Qantas ground A-380's

Wow, from those pics it looks like it shot peices from the bottom of the wing right through the top.

 

At least the A380 has four of those mills. While the Trents used on the A330 and 777 are different versions of the engine, with only two of them on the airplane, I wonder what users of those aircraft are thinking right now?

 

Interesting, It looks like something in the turbine section came apart. The hole in the wing looks like where a turbine blade went throough. Lucky it didnt go through the cabin.

 

I suppose it depends on how many millions of hours they have on them and what the failure rate is. Im sure they've had issues but this is the first ive heard of one. Sometimes engines just fail, doesnt necessarily mean a design flaw, time will tell.

 

Or ignite some fuel or cut a hydraulic line!!

 

Passenger films it!!

http://www.guardian.co.uk/business/video/2010/nov/04/qantas-a380-engine-failure-video

 

It doesn't look like it was a disk burst, if a disk had burst the damage would have been a lot more significant, (like big sections of the engine cut in half), but there were some decent sized parts coming out so it is likely that there was a failure of multiple blades. That can happen if an attachment fails on a disk and it will "liberate" multiple blades.

These engines haven't been in service for that long so this is clearly a premature failure. These things can happen if the material for the disk isn't up to snuff, of if somebody doesn't manufacture the part correctly (leave out a peening operation or leaves a scratch or a stress riser in the part). It's really hard to figure out what happened unless you have the part that broke in the first place. If you have the part that caused the failure (and it wasn't mashed up in process of the failure) you can usually figure out what caused the problem and address it. If this was the fleet leading engine they are going to want to look at the rest of the engines on the plane for signs of cracking or impending failure.

Engine companies guarantee performance and there is also likely some language in the contract that says if an airworthiness issue comes up with your engine you will pay for aircraft down time. If Quantas has a clause like that in their contract and they want to stick it to Rolls that could be a be huge amounts of money that RR would have to pay in this case.

 

Engines don't just fail. If there is a material flaw or somebody goofed in the design process and put too much stress into the part, things will break. Or if there is some vibration that is occurring that wasn't discovered in the testing program, then things break. But modern gas turbines are designed with extensive analysis and the fact that they typically go 20,000 hours of operation before being taken out of service for poor performance is a testament to that design and analysis. A failure like this is very rare, and for it to happen in a relatively new engine is even more cause for concern.

I did failure analysis for a while for a big engine company, and field failures were pretty rare. When one happened, it got our attention immediately.

 

Thats what i meant when i said sometimes engines just fail. Fatigue, poor maintenance, bad parts, etc etc.............

 

So what at the chances that the thing ate a bird or some piece of FOD and this is the result?

 

Not too likely. The parts that were "liberated" look like they came from the hot section of the engine. If you had damage from an FOD event it would be further forward in the engine and parts aren't likey to come out of the cases since they are pretty light. In big fan engines a lot of the FOD goes out of the fan duct and not down the core. If it goes down the core it usually wipes out the back stages of the compressor before it can damage the hot section stages.

 

It seems Quantas have more problems than just with the Airbus A380...

BBC News - Second Qantas jet in engine scare

Qantas 747 Lands in Singapore After Engine Trouble - FoxNews.com

I wonder what type of engine was being used on this 747. If it wasn't a Rolls-Royce Trent 900 engine, then it would seem that either there's some sort of maintenance issue going on here at Quantas or some kind of environmental phenomenon causing the failures.

Given that these two engine problems occurred within such a short space of time of each other, I cannot accept that they are disparate problems and must be somehow related.

All the best,
Andrew.

 

Spooky thing here.

Today I took a pic of a 747-400 passing over my house at 2:54pm.

I checked up on the Quantas flights and remembered that a BA flight had once lost all 4 engines in the same area, or atleast not far from there (Indonesia).

While I read the story it mentioned another plane with a similar incident. A KLM flight. #867 back in 1989.

Now it was also a 747-400, and I could swear that the plane I took a pic of earlier today was also a KLM plane.

Anyway, for the fun of it I tried to track flight 867. It left Amsterdam Schiphol at 2pm today on the way to Osaka, Japan. I thought the quickest way would be to fly over the Northern Hemisphere. Sure enough. KLM Flight 867 passed over my house today and I took a pic of it
It can't be any other plane.
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So it was another Rolls that decided to stop working...I'll stick to GE from now on.

 

This flight was probably full of yesterday's A380 passengers.

I guess most of them are now checking alternative ways to reach their destination!
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The only thing that should not be contained when an engine comes apart is the fan section, where the parts are just too big and have too much inertia to contain. Something is amiss when we have uncontained failures of the act sections of an airliner engine. Either that or we now have engines so big we have reached to limits on containment technology, which I find hard to believe. Sounds like maybe a little too much attention was paid to weight savings and not enough to safety. An engine failure on an A380 should not be a big deal, even at take-off. Like someone said, I would be concerned if running those engines on an ETOPS aircraft.

One reason I do not sit in the seats next to the fan section.

Taz
Terry Phillips

 

That one was attributed to volcanic ash, which apparently was not the case with the current problem.

 

Yeah both the KLM and BA were because of volcanic ash.

Wha are the chances of particles in the air after the recent Indonesian volcano eruption? It's not THAT far from where the two planes had to turn around.

 

Fan blades are designed to be contained. There is a failure criteria for fan containment, and you have to basically contain the blades, which was more energy than the containment system could handle. It's a lot easier to contain a composite fan blade than a titanium one since they are a lot lighter and they tend to break up when they hit the case. Containment tests are part of every cert program. Most fan containment systems consist of kevlar cloth wound around the fan case that (more or less) "catches" the fan blade as it exits the case. What you can't contain is a fan disk or a turbine disk. There's just too much energy involved to contain a disk. When a disk bursts it breaks into three pieces and there's so much energy that you couldn't contain it unless you put in armor plate around the case.

What is troublesome here is that they likely lost a part of a turbine disk attachment and out came more than a few blades. When you are designing turbine blades the blade root is supposed to be weaker than the area under the blade platform (called the blade neck), which is supposed to be weaker than the disk lug. That way if you break something you only let loose a blade airfoil, and that is pretty easily contained. This time they lost multiple blades and the case didn't contain what they let loose. If they had burst a disk the damage would have been enough to cut the engine in half, and that didn't happen, so the issue is why didn't they contain what let go, and why did hardware with this much energy break. When you are certifying an engine you test for containment capability, but this failure wasn't contained, and that's why Quantas is grounding their fleet. It isn't that the engine failed, if an engine failed but was contained, it isn't a big deal. But it's a problem here is that it wasn't contained and it should have been.

 

Solofast- Affirmative. Whatever criteria they used for the turbine sections was insufficient to do the job for the type of failure they had. Scary stuff with engines that large.

Taz
Terry Phillips

 

The only requirement is to contain the front blades, mostly in case of FOD or birds. It worked perfectly on the A320 which ditched in the Hudson river: the engines shut down as they are designed to do to avoid an uncontained explosion.

Read this, kinetic energy can be a b*tch...:

http://forums.jetcareers.com/general-topics/69275-american-767-uncontained-engine-failure.html

 

Hi Taz,hope all is well.
CEO of Qantas reckons there was no danger!
1 blade rips into the wing,80 others God knows were,fuel leaking out anf they were unable to shut the engine down.
Sad thing is weither its RRs fault or not,QANTAS no longer carry out major maintance down under.