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A380 engine failure - Qantas

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A380 engine failure - Qantas

Old 4th Nov 2010, 18:49
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A380 engine failure - Qantas

So engine failures are not uncommon in aviation today, but this one Nov. 4th on the Quantas flight involved engine parts that breached the wing structure and at least one engine could not be shut down.

Is it likely that this chain of events was not contemplated in the planning stages and that it will now require a re-design of the systems in the aircraft?

How many A380s with this engine are in service now?
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Old 4th Nov 2010, 19:00
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Perhaps it would be a better start to what could become a long thread, to go back and change the spelling of Quantas to Qantas - an acronym of Queensland and Northern Territory Aerial Services Limited.

mm43
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Old 4th Nov 2010, 19:50
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There was a video out there showing that only half the spoilers actually deployed on touchdown. Was it because the half happened to be powered by the hydraulic system that was lost or was engine 1 running beyond idle as Teh reason?

Just wondering!
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Old 4th Nov 2010, 21:23
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Much of what happened was anticipated in the design. Sure some new facts will emerge and even some new lessons learned.

I hesitate to get ahead of the facts with predictions but I am well aware of the "what-ifs" and that even worse has and can happen.

It's the new lessons available for learning that I am most interested in So I will continue to follow the new facts part of threads
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Old 5th Nov 2010, 12:51
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From an investors standpoint, is this likely to be a set back for the AIrbus parent company and RR?
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Old 5th Nov 2010, 14:08
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Well American engines might not be so fuel efficient as the British engines, but they are necessarily more idiot proof because needs to consider the end user.

in times of FADEC it is not an issue anymore i think.
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Old 5th Nov 2010, 14:12
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Not as fuel efficient as American engines? Give me a break. FedEx is now flying China-Memphis with full loads and soon to start Beijing-Memphis. Try that with the bloated whale. I do not know how long they are in the air but I bet it is close to 16 hours. FedEx dropped the whale, for what reason I do not know, but I bet they are glad they did.

Last edited by 3pointlanding; 5th Nov 2010 at 14:15. Reason: additional information
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Old 5th Nov 2010, 14:41
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I'm sure right now there's an army of engineers at Airbus pulling their hair out. I HOPE this was a unique case due to the environment or another particular issue.

If it turns out this is a design issue, Airbus is screwed.
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Old 5th Nov 2010, 14:50
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If it turns out this is a design issue, Airbus is screwed.
Utter rubbish
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Old 5th Nov 2010, 14:59
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I'm not an engineer but I would have thought the aircraft design should have anticipated engine failures like this and that the issue involving the inability to shut off other engines and or the loss of hydrolic pressure in this incident would be more problematic for Airbus than RR.


Thx.
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Old 5th Nov 2010, 14:59
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Could we please stick to technical discussions here, like questions and how technical things things work.

All other opinion discussions fit quite nicely in Rumours & News items.
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Old 5th Nov 2010, 15:03
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I would have thought the aircraft design should have anticipated engine failures like this and that the issue involving the inability to shut off other engines and or the loss of hydrolic pressure in this incident would be more problematic for Airbus than RR.

The design does consider such things under the regulations. Some of the design assumptions take into account the muliplicity of means to shut off the fuel as well as the means to have sufficient control of the aircraft to still land .

Seemed to work in this case
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Old 5th Nov 2010, 15:04
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ADs affecting the 380 ?

AD 2010-16-07. RB211-Trent 970-84, 970B-84, 972-84, 972B-84, 977-84, 977B-84, and 980-84 turbofan engines. These engines are installed on, but not limited to, Airbus A380 series airplanes. Wear of shaft rigid coupling on several engines during strip. Earlier history; Refer to MCAI EASA Airworthiness Directive 2010-0008, dated January 15, 2010, for related information.
AD source and Link > Rolls-Royce plc (RR) RB211-Trent 900 Series Turbofan
===============
AD 2010-17-13. RB211-Trent 970-84, 970B-84, 972-84, 972B-84, 977-84, 977B-84, and 980-84 turbofan engines. These engines are installed on, but not limited to, Airbus A380 series airplanes.
To detect cracks in the low-pressure turbine (LPT) casings, which could result in the release of uncontained high- energy debris in the event of a stage 1 blade failure.
AD source and Link >
Rolls-Royce plc (RR) RB211-Trent 900 Series Turbofan
================

Two ADs for other models - but with similar causes. Vent tube blockages.

AD 2010-06-14. 700s series has a problem similar to 800s series. (Boeing 777s) Could this same problem extend to 900s series on A-380s ?
The Trent 800 has a similar type design standard to that of the Trent 700 and has also been found in service to be susceptible to carbon deposits in the oil vent tube. We are issuing this AD to prevent internal oil fires due to coking and carbon buildup in the HP/IP turbine bearing oil vent tube that could cause uncontained engine failure and damage to the airplane.
AD source and Link > Rolls-Royce plc RB211-Trent 800 Series Turbofan

AD 2010-07-09. RB211-Trent 700 Series. This AD supersedes AD 2007-02-05. These engines are installed on, but not limited to, Airbus A330-243, -341, -342 and -343 series airplanes.
Background; This AD results from further analysis that the cleaning of the vent tubes required by AD 2007-02-05 could lead to loosened carbon fragments, causing a blockage downstream in the vent flow restrictor. We are issuing this AD to prevent internal oil fires due to coking and carbon buildup that could cause uncontained engine failure and damage to the airplane.
AD source and Link >
Rolls-Royce plc RB211-Trent 700 Series Turbofan
=====================

Another AD for 900s series but no mention of uncontained explosion.

2009-18-13; Title: Rolls-Royce plc. (RR) RB211 Trent 900 Series Turbofan Engines
We are issuing this AD to prevent the release of a high-pressure (HP) turbine blade, which could result in an engine power loss or in- flight shut down of one or more engines, resulting in an inability to continue safe flight. Evidence from development testing and flight test Trent 900 engines has identified cracking on some HP Turbine Nozzle Guide Vane (NGV) Convex Surfaces.
AD source and Link >
Rolls-Royce plc. (RR) RB211 Trent 900 Series Turbofan
=================

Other ADs in a related model ( 800s series) with a mention of uncontained explosion.

2001-26-11; Title: Rolls-Royce, plc RB211 Trent 800 Series Turbofan Engines
LPC fan blade failure due to cracking, which could result in multiple fan blade release, uncontained engine failure, and possible damage to the airplane.
AD source and Link >
Rolls-Royce, plc RB211 Trent 800 Series Turbofan
===============
End
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Old 5th Nov 2010, 15:40
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lomapaseo

Some questions come to mind. If the IP disc self ejects, are we looking at a disc failure as the cause? Or is it more along the lines of the "Rigid Coupling" feature, which I am assuming is the disc's bearing mount on the shaft? Generally, with turbine engines things get heavier and more robust as the Rotating mass approaches its center, the shaft, itself.

since heavier and more massive assemblies cause more damage when they fail, how specifically is this incident impinging on this model's maintenance and service life ?

Also, my intuition is that Intermediate Turbine is the focus of high acceleration and pressure increase of the air mass, could excess bearing wear be caused by engineering insufficient to contain this stress? Also, could you explain the oft misunderstood difference between the Turbojet and the TurboFan?

Thanks, bear
 
Old 5th Nov 2010, 20:24
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EASA Airworthiness Directives Publishing Tool ..... this might be the cause..
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Old 5th Nov 2010, 20:55
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Bear

All avenues of investigation against all causes remain open at this time. Since I have'nt even seen what failed or any clear pictures of a closeup of the engine or recovered rotor parts I can't speculate and add any value to the understanding regarding a specfic incident under current investigation (nothing releasable)

I'll probably get back to you later on this when I have the time, to answer generalalities
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Old 5th Nov 2010, 22:20
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one passenger reported a hole thru the winfg with wires and cables flapping around in it
isnt there supposed to be a scrapnel shield to stop stuff being thrown out and hitting the wings?
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Old 5th Nov 2010, 23:03
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yotty

nice catch. Short of conclusive, but certainly tracking well (it would seem), to the end result. The terminology is not yank so I infer the "Coupling interface" to mean a thrust bearing.

Thrust, received by the face of the Shaft's shoulder, and negative thrust, if the engine is barfing, must be absorbed through a range of values, including vibration and high energy harmonics. The AD is a follow on to an original, perhaps not in time to preclude this event, even though the inspection alone creates problems relative to mitigation, and might be under "Pressure" to be declared "Deferrable".

Any repair would be a replacement of the disc and possibly the shaft. Time consuming, and expensive, to include a/c out of service. Leases don't take vacations.
I have seen a Shaft set of splines rub the disc face smooth, (generally the Shaft metal is treated to be more wear resistant than the disc hub). If a lubrication issue, flow restriction is necessary of the designed kind, but coking and carbon are not in the design consideration.

Is this about what you had in mind?

bear
 
Old 6th Nov 2010, 00:34
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Bear

As promised:

The mass of the released part is not nearly as important as its velocity and the shrapnel that accompanies it.

The idea was to fail-safe it to the point that it was extremely unlikely to fail.

Lots of considerations like; cyclic life, freedom from harmful vibrations, wear, fire and overspeed

Even then the aircraft is designed to minimize the impact to safe landing should the failure of this part occur. (good job there )

So what caused its release

keep track of the photos and press releases for any hints.

Lots is aleady available to the investigators from the recovered parts, although more part searching along the ground may be necessary.

No sense in speculating ahead of some more facts and "what ifs" are just that since the safety aspects are based on minimisation of combinations and not impractical flat out eliminination
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Old 6th Nov 2010, 02:23
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Perhaps an engineer could state how much energy is contained in a Trent turbine wheel at take off power, and better still offer a comparison to something more easily understood.

I take it that the specific impulse would be measured in some reasonable unit like Newton metres, or foot pounds?

Or maybe, it's more like a KE thing?

Or is it a Joules thing? It's been a while since last I was in Mr Stirlings physics class.
 

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