QANTAS A380 Uncontained failure.

[forget]

DERG. The FORGET poster has follwed me around last day or two and the intent is malicious.

Followed you around? Strange, other threads show the reverse. You flatter yourself, I wouldn't waste any malice on you. What I have done, when you've posted your silly opinions on subjects of which you know SFA, is to respond. You can be an amusement at times, but mostly just a bloody annoyance. Try http://www.pprune.org/tech-log/44210...lp-needed.html Full deck comes (very much!) to mind ....

I'll leave you lot to re-define engine failure. DREG, a word of advice - leave any response until it's worn off.

[barit1]

DERG:

The FORGET poster has follwed me around last day or two and the intent is malicious.

Recall when you perceived my committing (nearly) the same offense? I'd like to know what you eat for breakfast that affects you so.

All the same, best to check six...

[bearfoil]

forget has been on site for 12 years, and has thousands of posts. I have seen some incisive and thoughtful work of his, anyone can be brash, or impatient.

Fear the laid back pilot, eh?

[DERG]

Engine Life in Hours

Pax Romanis..yes Bear, thank you, AGREED
Barit1 I thought me and you were reconciled?

So are RR aerospace turbines generally sub standard compared to GE/EA et al.?

This evidence from elsewhere on this site:

"RB211-535 19,000 hours average time to first shop visit, The RB211-535E4 achieved the world record for on-wing life without removal for over 40,000 hours over nine years in operation for a 757."

RR has such a tip top reputation here in the UK in keeping with the above statement.

And generally:

"Most engine removals are for deteriorated thrust rating or EGT margin. Modern engines are getting towards 30,000 hours on wing and if I remember corectly the old Concorde Olympus were more like 300!"

Then from Turbine D we have this: Edelweiss incident

"DCA04IA002"

"Both engines were Rolls-Royce Trent 772-60/16 turbofan engines and were installed on the airplane when it was delivered new from Airbus on November 21, 2000; neither engine had been removed or overhauled since they were installed. Both engines had accumulated 15,169 hours time since new (TSN) and 2,348 cycles since new (CSN)."

Note: RR have limited the T972 to 70 cycles total life

and here from the guys in the shops

http://www.pprune.org/engineers-tech...gine-mtbf.html

Moreover these airliners are not dropping out of the skies, I see them often on the 6 500 mile hike from central Europe to the W Coast of N America spinning their silken contrails as they battle the western winds. This has been going on for 45 years or more beginning with the B707, never a deviation from the steady progress across the sky

Despite the fact that GE appears to have the advantage of newer technology and access to better academics, RR are not done yet.

[Turbine D]

Engine Life - Hours verses Cycles

DERG

Don't get too hung up over hours representing engine life. The best measure of aircraft engine life performance is cycles, that is, how many cycles are accumulated on wing before the engine requires removal and overhaul. It would be expected that engines on an extended range aircraft flying 10-14 hours routes would accumulate hours rapidly but cycles less so and would stay on wing longer compared to an aircraft that does short flights of 2 hours or less, but with 6-8 multiple flights per day.

Hours are easily understandable by the average person and quite a few advertisements cite long hours accumulated (bragging rights) before engines come off wing.

Even TBO (time between overhaul) cycles vary between operators using exactly the same aircraft and engines. It depends on general operating conditions, high altitude airports, or hot, dry, dusty conditions (desert airports), exposure to sea salts (corrosion), e.g., airports near the sea.

The exception to this would be gas turbines used in electrical power generation or natural gas pumping. There, hours, really defined as years, are the important factor. There are no cycles to speak of. Turn it on, take it up to operating speed and expect it to run 20 years with little attention if the designs are good.

[bearfoil]

Indeed. had a chance to work at a power station here in Cali. JT8Ds. Fire and forget. Simple designs, robust build, and constant monitoring. The secret was to scrub intake air to nil fod. The cleaners were changed often, and the fuel was inspected daily. In its niche, the Turbine is a brilliant workhorse.

Service Life in this incident is pretty much a red herring, imo.

Safety is the salient issue, not economy. The first picture of the 972 off wing showed the absence of the EEC. Anybody know where that little beauty ended up?? For it is here that the failure is found. Any engine will blow up when run under heavy load with compromised condition. The Kill Switch killed the kit.

[DERG]

Industrial Turbines

There are 28 companies who make industrial turbines. I think it is interesting to see how RR sits in this application.

In terms of mechanical drive generators only one company makes a model that produces more power than RR. That of course is GE.

"The Kill Switch killed the kit" Yeah...

Perhaps we are at some cathartric point in the course of technology. At RR we have a bunch of people who cling on to the 1950s because they just can't find the right road to take. They do their best to make it happen and suddenly events take them right back to the days of the Comet.

The young engineers are used to making the virtual world real. Then suddenly the ghost of the past wakes up and says "We tried that in 1949"
The Hughes corporation comes to mind.

Anyways time for some entertainment....to date THE BEST proven load carrier on the planet...
YouTube - The Steve Miller Band - Jet Airliner Boeing 747 Take offs (Watch in HD)

[radken]

I rediscovered the link below which was contained in the previous thread from the PPrune rumor mill before the topic was moved to the Tech area. There are likely many now participating in this present thread who haven’t read this very interesting and revealing interview of a senior ck pilot who was onboard QF32. It’s not often “we the public” get to read or hear in such candid fashion the particulars of such a momentous event - litigiousness being what it is at least in the US.

For instance, I had forgotten (see previous post) there is an engine fuel shut-off feature associated with the cockpit “fire” buttons.... I don't know if that also includes the pylon valve but would presume so. The pilots were surprised to discover, however, that #1 was literally OOC. In line mx., when these systems are “tested” in hangar or on the gate there are no engines running, so who’d know if a particular s/o redundancy would actually be functioning or not? Bottles would be disconnected and what could ECAM tell you that you could believe? There was such severe damage out there in that wing that possibly no amount of redundancy engineering would have saved the day anyway.

The whole thing will probably be made into a movie soon.

http://www.aerosocietychannel.com/aerospace-insight/2010/12/exclusive-qantas-qf32-flight-from-the-cockpit/[/URL]

If the link doesn't work you can find it archived (I believe) at aero's site...

[DERG]

Living in Hope

This failure is something I am hoping the ATSB will address. If the safety authorities are to be respected they need to enforce something as basic as this.

[NigelOnDraft]

Deduction 11
The failure to be able to shut down the #1 engine on the stricken Qantas A388 was unforseen.

..a big lesson that i am sure has been properly thought over.I do not know the results but from the discassion over here it is not a simple problem.

11. A lesson learned on the A-340 that hit the wall on the ground in which they couldn't shut off the engine for 5 hours was thought to be a not repeatable incident.

It’s quite discomforting and significant to know, without any doubt whatsoever, that the QF32 crew would have had absolutely no control (except fire bottles- if they would have worked) over a fuel fed engine/pylon fire at #1 at any point after the #2 burst....The truth is, though (I believe), no cmcl jets have redundancy in this area.

..in what should be an “infallible” engine/pylon fuel cut-off system should be addressed by Airbus (Boeing, etc.) ASAP. Redundancy in hydraulics, electrics, tank plumbing? Why not in fuel shut-off, too?

I think some are getting too hung up on this. There is "redundancy" in the engine shut off, AFIAK there are 2 physically separated electrical circuits to do this, and in this event, both got cut.

To create "a tragedy", seems therefore to require 4 very unlikely specific events:

1. A failure that is uncontained (as here, unusual and has to be addressed)
2. >1 fragment that causes damage elsewhere (I saw somewhere design assumes 1 fragment)
3. These 2 (or more) fragments fortuitously cutting the separate redundant paths of an important system
4. That system's failure then leading to a signifcantly increased safety problem.

If you over-concentrate on "shutting" an engine down, you end up with engines shutting themselves down of no accord - a far greater, IMHO, safety issue
We had 3 of 4 "unlikely" events, P of the 4th is small?

Or look at it another way, if you over-emphasise the need to shut engines down, then maybe Airbus could have designed the shut off curcuits to "self monitor", and if both circuits were cut, to shut down the engine. Sound a good design? Maybe, but in this case it would have given them a double engine failure

A manual shut off valve? (in the pylon?) - OK, maybe a good idea, but really enhancing flight safety? In both the quoted cases, once an engineer is in place to operate it, everybody was, or could be off, and well clear anyway.

I suspect the ATSB will look at it, but I disagree they will place strong recommendations on addressing it. As an airline pilot, I am wary of too many "safety systems" being too cleaver - they usually cause more problems than they solve. I am "nervous" of the software in the Trent that can "shut the engine down" without warning / pilot control.

[bearfoil]

QF32 had a major problem with its monitoring and fuel control vv shutdown in the first place. Problem solved (?) with new software. #2 should have shutdown well before Burst. That was danger enough to have brought down this flight. Two cold engines on one side is not a good thing. I am with you, losing #1 due auto shutdown would have been not good. The Burst caused the very real worry of loss of this flight. So to answer the Burst with more "Automatic Shutdown" seems contra sensible. The EEC and monitoring programs were at fault. Looked at from a failure trail pov, the Burst was secondary to cocked up controls at the outset, No?? There is a fair amount of attention being paid the Data Entry Plug and its interface with the two channels of the EEC I'd wager.

[DERG]

"I suspect the ATSB will look at it, but I disagree they will place strong recommendations on addressing it. As an airline pilot, I am wary of too many "safety systems" being too cleaver - they usually cause more problems than they solve. I am "nervous" of the software in the Trent that can "shut the engine down" without warning / pilot control."

If the ATSB cannot mandate this VITAL shutdown device
they are superflous to the industry..

All it needs is an external valve that rescuers can access.*

*NOTE: Colleagues on this thead have correctly pointed out this would be impossible due to the danger of access a running jet engine.. OK lets call it a MASTER OFF switch. It is ridiculous that telemetry can "read" these engines 12k miles away yet we cannot turn 'em off.

[bearfoil]

A valve that a groundperson could reach would be (have to be?) positioned within reach on the engine or pylon. By the time QF32 was on the ground, danger of in flight fire was by definition not possible. The fuel leak was at the forward spar near the Fuselage, and interior the wing. At best, #1 could be stopped with such a provision, but we know through unfortunate circumstance (TooLoose) that run on is relatively safe. Fuel fire was avoided by QF32 by mere chance, mid air, one of many fortunate blessings. One could even argue that because #1 ran on, fuel was removed from the penetration area of the wing, perhaps forestalling a mid air fire. IMO.

[barit1]

If you think QF32 #1 engine continued running is a problem, consider this:

Fighter aircraft with inlets behind the cockpit, belly landing, disabled pilot unable to "pull the plug" on operating engine. How do you safely rescue the pilot?

[NigelOnDraft]

QF32 had a major problem with its monitoring and fuel control vv shutdown in the first place. Problem solved (?) with new software. #2 should have shutdown well before Burst. That was danger enough to have brought down this flight.

I am with you, losing #1 due auto shutdown would have been not good

I have not followed this thread to the detail of you / some others.

However, what you/others seem to be saying here/previously is that there is software in the Trent that can shut the engine down automatically. Such software failed in this case to act, and was rapidly modified post event. That such software exists was "news" to me, and I would be nervous unless it was 100% bullet proof. It should not be there to "protect" the engine, but solely to prevent "in extremis" failures that will result in serious uncontainned failures. Else there is a risk it mirrors:

losing #1 due auto shutdown would have been not good

- the day we get engines auto-shutting down unnecessarily is a bad day... automation gone too far.

All it needs is an external valve that rescuers can access.

Complete and utter waste of time, safety-wise. If the recuers can reach the engine, they will have got the pax out first. Little safety benefit, might save a bit of fuel / noise and get aircraft moved earlier, maybe save an airframe. But not people.

If the ATSB cannot mandate this VITAL shutdown device they are superflous to the industry...

Disagree 100%, suspect we'll leave it at that

[Turbine D]

In general, I agree with you, auto shutdown of an engine by a computer is not a good thing.

Focusing only on the #2 engine (the one that failed), it was operating in auto-thrust mode. The EEC apparently detected a un-commanded reduction in N2% and immediately called for increased fuel flow thereby increasing the N3% eventually to 98% before reducing fuel flow. By then, it was too late to prevent the eventual disintegration of the IPT disc due to overspeed.

IMO, I suspect the EEC was reprogrammed to view reduced N2% and the start of increased N3% as a problem and the need to reduce fuel flow, not increase it. This may have saved the day, possibly. However, reducing fuel flow is not an auto shutdown, the decision to shutdown the engine is and should be the flight crew's decision.

[lomapaseo]

If the ATSB cannot mandate this VITAL shutdown device
they are superflous to the industry

The ATSB job is to investigate set forth the causal factors and make recommendations.

They are not regulators nor should they mandate changes that may be impractical.

Once the full report is released I'm sure that knowledgeable safety experts will support practical changes.

This thread is suitable for discussion of facts and points of interest.

Is there anything newly released out there:?

[Annex14]

rollercoaster

Reading myself after several days of absence through the meanwhile placed 75 posts, I got a bit the feeling of a rollercoaster. There are - as usual one is tempted to say - many well founded posts with useful information. But there were - once again - amusing attempts of a peeing competition recognizable, who and where and on which side of the pond the best engines are made. Finally I reconned also some useless baloneys. Thought we are a rather professional circle.

That all reminded me to Murphys law, not the short version but the one Robert Murphy, Edīs son has passed on:

"If there's more than one way to do a job, and one of those ways will result in disaster, then somebody will do it that way."

I believe excactly that killed engine #2 on QF 32.

I also think that it is the centre point the discussion in this thread has disclosed. I believe that those possible root causes or contributing causes identified can be listed this way.
- vibration of unexpected strength and probably unknown origin
- problems with the oil system
- probably problems with the bearings
- known and probably also in this model existing problems with oil vent tubes
- unexpected problems with stiffness or strength of the support structure of
bearing chambers

One word to the idea of an external switch somewhere close to the engine or pylon. I would like to meet that hero that is willing to get so close to a running engine of that size to activate that switch.
Another word: I emphatically agree in the reluctancy of NoD to rely on a "fully automated robot". In my opinion any computer or automatic device can be only as good as the brain that has desighned it (s.a. Murphys Law).
Therefore any artificial intelligence needs a human brain controlling it.

[Suzeman]

Just been advised that A380 VH-OQD on QF32 LHR - SIN has diverted into DXB. Not the same a/c as that involved at SIN, but obviously some problem that made the crew decide on this precautionary diversion.

[Annex14]

U415967

Well, you call it unsubstantiated rubbish, many of the participants in this thread - as the top line says - call it Rumors !!
Could be that all these many entries - the collection of thread 1 and thread 2 approaches about 2500 !! - are apain in RRīs neck. As usual they would have preferred to run this in the "noble" and silent way they usually handle these cases. Okay with me and many others, but to think independant fortunately has not yet become forbidden in this free world.
So as you seem to have a deeper insider knowledge to the case, feel free to "teach" those "unknowing".
And by the way, a bit more personal information than just "Seattle" would be of great help to balance the base of knowledge.