Qantas A380 Engine Failure

[guamainiac]

I hate making a fool of myself in public. Back to our regularly scheduled blather.

[Highkeas]

There is a photo circulating showing half a rotor

http://news.yahoo.com/s/ap/20101108/ap_on_bi_ge/as_qantas_emergency_24

As a participant in several investigations I find it horryfying that this item is lying unpackaged over what looks like a drainage grating. It is important to keep evidence protected both from handling damage and loss of vital clues (for example a lot is often learned by something as simple as a soot analysis).

[Tucsonman]

It seems Mr Joyce is worried about the compensation side of things from Rolls Royce and Airbus. It's called W- A- R -R- A- N- T- Y Mr Joyce. If your warranty admin people cant handle it, i certainly will, for 10% of the total return before GST. I will then gladly retire from my current position a very rich man.
PM me when you are ready.

[Evan]

Interesting BBC article here regarding the discovery by Qantas of oil on 3 A380 Trent 900 engines" where oil shouldn't be". Could be a pointer in the right direction and shed some light on last week's incident.

Again, I wonder if this has anything to do with AD No.: 2010-0008R1:

Applicability: RB211 Trent 900 series engines, all marks, all serial numbers.These engines are known to be installed on, but not limited to, Airbus A380 series aircraft.

Reason: Wear, beyond Engine Manual limits, has been identified on the abutment faces of the splines on the Trent 900 Intermediate Pressure (IP) shaft rigid coupling on several engines during strip. The shaft to coupling spline interface provides the means of controlling the turbine axial setting and wear through of the splines would permit the IP turbine to move rearwards. Rearward movement of the IP turbine would enable contact with static turbine components and would result in loss of engine performance with potential for in-flight shut down, oil migration and oil fire below the LP turbine discs prior to sufficient indication resulting in loss of LP turbine disc integrity. Some of these conditions present a potential unsafe condition to the aeroplane.

This AD requires inspection of the IP shaft coupling splines and, depending on the results, requires further repetitive inspections or corrective actions.

You'll notice the AD refers to all Trent 9XX mills, not just the 972.

[Deadstick]

You know of course, I was kidding with the floats comment.

[guamainiac]

Deadstick, I know you were and that film idea is half baked. However that said, aside from corrosion problems and such, I could give a hundred reasons why it won't work. On occasion, however you toss some seemingly wacky idea in the air and someone with talent will take it an run with it. They can transform the sow's ear to the silk purse. All knowledge is synthetic and when something keeps coming back to mind there just may be something. Not for me, I don't have the talent but perhaps for someone else.

[Alpha Sierra]

Again, I wonder if this has anything to do with AD No.: 2010-0008R1:



You'll notice the AD refers to all Trent 9XX mills, not just the 972.

Hmmm...interesting. What's described in the AD does at first glance seem to bear some relevance to what happened last week, or at least to the oil discovered by Qantas on 3 other Trent 900 engines. It would appear that RR have a little problem on their hands, but let's wait and see.

[Evan]

Hmmm...interesting. What's described in the AD does at first glance seem to bear some relevance to what happened last week, or at least to the oil discovered by Qantas on 3 other Trent 900 engines. It would appear that RR have a little problem on their hands, but let's wait and see.

The problem related to this AD was actually identified last year. An original AD was issued on January 15th. An AD in August updated the terms of compliance, but still gave the operators up to 400 cycles (since new) to comply. I don't imagine that the A380 is a high-cycle machine. Therefore, it's possible that Qantas hadn't yet carried out the inspections, but was still in compliance.

But it might be a red herring. Must wait and see...

[Jingogunner]

non-containment

My brother has a business that involves leasing Cessna Caravans. I noticed sitting on his mantle a beautiful piece of craftsmanship that was a gear from a PT-6 engine. I picked it up and it weighed about 20 pounds, but looked pristine. He said it cost about $55k and was out of service due to cycles. That was out of a PT-6. Imagine the size of these same pieces in an A380 powerplant and what happens if one lets go.

If you're saying that the smooth pretty gloss painted outside of the jet engine is for pretty and for airflow, containment is just not feasible, its not a design consideration, all I can say is bugger.

[Jingogunner]

Burst Zone?

The turbine is not supposed to let go. The containment casing is designed to stop blade off events, not complete turbine failures. It is not possible to strengthen a casing sufficiently to stop a turbine failure, which is why the burst zone exists.

I'm struggling a bit here, my background is far away from aviation or engineering, but I find it fascinating. Blade-off is relatively common and containable, but whole turbine failure/explosion comaparatively rare and uncontainable, have I got that right? Am I getting a vague hint that people here are thinking about too many engine problems with the (Trent?) engines on the 380 and that maybe the manufacturers have a little problem or something?

What is the Burst Zone please?

[guamainiac]

You just woke up after a long shift right?

[Evan]

I'm struggling a bit here, my background is far away from aviation or engineering, but I find it fascinating. Blade-off is relatively common and containable, but whole turbine failure/explosion comaparatively rare and uncontainable, have I got that right? Am I getting a vague hint that people here are thinking about too many engine problems with the (Trent?) engines on the 380 and that maybe the manufacturers have a little problem or something?

What is the Burst Zone please?

A dry area (no fuel tanks) of the wing adjacent to the engine pylons, where damage from an uncontained engine failure is most likely to occur. Known as 'rotor disc burst area'.

[Alessandro]

This is what I think will happen, the whole left wing will be replaced, an AN-225 will fly in the spare wing taken from VH-OQK and the Beluga will fly in all the extra jigs needed for a wing replacement.

[Deadstick]

Save the money and the hassle. Use duct tape.

[guamainiac]

Evan, don't add your own "dry" definition to that. It seems there is a burst area by design and a real burst area.

It is going to be hard to convince me that per your diagram, the design confined the burst area to the dry portions of the wing hence my "believe in angels or angles" comment. A bit more forward speed and thrust and perhaps that burst area could have changed the topic of this thread. Just the surface area of a component could alter the path of some metallic asymmetric frisbee and how many feet or inches were those shard from missing the wet section?