Breaking news - Qantas A380 in trouble near Singapore

**Hay Ewe** · 5th November 2010, 08:32 AM

Morning all, well the media will be having a filed day with this one

With an aircraft that young, I doubt that the engine has been removed since it was installed at build.
Even it had been removed, I very much doubt it would have been stripped down to any extent for work done at a deep level inside the engine. Because of that, I would agree that maintenance is not an issue and more likly a manufacturing fault or ingestion of some kind. I dont know how long it had been airbourne birds don't usually fly higher than 5000feet (though in the mid 80's a vultre flew in to a 767 at about 15,000feet)

On aircraft of this nature, the failure rate is measured at a rater per 1000 hrs of operation, across the fleet and then across whole world wide fleet - of that same example.
So, whilst there may be 50 A380 in service, there are 200 engines. if each engine does 16 hrs a day that is 3200hrs a day. The fleet is getting on for having been in commercial operations now for two years, lets call that 18months thats 18months times 30days equals 540 days, 540 times 3200hrs equalls 1,728,000 hrs. so the engines in service have accumulate tht many hours so far.

so inconclusion, we have (that I am aware of) 1 decent failure in 1.72 million hrs of commercial flying. rate per 1000hrs = 1*1000/ 1,728,000 = 0.000578
This figure will get smaller as the fleet increases and matures.

Compare this only 30 years ago, and I think you will find that it has improved hugly.

We must also consider the mode of failure. and engine shut down because of a blade separation, lost oil pressure, indication. Three causes to shut down an engine, the first is the most critical, the secound, not so and the third least critical, but all good reasons to shut down an engine.

this similar thinking can be applied to many other things, if some one says, those laughing shafts are always breaking, think, are they? how many of those vehicles do I see, how old are they, how many Km's / Hrs have they done? REALLY how many are broken? whats the rate per 1000 hrs / km's / miles etc

Hay Ewe

**DeanoH** · 5th November 2010, 09:36 AM

I would have thought the inability to shut down one engine after landing is a bigger problem ?

Deano

**VladTepes** · 5th November 2010, 10:54 AM

The enine, designed specifically for the A380 is the Rolls Royce trent 900.

Some info here:
Rolls-Royce Trent - Wikipedia, the free encyclopedia

some other problems wih the engine (allegedly) here:

Rolls-Royce Trent 900 engine linked to three mid-air emergencies | Herald Sun

and a picture:

**wozzlegummich** · 5th November 2010, 03:30 PM

There was an FAA directive issued in September this year to inspect a shaft in the compressor section of all RR Trent 900 series engines for premature wear. If the shaft failed it would allow rearward movement of a turbine rotor allowing it to come in contact with a stator. At the speeds and loads these engines run at on take off I would think that could cause an "uncontained" failure.

**PhilipA** · 5th November 2010, 03:38 PM

At the speeds and loads these engines run at on take off I would think that could cause an "uncontained" failure.

And I would imaging therein lies the problem for RR and why all the other airlines have grounded their fleets.
Everyone remembers Concorde.( ie debris puncturing other bits)
Regard sPhilip A

**VladTepes** · 5th November 2010, 04:14 PM

Originally Posted by PhilipA

And I would imaging therein lies the problem for RR and why all the other airlines have grounded their fleets.
Everyone remembers Concorde.( ie debris puncturing other bits)
Regard sPhilip A

"All the other airlines" haven't grounded their fleets. SingAir has.

Not all A380s are powered by the Trent 900 - some have an engine manyufactured by a joint GE/P&W consortium.

**Hay Ewe** · 5th November 2010, 04:22 PM

funny, I am in the industry albeit different aircraft types, and have only jsut learnt that there were problems affecting #1 eng and wind damage

busy working our fleet to worry about some one elses

Hay Ewe

**VladTepes** · 5th November 2010, 04:27 PM

Originally Posted by DeanoH

I would have thought the inability to shut down one engine after landing is a bigger problem ?

Deano

It wa reported that the number one engine could not be turned off, and a hose from a fire truck poured water into the engine supposedly putting out the fire.

This is almost certainly mostly not true. A pilot acquantance writes:

"From what I've heard, the attempts to drown the engine were just that....attempts. The engine probably decided it was heavy rain, turned on the ignition, and bumped up the idle speed. I don't know how it was shut down in the end."

If more fuel is pumped in, to ensure that the temperature doesn't drop (and it's over 1000°C in those things), then the effect is an increase in the mass flow, and so more power.

**VladTepes** · 5th November 2010, 04:57 PM

Originally Posted by wozzlegummich

There was an FAA directive issued in September this year to inspect a shaft in the compressor section of all RR Trent 900 series engines for premature wear. If the shaft failed it would allow rearward movement of a turbine rotor allowing it to come in contact with a stator. At the speeds and loads these engines run at on take off I would think that could cause an "uncontained" failure.

as you say...

Various FAA Airworthiness Directives re the Trent 900.
Rolls-Royce plc. (RR) RB211 Trent 900 Series Turbofan
most recently
Rolls-Royce plc (RR) RB211-Trent 900 Series Turbofan
for the "potted version" of the above with some explanation have a read of this instead
Qantas A380: A History of Problems With the Rolls-Royce Trent 900 Engines | BNET
(just keep in mind the guy may or may not know what he's talking about).
and then he startsg etting caried away in an effort to fill column inches..
Qantas Grounds A380s After Engine Failure: There’s More to This Story | BNET

**DeanoH** · 5th November 2010, 07:03 PM

Originally Posted by VladTepes

It wa reported that the number one engine could not be turned off, and a hose from a fire truck poured water into the engine supposedly putting out the fire.

This is almost certainly mostly not true. A pilot acquantance writes:

"From what I've heard, the attempts to drown the engine were just that....attempts. The engine probably decided it was heavy rain, turned on the ignition, and bumped up the idle speed. I don't know how it was shut down in the end."

If more fuel is pumped in, to ensure that the temperature doesn't drop (and it's over 1000°C in those things), then the effect is an increase in the mass flow, and so more power.

On this mornings ABC News the pilot is shown telling passengers that he couldn't shut down down an engine.

I don't understand why this is so, inability to shut down engine, maybe the engine control system decided that it was too hot to shut down and went to plan B all by itself for safety reasons or is it that engine management had failed, scary. Either way pouring copious amounts of water into the engine, presumably the one that wouldn't shut down, I would have thought is not likely to do it much good.

Deano

Thread: Breaking news - Qantas A380 in trouble near Singapore

Thread Tools

Bookmarks

Bookmarks

Posting Permissions