Qantas A330 Emergency Landing in Learmonth
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From the ATSB briefing:
"...it is important to note that in fly by wire aircraft such as the Airbus, even when being flown with the Autopilot off, in normal operation, the aircrafts flight control computers will still command control surfaces to protect the aircraft from unsafe conditions such as a stall."
and
"About 2 minutes after the initial fault, ADIRU 1 generated very high, random and incorrect values for the aircrafts angle of attack.
These very high, random and incorrect values of the angle attack led to:
the flight control computers commanding a nose-down aircraft movement, which resulted in the aircraft pitching down to a maximum of about 8.5 degrees, "
Looks like HAL took over the mothership!
(2001 Space Odyssey reference for those too young to remember).
"...it is important to note that in fly by wire aircraft such as the Airbus, even when being flown with the Autopilot off, in normal operation, the aircrafts flight control computers will still command control surfaces to protect the aircraft from unsafe conditions such as a stall."
and
"About 2 minutes after the initial fault, ADIRU 1 generated very high, random and incorrect values for the aircrafts angle of attack.
These very high, random and incorrect values of the angle attack led to:
the flight control computers commanding a nose-down aircraft movement, which resulted in the aircraft pitching down to a maximum of about 8.5 degrees, "
Looks like HAL took over the mothership!
(2001 Space Odyssey reference for those too young to remember).
Bottums Up
It's a sad indictment of our profession, that in a country once known for giving a bloke a fair go and the benefit of the doubt, so many are so quick to point the finger. 
This is very similar to what happened to the MAS 777 off Perth in 2005. High value outputs from the ADIRU went to the PFCC and away she went. Fortunately the intial response in that incident was positive g but it had the potential to snap the rudder off. The big issue is the lack of effective testing of the software that controls all these outputs. Mathematical testing of the software is possible but considered expensive and time consuming.
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Three ADIRUs ?
If there are three ADIUs onboard - as per the ATSB media release - Why did a fault in one cause a major upset?
I thought perhaps there were three for voting purposes? And that the failure in one would be noticed and the data ignored in favour of the two remaining units.
There has to be something more to the story than released so far.
I thought perhaps there were three for voting purposes? And that the failure in one would be noticed and the data ignored in favour of the two remaining units.
There has to be something more to the story than released so far.
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I agree, I think they release only what they do know as fact.Other stuff will come out in due course when facts become apparent imho.
There must be other failures to allow this imho.
There must be other failures to allow this imho.
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ADIRU's
The real concern would now logically be, determining how one wayward ADIRU managed to disable and bypass a multitude of protections designed to prevent such a flight disturbance.
The following protections appear to have been ineffective in this instance,
*Load factor limitation
*Pitch attitude correction
*High speed protection
*Maneuver load alleviation(MLA)
*Turbulence damping function
*System Redundancy
I dare say, the serviceability and DDG relief regarding this component will be reviewed without delay.
The following protections appear to have been ineffective in this instance,
*Load factor limitation
*Pitch attitude correction
*High speed protection
*Maneuver load alleviation(MLA)
*Turbulence damping function
*System Redundancy
I dare say, the serviceability and DDG relief regarding this component will be reviewed without delay.
Last edited by Acute Instinct; 14th Oct 2008 at 21:44.
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Fair Go
Have to agree with Capt Claret, especially after listening to ABC AM this morning where the preliminary ATSB report says that the incident was the result of computer malfunctions and that the actions of the pilots were correct in every detail. Furthermore, the attempts by Qantas Engineering staff to blame off-shore maintenance was described as "scurrilious" and that QF off-shore maintenance was conducted by world class facilities. Let's hope the detractors of both the crew and the maintenance say a collective "Sorry". BTW, the aircraft was flown to Sydney overnight.
I would think that a software upgrade installed to fix one problem has inadvertantly caused this problem. As I mentioned previously, testing of software is not as precise a science as structural testing where the failure paths are obvious.
Nunc est bibendum
Old fella, this is how the Australian said 'sorry' for their previous article about pilot error.
A stand alone sentence at the end of the article here.
The findings quash any suggestion of pilot error.
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old fella
where and who from Qantas Engineering staff blamed OS maintenance pls?
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Finger pointing
ampclamp, I am unaware of any specific Qantas Engineer blaming off-shore maintenance as being the cause of the QF72 incident. My reference was to what was stated on ABC AM today. The report said in part "the scurrilous attempt by Qantas Engineers to blame off-shore maintenance". I have defended off-shore maintainers, namely HAECO particularly. My reference to an apology was to anyone who has pointed the finger at either the flight crew or maintenance staff. That said, anyone who listens to news broadcasts knows Qantas Engineering Union reps have been critical of off-shore maintenance being inferior, a generalisation which I personally think is unjustified.
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Old fella
I do't wish to enter into a slanging match and I am operating off both first and second hand experiences here.
A very recent conversation with a QF LAME who had extensive periods "liasing" in two off shore MRO's of QF's choosing was aghast at some of the practices he saw and had to have corrected before allowing the job to continue.
He says he lost count of the number of times he had to summons the local Quality representative to right the wrongs and in his words the local tradesmen, invaribly not licensed, would appear to not even know of or use the standard practices as set out in the AMM's.
So I'll agree with some of the other various posts on this site that SOME of the MRO's leave a lot to be desired with SOME of their respective maintenance practices rather than blanket statment that they are all as bad as one another.
And I am in no way suggesting that the latest incident on QF72 was off shore MRO related, lets wait for the investigation to be completed.
A very recent conversation with a QF LAME who had extensive periods "liasing" in two off shore MRO's of QF's choosing was aghast at some of the practices he saw and had to have corrected before allowing the job to continue.
He says he lost count of the number of times he had to summons the local Quality representative to right the wrongs and in his words the local tradesmen, invaribly not licensed, would appear to not even know of or use the standard practices as set out in the AMM's.
So I'll agree with some of the other various posts on this site that SOME of the MRO's leave a lot to be desired with SOME of their respective maintenance practices rather than blanket statment that they are all as bad as one another.
And I am in no way suggesting that the latest incident on QF72 was off shore MRO related, lets wait for the investigation to be completed.
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To continue the thread drift. I think JetA_OK has nailed it.
Professional LAMEs only trust their own work, and will scrutinise anyone else's with an intense scrute. That is an essential part of the safety net. As it should be, and thank goodness for it.
Problems arise when industrial stoushes raise emotions. In that environment things are said, which should not be said, and the reputations of other MROs are attacked.
Reality is that, rarely, things get overlooked in any hangar, but the net normally catches them because professional LAMEs only trust their own work. (See above)
Professional LAMEs only trust their own work, and will scrutinise anyone else's with an intense scrute. That is an essential part of the safety net. As it should be, and thank goodness for it.
Problems arise when industrial stoushes raise emotions. In that environment things are said, which should not be said, and the reputations of other MROs are attacked.
Reality is that, rarely, things get overlooked in any hangar, but the net normally catches them because professional LAMEs only trust their own work. (See above)
So when will Channel 7 stop using the horribly innaccurate animation of a A330 making a death plunge? Seriously, I hope at least lame duck Media Watch pulls them up for using such an inaccurate depiction of the event.
Does nothing but give the punters the wrong idea...
Does nothing but give the punters the wrong idea...
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Off-shore MRO
Bumphfoh, You are not getting into a slanging match. I have much respect for the quality of home grown QF maintenance from my own experience of it. Equally I have the same respect for the maintenance performed by HAECO on Cathay aircraft when employed by Cathay. My point is that it is unfair to generalise in being critical. If the QF LAME with whom you spoke is telling it as it is, then it behoves him to make his case to the Director Engineering, which I am sure he would have done. I would also hope that whomever Qantas engage off-shore, the engineering staff have the final say and not the bean counters. As Wod points out, JetA_OK has hit the nail on the head. Professional jealousy will always lead to one outfit being critical of another. If justified, criticism is OK, if not it is unfair. That is my point.
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Computers either work, or crash. They don't head off into their own little netherworld.
Also a double MCDU failure but not on the same flight, I must have bad luck.
And NO, they weren't Qantas Aircraft.
MC
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I was interested the other day in one of the media blurbs about the first QF 380.
It was something like.... if there was a (total?) hydraulic failure there would be no problems because although the pilots might not be able to fix it the computers could still fly the aircraft...everything would be OK.
No we are told that in certain circumstances a computer can cause an incident such as experienced by the 330 from Singapore....
Are we heading for a situation where new aircraft are computer driven instead of computer assisted and if so is this a cause for concern?
It was something like.... if there was a (total?) hydraulic failure there would be no problems because although the pilots might not be able to fix it the computers could still fly the aircraft...everything would be OK.
No we are told that in certain circumstances a computer can cause an incident such as experienced by the 330 from Singapore....
Are we heading for a situation where new aircraft are computer driven instead of computer assisted and if so is this a cause for concern?
Furthermore, the attempts by Qantas Engineering staff to blame off-shore maintenance was described as "scurrilious" and that QF off-shore maintenance was conducted by world class facilities. Let's hope the detractors of both the crew and the maintenance say a collective "Sorry". BTW, the aircraft was flown to Sydney overnight.
I reckon media watch should have a listen because to claim that you are independent then spend the whole interview blowing smoke up QF and rubbishing the engineering department you would have to seriously question ones motives. Since when had anyone blamed overseas maintenance on this anyway?
Here is part of the transcript from AM Wednesday 15th October
Geoffrey Thomas is the senior editor at Air Transport World.
GEOFFREY THOMAS: The extraordinary thing about this is that there was a similar failure in a Malaysian airlines 777 in August 2005, off coast of Western Australia and in almost identical position, and it similarly caused the pilots enormous problems and they had to bring the aircraft back to Perth and at one stage they almost lost the aircraft.
RICHARD LINDELL: No decision on the future of the aircraft has been made, although it was flown back to Sydney last night suggesting the incident didn't cause structural damage.
Geoffrey Thomas says the A330 has an excellent safety record and passengers shouldn't fear the Airbus nor maintenance standards at Qantas.
GEOFFERY THOMAS: There has been what I would call a scurrilous campaign run by its engineers, supporting a higher pay rise and job security, and I can understand those issues.
But when they talk about and blame offshore maintenance for these woes, it is absolutely totally incorrect because the offshore maintenance done by Qantas is done at some of the most reputable centres in the world, and there is just no question about the quality of the maintenance done overseas.
GEOFFREY THOMAS: The extraordinary thing about this is that there was a similar failure in a Malaysian airlines 777 in August 2005, off coast of Western Australia and in almost identical position, and it similarly caused the pilots enormous problems and they had to bring the aircraft back to Perth and at one stage they almost lost the aircraft.
RICHARD LINDELL: No decision on the future of the aircraft has been made, although it was flown back to Sydney last night suggesting the incident didn't cause structural damage.
Geoffrey Thomas says the A330 has an excellent safety record and passengers shouldn't fear the Airbus nor maintenance standards at Qantas.
GEOFFERY THOMAS: There has been what I would call a scurrilous campaign run by its engineers, supporting a higher pay rise and job security, and I can understand those issues.
But when they talk about and blame offshore maintenance for these woes, it is absolutely totally incorrect because the offshore maintenance done by Qantas is done at some of the most reputable centres in the world, and there is just no question about the quality of the maintenance done overseas.
Last edited by neville_nobody; 15th Oct 2008 at 11:05.