Airline Explosion in Indonesia

[allardjd 1,853]

Pieces found; reported to be Qantas Airbus; reports it was circling and dumping fuel. No confirmatinon yet at the time of this article.

 

http://www.foxnews.com/world/2010/11/03/plane-crash-reported-western-indonesia/

 

EDIT: Article has been updated - Qantas denies crash; says an AC lost an engine (perhaps literally) and is proceeding to Singapore to make an emergency/precautionary landing; Indonesians still reporting some large debris found.

 

EDIT: Yet more changes to the original article; Qantas now saying "...engine shut down..." and "...aircraft can fly safely on three engines...", making it an A340 or larger if it's really an Airbus; Singapore to Sydney flight.

 

EDIT: Now reported to have landed safely in Singapore.

JDA

[stu7708 244]

And according to MSN it was a A380 with Rolls-Royce engines.

Quantas has decided to cancel all A380 flights until they have found out what caused the enginge failure. MSN also reported fire under the fuselage after landing.

More info here, but I can't wouch for the reliability of that source with regards to flight related stuff.. no mention of fire there, but they do claim that the firefighters sprayed the failing enginge with water. Prehaps just as a precaution.

EDIT: I found a video of the plane after landing too.. looks like a similar event as the Quantas 747 that had to return to San Fransisco a couple of months ago..

Video can be found here. Sorry for the swedish commentary.

[mutley 4,498]

There must have been one helluva bang

[stu7708 244]

Man, those enginges are massive.. sure I knew the A380 is huge, but most of the shots I've seen has only included the plane itself, and nothing else to use as a reference for how big it really is. With the ground staff in the foreground it suddenly dawned on me just how huge that thing is.....

And yes, it must have been one one loud bang when that blew...

[needles 1,013]

All souls on board were OK I take it?

That being the case, well done to the flight crew for getting her down safely.

It does look extraordinary though eh?

One expensive engine kaput!

[hurricanemk1c 195]

In referring to the title, not explosion, more va, va, boom!

This can't help Rolls. The Trent 1000 for the 787 failed a couple of months back, the engine also not performing as expected. Now this

[allardjd 1,853]

Latest word is that it was an uncontained engine failure, probably a wheel coming apart. There is also information that control wiring to the outboard engine on same wing was affected and it could not be shut down.

 

If the engines are subject to wheel failures there's some work to be done hardening, re-routing or adding redundancy to systems that are in the affected zone.

 

John

[hurricanemk1c 195]

Also heard Singapore have grounded their aircraft (same engines) and the FAA are thinking of a flying ban for all A380-841's (Rolls again)

[allardjd 1,853]

Lufthansa and Singapore have each had an engine problem too, all on R-R engines. The GE/P&W engines (less than half the fleet of operating A380s) have SO FAR been unaffected.

 

Engine failures, while infrequent, do happen from time to time. Uncontained engine failures which affect other aircraft components, systems and structures, as this one did, are infinitely more serious and cannot be taken lightly.

 

If this was in fact a wheel failure, that's just not supposed to happen and they will have to figure out why and how to prevent it. As opposed to blade failures, a wheel coming undone unleashes a few high-mass, high-energy pieces that can be very, very destructive and very difficult to "armor" against because the projectile has so much kinetic energy. F=MV^2 applies and M is large. Stopping a 2-oz. blade is small potatoes - stopping a third of a 200 lb. wheel is quite another matter. The best medicine is prevention in these things and that may well mean going back to the drawing board on the engines. Whatever the fix is, it won't be cheap and will most likely have to be backfit to the other engines already in service.

 

Finding the pieces of the wheel (if that's what happened) so that the fracture surfaces can be examined may be critical - and extremely difficult if they were ejected from the nacelle, which appears to have happened.

 

Best case is that it will be a latent metallurgical flaw of some kind that can be inspected for relatively easily, both in the supply chain and in the in-service engines. It will mean that something slipped by inspection in the manufacture and assembly of this particular engine, but that's fairly easy to deal with in the manufacturing process for future engines. Tighening up the inspection procedures is infinitely preferable to having to re-design, re-test and possibly re-certify a new engine design.

 

Worst case is a design that is flawed or is inherently susceptible to wheel cracks. That would, at very least, require designing and building new parts and unstacking the rotors to introduce the new ones. Radial cracks in wheel hubs have plagued turbines since turbines were invented. The guy who can do the most about them is the designer. If a design is susceptible to them and is unleashed on the operators and maintainers, it's a difficult thing to detect, monitor, predict or generally guard against.

 

Look for the A380s to go back into service relatively quickly, perhaps with some engine inspections first. I would not be surprised to see some new operating limits imposed, at least until this particular failure is better understood.

 

John

[hurricanemk1c 195]

Singapore have allowed the A380's to fly again

[VH-MAL 0]

I have been following this incident closely naturally enough, and have seen lots of press releases etc regarding it.

It appears that a part of the number 2 engine broke apart, and most of the fragments ended up on the ground, the biggest being part of the cowling about six feet (measurements for you John) in length. Unfortunately for the investigators, the locals picked up the pieces and brought them to a central location where they have been collected by officials.

It also appears that a fragment did penetrate the wing, with a small gash appearing at the top of the wing just inboard of the number 2 wing root, so I guess they were lucky that it did not seem to cause any major problem.

There has been no mention of any wheel damage, and from the coverage I saw, all wheels looked perfectly round and were all in use when the A380 eventually touched down after dumping heaps of fuel into the sea off Singapore.

And would you believe, within 24 hours of that incident, a Qantas B747 had to return to Singapore not long after takeoff after it had an engine failure - just a few sparks this time! And some of the people on that flight had been on the ill-fated A380 :001_th_smiles48:

Malcolm

[allardjd 1,853]

Mal,

 

My apologies - I'm guilty of poor communication, which I hate when others do it.

 

My references to a wheel failure is to a turbine wheel. The rotating blades are carried in the periphery of relatively massive "wheels" that are stacked up on the shafts. There are various means of retaining the wheels on the shafts, e.g. keyways or shrunk on.

 

The problem is that most of those methods either heavily stress the hub section (pressing or shrinking on) or create "stress risers" where mechanical stress is concentrated (keyways). Each wheel is subject to tremendous centrifugal force while the turbine is turning. If a crack develops in the hub section and propogates far enough outboard from the bore, the wheel will "burst", i.e. fly apart, usually in three segments of roughly 120 degrees of arc.

 

Unlike blades coming off, which is much more common, when a wheel bursts, because of its large mass, the centrifugal force is usually sufficient to rupture the engine casing and nacelle. That can easily lead to collateral damage to electrical circuits, fuel plumbing, bleed air ducts, hydraulic lines and all sorts of other things that one would wish to remain intact. Wheel failures are just not supposed to happen - there are too many other things that can be affected and the aircrew may well be faced with much more than just the loss of an engine.

 

See photo below - that should give you some idea how massive the wheels are. They are typically a steel forging and may weigh a couple of hundred pounds. Judging from the photos of the Qantas failed engine, it looked to me as if the main failure was further back, in the hot section. This photo is of a high-pressure compressor section - forward of the combustion chambers. It sees a lot of heat in operation, but much less than the hot section, which is operating directly in the exhaust gas stream from the combustion chambers. That extreme heat reduces the strength of the steel, so the wheels must be designed to be strong enough to retain their integrety even in those high temperatures.

 

 

 

Sorry for the confusion. When I said "wheel" I wasn't thinking of landing gear.

 

John

[ddavid 149]

Wheels within wheels, eh, John?!? And thanks for keeping us informed on this - RR are close to us Brits' hearts...

Cheers - Dai.

[hurricanemk1c 195]

Not only some of the passengers on QF6 (the 747) were from the '380, but the crew from the BigBus were on-board aswell!

[allardjd 1,853]

Missing turbine part key to A380 emergency probe

 

http://my.earthlink.net/article/top?guid=20101106/94498d46-6759-4c64-ae4b-ae7d704c4457

 

More news. This is major - not a run-of-the-mill, contained engine failure. If it were only that, the A380s would be flying and the R-R share price would be unaffected. This event and its potential implications for Rolls-Royce are much, much more serious. From the article...

 

Investigators of last week's engine explosion on a Qantas superjumbo focused their search Sunday on a missing piece of turbine from the Rolls-Royce engine, and the airline said it hoped to have its grounded fleet of A380s back in service within days.

 

The Australian Transport Safety Bureau, which is leading an international investigation into the blowout on the world's newest and largest airliner, appealed for help from residents of Indonesia's Batam island to find the missing chunk of a turbine disc.

 

"The recovery of that disk could be crucial to a full understanding of the nature of the engine failure, and may have implications for the prevention of future similar occurrences," the bureau said in a statement.

 

As the hunt for clues went on, the bureau said that one piece of the shattered engine that had been found on Batam was being sent to Britain for examination by Rolls-Royce engineers, under the supervision of bureau investigators.

 

There are several reasons why a disc might fail, but they usually involve the metal used to make the disc or the manufacturing method, Goglia said. He cautioned that he was looking at one photo, which was not enough information to make a definitive judgment.

 

From the above, it's now looking certain that it WAS a wheel (disk) failure and that they have recovered at least one piece of it.

 

This doesn't bode well for R-R, however it is to be hoped that this was a single flawed part (incorrect material, poor heat-treating, inaccurate machining, incorrect assembly, or a flaw, crack, inclusion, lap, void or other metallurgical anomaly) that somehow escaped being caught by the Quality Control processes. In highly stressed parts, even a scratch, or a burr at a critical location can be enough to concentrate the stresses and give a crack a place to begin.

 

This is still a major faux pas for R-R, but if it can be proven to be a one-off problem rather than a design issue, the recovery is infinitely easier.

 

On another forum I'm following, there is criticism of the financial analysts who are taking a cautious position and whose analysis caused R-R's stock prices to take a big hit. While it may be premature, there is reason to believe that this MAY turn out to be devastating for R-R if the wheel failure, which should be a nearly impossible event in a properly designed, built and maintained engine, turns out to be the result of a design issue that affects the whole Trent 900 line. If that turns out to be the case, those who sold their R-R shares on Friday will be very happy they did.

 

John

[ddavid 149]

You know, John, I find it very difficult to balance, on the one hand, the impact of statements made by the financial analysts who are taking a cautious position and whose analysis caused R-R's stock prices to take a big hit., and on the other, what, from an engineering point of view, is a nearly impossible event in a properly designed, built and maintained engine.

Given that the design of the Trent 900 line hasn't been subject to the 'normal' pressure, by the company's accountants, to achieve the required specification at minimal cost, this smacks, to me anyway, of interested parties 'playing' with the value of shares. As you point out, those who sold their R-R shares on Friday will be very happy they did, particularly if financial return was their original objective in buying their share-holding in the first place.

Maybe I'm just a biased, old cynic, but it's a skewed world, where companies are valued on their 'market image' rather than their products.

Nuff said!

Cheers - Dai. :trying-to-remain-cool:

[allardjd 1,853]

I'm not a R-R basher. They are a fine, old, respected company with an almost unmatched aviation heritage and their name is often equated with the very finest. They do good work, produce good products and are in the upper tier of reputable companies world-wide. Their reputation and their work are amongst the best.

 

What I can't get by are the facts...

 

1) A Trent 900 failed catastrophically in flight in a way that design and certification criteria for both engine and aircraft cannot permit. For the A380 to be certified, either the engines must be virtually immune to that kind of failure or the aircraft immune to it's effects, or both.

 

2) An un-contained engine failure of that kind (massive, high energy ejecta) has a high potential for affecting systems, structures and components other than the failed engine itself. This is a real safety issue that goes well beyond the effects of simply losing one engine in a 4-engine aircraft.

 

3) The engine is used in the largest airliner in the world, usually carrying about 600 people.

 

4) The Trent 900 sells for, as far as I know, about $13 million per copy (that may be GBP or Euros, which would make the value greater - not sure) and R-R expects/expected high-volume sales of it in support of the A380 program.

 

5) There exists an alternative engine that A380 customers can opt for if this event leaves them uncomfortable with the operational safety of the Trent 900.

 

Those are facts - beyond disputing.

 

The remaining, supremely important, unknown fact is the cause of the failure. More precisely, is it a one-off or a design issue? If the latter, then R-R will be faced with a catastrophe. Customers will run away and the costs of re-design, re-tooling the manufacturing and possibly re-certifying the new design will be very high. Coupled with lost sales, the costs would be astronomical.

 

Do not equate this failure with a garden-variety in-flight jet engine failure. This event is not being blown out of proportion - its on a par with the Sioux City crash, where a shaft failure released an engine fan that took out triple-redundant hydraulic systems and left a 3-engine aircraft with nothing but throttles on the remaining two engines for control. This was that kind of failure, but thankfully didn't cause that kind of collateral damage. It did fail 1 of 2 hydraulic systems and caused complete loss of control of the other engine on the same wing. It would not respond to the throttles and could not be shut down. That's serious stuff - all the more so when there are 500 people in the back.

 

In the Sioux City crash, the result was that the shaft itself had a metallurgical flaw - it was a quality control issue, not a design issue.

 

The industry and the financial community are not over-reacting to this. It really IS that serious.

 

As I've stated before, it is to be hoped that this can be proven to be a one-time case of something slipping through the quality control that should not have. That's bad enough, but easily fixed.

 

In my opinion, the people on that airplane are lucky to be alive. A piece of turbine wheel that probably weighed around a hundred pounds tore completely through the leading edge of the wing, leaving an exit wound that appears to be at least a foot across. The aircraft and the people survived this time, but it was a much smaller lighter object that spectacularly killed a Concorde - arguably killed all the Concordes.

 

Engines must not fail in that manner - ever. Design, inspection, maintenance and operational precautions must make that so statistically improbable as to be essentially impossible.

[hurricanemk1c 195]

Just to add to RR's problems, P&W are filling a lwasuit against them for 'using a patented style of fanblade' in the Trent's 900 and 1000. If sucessful, Trent 1000 supplies will stop to Boeing and the 787.

The topic is on Airliners.net, can't miss it

[VH-MAL 0]

Mal,

My apologies - I'm guilty of poor communication, which I hate when others do it.

Sorry for the confusion. When I said "wheel" I wasn't thinking of landing gear.

John

No apology needed John, I realised what you were talking about once I saw the partial turbine wheel recovered so far. They are looking for the rest of that wheel for obvious reasons as it may give them a clue as to the cause of the fracture.

And I've just heard on the news that Qantas are more closely inspecting their A380 RR engines following reports that they have found oil in the engines in places it shouldn't be. So their fleet (of A380s) remain grounded for the moment.

Malcolm

[allardjd 1,853]

I wonder if Singapore Air Lines wasn't a little hasty re-launching theirs.

 

John

[allardjd 1,853]

Photo of the recovered wheel fragment here - about one third, as expected...

 

John

 

http://www.flightglobal.com/articles/2010/11/07/349416/picture-australian-safety-board-missing-qantas-a380-engine-disk-evidence.html

[IcedUpPitotTube 0]

Qantas continues the grounding of their A380s due to a discovered oil leak in engines in 3 of the 380s. It is now clear that the problem is specific to the Trent 900 engine. Rolls-Royce is (still) trying to find the problem behind the explosion and the oil leaks. Qantas shares fell to as low as 4.2 percent, and RR shares fell to as low as 10 percent. The airline is forced to lease aircraft from British Airways to compensate for the grounded A380s.

New York Times Article

[allardjd 1,853]

Singapore Airlines pulls 3 A380s due to engines

 

http://my.earthlink.net/article/top?guid=20101110/a6c8f043-2987-44a4-ad9a-7e707bdf0ba1

 

Singapore has grounded 3 of its 11 A380s with oil leaks.

- - - - - - - - - - - - -

"Singapore Airlines grounded its entire fleet of 11 A380s following last Thursday's engine explosion on Qantas, but after initial checks, returned them to service Friday. However, on Wednesday, based on fresh analysis of the tests, Singapore took three of its A380s out of service again, because of oil stain results...

 

Singapore's eight other A380s, also flying with Trent 900 engines, remain in service...

 

Singapore Airlines said it does not know whether the oil stains found in its engines have any connection to the engine oil leaks found on Qantas, but was temporarily pulling the planes from service as a precaution. The planes, in Melbourne, Sydney and London, will be flown to Singapore without passengers, where they'll be fitted with new engines...

 

Lufthansa spokesman Thomas Jachnow said the airline was aware of the Singapore problem, but its maintenance crews had not found any oil leaks in their Trent 900 engines..."

- - - - - - - - - - - - -

John

[allardjd 1,853]

Oil fire may have caused A380 turbine problem

 

http://my.earthlink.net/article/top?guid=20101110/891e8720-53e2-47db-aefb-a7916493387b

 

I'm a bit skeptical of this one. It's hard to postulate a series of events beginning with an engine oil fire that would have caused an otherwise healthy turbine wheel to come apart.

 

For the engine to shed a fragmented turbine wheel as this one clearly did, the only two credible scenarios would seem to be...

1) a pre-existing crack, flaw or weakness (i.e. wrong material or wrong heat treating) in the wheel hub area

2) turbine overspeed.

 

If it were an overspeed, I would think the FDR would have that captured beyond a shadow of a doubt.

 

I guess it's remotely possible that a fire might have affected the control circuits and caused the FADEC to lose speed control of the engine, but that's a stretch.

 

Most postulated faults have the FADEC software leave the engine power as-is. We saw that in the other engine on the same wing, which could not be throttled or shut down. They had to gag that engine with a fire hose after landing to stop it, an example of the controls leaving the engine power in an as-is configuration if there's a serious fault.

 

In the case of the #1 engine, that fault was probably the wheel debris from #2 engine severing control channels, either wiring, pneumatics or hydraulics (I don't know the mechanics of the engine controls but suspect it's mainly electric).

 

It will all come out in the wash and we'll see what the experts have to say, but it's very hard to connect the dots from an oil fire to a burst wheel. The statements in this article just don't ring true to me.

 

John

[Aidan 1]

I like Qantas