Renamed & Merged: Qantas Severe Engine Damage Over Indonesia

[Oakape]

Is a software glitch any more concerning than a rudder hardover? Or fuel icing flaming out both engines?

I would have to say yes. A software glitch can be much more difficult to prove/find/replicate, and is therefore harder to fix. It can also manifest itself in many different ways, making it difficult to develop procedures to deal with the problem before the fix is found & implemented.

It has also been my experience that engineers tend to dismiss these sort of problems as 'finger trouble' on the part of the pilot. If the machine & it's computers are designed not to do something, people find it hard to accept that it can actually do the very thing it was designed not to do.

A number of years ago I was flying the 767. In the cruise, when you changed the altitude in the MCP, the selected altitude would appear in the FMC scratchpad. This would make it easier to make the change to the cruise altitude in the FMC - just line select it in & execute. We were told that the system was designed to only send the signal one way - from the MCP to the FMC. A signal couldn't travel the other way, from the FMC to the MCP.

Well it happened to me not once, but twice. An altitude appeared in the scratch pad without any pilot input & then the MCP altitude changed to match. The first time I didn't immediately notice the MCP change, as I was looking at the FMC wondering how the altitude had magically appeared in the scratch pad. The second time it happened (different day, different airframe) I immediately looked at the MCP & witnessed the digits in the altitude window rolling to match the altitude in the FMC sratchpad.

[oicur12.again]

The 767 was developed when the Vic20 was flashmate and the commodore 64 was a dream.

"A number of years ago"

I suspect times have changed in aviation software too.

[breakfastburrito]

Originally Posted by AnQrKa

Welcome to the new world. Is a software glitch any more concerning than a rudder hardover? Or fuel icing flaming out both engines?

AnQrKa, the issue with software vs mechanical is this.
Whilst no watch maker, I'm sure there would be relatively few "classic" watch mechanism designs - a function of the physical nature of the mechanism. Even a new design would be easily understood by an expert watchmaker who had not seen it before, and its design limitations would be relatively easy to imagine.

However, software is infinitely variable, precisely because it is not limited by the physical - it is only limited by the imagination of its creator. On the one hand this offers an enormous opportunity to free a device from the physical world's constraints. However, there are downsides. Complexity & lack of standardisation. Whilst there are coding principles & techniques, looking over thousand, or hundreds of thousand of lines of code & abstracting that back to a complex working program is not what the human brain does well. A new software engineer looking through code may not pick up a critical, but subtle flaw. Further, unlike a mechanical device that literally has thousands of ground engineers examining a component out on the line, monitoring performance & noticing flaws, software "black box" solutions have a limited number of eyes to examine the code.

It is not obvious that flaws in software can lurk for years or decades prior to discovery. Developer fixes 33-year-old Unix bug.

This is software's Achilles heel, the promise of infinite variability leads to the consequence of infinite complexity.

[Sunfish]

what would have happened if the disk had gone into the electronics bay and taken out the computers?

[airtags]

Sunfish - your pitch is quite valid although a few people would be no more if the debris got that far (let's not mention where the avionics are located)

The extent of the damage to OQA, including the loss of so many essential systems is undeniable testimony to the fact that you just can't isolate 'the engine' as the risk and mitigate it by proclaiming a 'band aid' software patch.

The incident has also identified a number of other risk potentials/flaws in the redundancy fetures of the aircraft's design.

Aside from the sidebar questions about what prior knowledge of the risk that RR/QF & ors., had - the significant questions now relate to the integrity of the "fix".

These questions include: (journos pls write them down for use at the next AJ stand up)

1. Given the 380's history of software problems - everything from main gear, cabin pressure, to emergency lights, what aceptance (flight) testing and assurance will crew have that the 'patch' will actually work?

2. Will the 'patch' override pilot command? (remember the 330 !!)

3. Will the software be tested in flight inc., in non routine events? - In such circumstances whose cmds are subordinate - pilot or software?

4. Even with a change of the type of seals used, the physical design of the engine remains unchanged, therefore the actual risk still remains. Will QF abandon it's risk matrix & SMS protocols in order to put the 380's back up?

5. Assuming the current A.D. remains, QF will be self managed in the prescribed checks. Will it be done every 10 cycles, or will it be taken out to the max 20 cycles?...or in the absence of Regulatory oversight, will it slip (as is the QF way) due to operational needs? (eg., OQF and the tea towel in the door fix last April)

6. Who will carry out the inspections - can RR & QF be trusted to self audit? The pressure to sign out an aircraft is already immense.

7. What is QF's position if further adverse findings are made during an inspection after reinstatement of operations? - will the fleet be immediately grounded or will they roll the dice and hope it is still a 'one off'?

8. The 'rolling reinstatement of ops' that QF internally is running with 72 hour status reviews, suggests that pending RR, QF will seek to return the 380 to ops prior to the ATSB interim report. This raises questions in connection with the effectiveness of the CASA/ATSB joint Regulatory environment.

9. Was told that last week QF advised CC that the soon to be delivered a/c 7, 8 & 9 all have "already received the RR mods and the a/c have been 'tested' and approved?" - When was the mod carrid out?, When was it tested and what was the test methodology? Given the conditions of the current A.D., who has approved it?

It certainly seems that the underscore will be more about trust and integrity - two things that are a little light on at Q these days.

AT

[Oakape]

The 767 was developed when the Vic20 was flashmate and the commodore 64 was a dream.

"A number of years ago"

I suspect times have changed in aviation software too.

I was simply using something I have personally experienced, rather than hearsay, to illustrate a point.

I don't suspect that times have changed - I know they have. However, I don't believe that the issue I was talking about has changed at all.

oicur12.again, perhaps you should take a couple of steps back & have a look at the forest.

[Helmut Smokar]

A software patch that prevents the engine getting to the point of disk fracture has to be a plus, I guess it probably looks for indication of turbine overspeed and idles the engine hopefully prior to disintegration?
Given the catastrophic results of such a failure, even if they are rare, I'm ok with it

[QFBUSBOY]

There has not much mention being made of the previous Qantas management under Geoff Dixon's stewardship that put in place this train of events. All these woes are as a result of decisions that were made in the previous 5 to 10 years.



If you outsource your maintenance, always take the lowest quote possible, let your money making machines leave Base & Heavy Maintenance with deferred items in the Tech Log, then this was always going to be the result.



Qantas management thought that the Engineers industrial action did major damage to the brand, well its about time that they shoulder the blame for this debacle. This is far worse in terms of damage to the airline. The root problem is not the A380, it is a culmination of top management decisions related to running the airline. Its everything from pilots, to cabin crew, to engineering,to ramp staff, to cleaners,to check in staff, etc. This list goes on. It is having managers in engineering who have no engineering background, but rather Bachelor of Arts majoring in Australian History. It is this sort of people we have running an airline. I am not saying that they don't try to do the right thing, but you have to question the reason for people with no technical knowledge in positions of managing a business that is highly reliant on knowing what the outcomes are for not managing your equipment properly. It is understandable that the CEO is not a pilot or engineer, but when your middle management don't have the right qualifications for the position, then it is only a matter of time. Alan Joyce and previously Geoff Dixon have gone on the record stating that these new aircraft require less maintenance. I don't know if they have noticed, but geez, all the engineers I know have never been so busy. If this is how they are brand new, God help us when they start to age and require Major Maintenance. I am sorry to say, but we as employees are in REAL trouble for the future.



Its always great to have the newest toy on the block, but when it doesn't perform as advertised and you don't seek proper recompense for what damage is being done to the brand, then you would expect staff and the public to lose faith in the managers making these critical decisions. Maybe its time to really listen to some of your staff on the floor, and not your Yes men/women, and stop paying lip service through Employee Engagement Surveys. It might also be a good idea to trot out some of your Senior pilots and engineers to explain what is really happening to your aircraft. Sorry Alan, but some of your explanations of Technical detail leave a lot to be desired. It might sound good to the media(who have no clue) but even Technical people can explain things in layman's terms. In my own opinion, Qantas would look far more professional if the explanations were from experts in their field, and not from people who have no technical knowledge.

[Short_Circuit]

QFBUSBOY,

A realistic statement of the state of affairs. A lot unsaid though.

Any word of the OQA wright off / buy back?

[ALAEA Fed Sec]

Nice post bus boy.

In short, Alan and his spokesmodel keep saying that this is not a maintenance issue. It is.

This issue is about maintenance that was not carried out.

[601]

It has also been my experience that engineers tend to dismiss these sort of problems as 'finger trouble' on the part of the pilot. If the machine & it's computers are designed not to do something, people find it hard to accept that it can actually do the very thing it was designed not to do.

We had a omega nav system that would display and indicate us on a track that was in the opposite direction to our planned and actual track. The catch was that it only happened from one location that we flew out of on a weekly basis. The fault did not appear at any other departure points The manufacturer said it was impossible - could not happen.

If the unit was reset after departure it would then work fine.

Trouble was we could replicate the fault on every departure from this particular location. We recorded the lat.long readings over several flights and passed them on to the manufacturer. They asked for the unit and we received a new replacement unit.

No explanation was forthcoming.

So software can have hidden bugs that the developers cannot foresee.

How many time have you sat at a computer and wondered "why did it do that"

A pilot will to react in a particular situation an a certain way, based on their training, knowledge and experience. A computer programmer may have the knowledge to program a system for x number of foreseeable events. But as we know there is always a situation that comes out of left field you will need experience for.

[Sunfish]

The European airworthiness directive was issued in January 2010. It required repetitive inspections of the IP turbine splined coupling, measurement of the amount of meat left in it and requirement for further inspection or engine replacement as a result.

Did QF carry out these inspections? Were RR supposed to carry them out? Were they performed at all? What were the results of the inspections? What decisions were made by QF and/or RR as a result of these inspections assuming they were carried out? Did QF make a decision at all? Was it RR's call?

Exactly who is responsible for what? What did they know, and when did they know it?

Exactly what is going on? The silence is deafening.

[airtags]

Fed Sec
100% on the money ($afetyfirst!)

Theissue is now not only that maintenance was not done, but moreover how can passengers and operating aircrew be assured that it will will be in the future.

Just like if the car comes back from the carwash with smears on the windscreen - you start looking to see what else has been missed.

AT

[empire4]

Just watched a video of 747-800 pax version going together.....I wonder if Qf will wake up to themselves and make an order. The Jumbo has been serving the airline proudly for how long? maybe they should buy a few russian aircraft next!

[topend3]

all of the above questions will no doubt be answered in the final atsb report I would presume? will make for interesting reading...

[The Professor]

FedSec

"This issue is about maintenance that was not carried out."

Every airline defers maintenance. It is not illegal.

Are you suggesting that QF deliberately ignored a directive from the manufacturer to undertake a rectification that would have prevented the A380 incident?

[PACIFIC BARON]

Another 7 Qantas engines to be replaced

from the Brisbane Tmes

THE British jet-engine maker Rolls-Royce has told Qantas that it is likely to have to replace another seven engines on its A380 superjumbo fleet after inspections found the potential for oil leaks. Singapore Airlines is also believed to have been informed that it will have to change up to 20 of the Trent 900 engines used on its fleet of 11 A380s, while the German airline Lufthansa faces two replacements.
The latest advice from Rolls-Royce means up to 29 replacement engines will have to be found. It confirmed on Friday that the failure of a ''specific component in the turbine area of the engine'' on a Qantas A380 on November 4 shortly after take-off from Singapore caused an oil fire that led to a turbine disc exploding.
The need for replacement engines creates headaches for the three airlines whose A380s are powered by the Rolls-Royce Trent 900s due to a lack of spares. Because the A380 superjumbos are such new aircraft, Rolls-Royce and the aircraft manufacturer Airbus do not have a ready supply of engines. Qantas has already had discussions with Airbus and Rolls-Royce about obtaining replacement engines should they be required, placing it ahead of Singapore Airlines and Lufthansa. However, the likelihood of further engine changes means it could take longer for Qantas to return its A380s to service and cost it more in lost revenue.
''The longer it goes on the worse it gets for them - they don't want those planes out of service for too long,'' an analyst said. Qantas has so far replaced three engines on three separate aircraft since it grounded its A380 fleet on November 4 but has been told by Rolls-Royce that it could have to replace as many as seven more. Even if some do not have to be changed, engineers are likely to have to make modifications to the engines.
Singapore Airlines grounded three A380s last week to allow for three engines to be replaced. Two of the aircraft have since returned to service while the engine change to the other A380 is almost complete. It takes up to 36 hours to replace an engine.
A spokesman for Singapore Airlines, Nicholas Ionides, said last night that he could not ''speak definitely'' about the number of engines that might have to be changed because investigations had not been completed.
Qantas said it was continuing to inspect engines on its A380s to meet the requirements under the airworthiness directive issued last week by the European Aviation Safety Agency.
Meanwhile, air-safety investigators have discovered that the audio from QF32's cockpit voice recorder at the time of the engine failure has been lost. The safety bureau said the audio was overwritten because the recorder, which is on a continuous loop, taped the pilots for more than two hours after the engine blew.
A bureau spokesman, Richard Batt, said the loss of the audio was not a significant issue.

[PACIFIC BARON]

Rolls-Royce's A380 engines to be removed for oil fix

from The Australian, by Steve Creedy

ABOUT half the Rolls-Royce Trent 900 engines powering Airbus A380s, including 14 Qantas engines, will need to be taken off and dismantled.

The process would fix components involved in a potentially dangerous oil leak.
The Australian has been told about 40 engines on the 20 A380s operated by Qantas, Singapore Airlines and Lufthansa need to be modified to fix the leaks. This includes 24 at Singapore Airlines and two at Lufthansa.
The modification, described by Rolls-Royce as the replacement of a module and understood to involve a bearing box, requires the engines to be taken off the wing and stripped down so engineers can access the affected area.
Industry players expect the work to strain both resources and parts availability and say the British manufacturer is looking at establishing stations around the world to do the work.
The modifications aim to prevent a repeat of an oil fire blamed for the disintegration of a turbine disc that saw a Qantas Trent 900 rip itself apart, peppering the wing of an A380 with shrapnel and causing substantial damage.
Rolls also plans to introduce a software fix that will shut down the engine before it reaches a point where the turbine disc is in danger of disintegrating.
The incident prompted Qantas to ground its A380 fleet and the airline was still unsure yesterday about when the superjumbos would resume flying.
It expects the A380s to be returned to service on a plane-by-plane basis and Airbus has offered to help by taking already modified engines from its production line and shipping them to Qantas.
A spokesman said Qantas would work with both Airbus and Rolls-Royce to work out "the fastest and most effective way of ensuring its engines were up to the latest variation".
Singapore, which has grounded three planes and has the oldest A380s as well as the biggest fleet of 11 aircraft, would not confirm the number of engines requiring modifications.
A Singapore spokesman said the airline was continuing to inspect the engines in accordance with a European airworthiness directive that allowed operations to continue safely.

[satos]

Meanwhile, air-safety investigators have discovered that the audio from QF32's cockpit voice recorder at the time of the engine failure has been lost. The safety bureau said the audio was overwritten because the recorder, which is on a continuous loop, taped the pilots for more than two hours after the engine blew.A bureau spokesman, Richard Batt, said the loss of the audio was not a significant issue.

Yeah right!
It was not a significant issue because the aircraft returned safely.
If it had crashed I'd bet he wouldn't be using those words.
Another question.
What will be come of the aircraft.
Is the the damage it sustained repairable as I have heard the front wing spar might of been damaged.

[UnderneathTheRadar]

Yeah right!
It was not a significant issue because the aircraft returned safely.

ummm, if they'd crashed, the recording wouldn't have continued......