HPT rotor and the IPT rotor which contains the plenum chamber where the oil lines feed and drain the roller bearing box. This is also where I think the stub pipe location is.

I am having trouble believing the IP shaft could move back hardly at all without scoring the LPT shaft where it flares out going aft. There is not enough room there for this to happen without seeing the effects which are not in evidence in the photo of the removed LPT module.

Obviously, it sure would be nice to see the compressor areas of the engine to know all of this for certain.

Firstfloor - I loved you fictionalized Law vs Machine dissertation,LOL:), but probably not far from reality.