TAM A320 crash at Congonhas, Brazil

[Dani]

TripleB, your if"s and when's and why's - you and PBL try to hide the un-nice cause behind all kind of nice words and theories.

This might be usful in a school lesson about logic and mathematical evidence. But we have here a case it couldn't be clearer.

Yes, you're darn right if you say that my reasoning is based on feelings. I feel that force of that engine (two of them) every day, and I know, that if they are not on idle, they pull me forward like crazy!!

Of course they would have been able to stop the aircraft on a longer runway. If their engine would have been in the TOGA detent, they might even have been able to stop it on 10 000m.

If you ask me, you don't see the wood for the trees. This case is so simple it can be: The thrust on engine 2 remained on 1.2-1.3 (PBL would give me 3 digits behind the dot - thaaaank you!), the runway was short and slippery. So what else do you need to discuss about?

Give it up with your far fetched theories. There is only one mistake they did, and that was that TL. Close that thread finally!

Dani <angry>

[PBL]

Originally Posted by lomapaseo

I sure hope that you can't find anything written to support the above.

lomapaseo,

your hope is justified. I was mistaken. The version of Annex 13 which is in force since 1 November 2001 says, concerning the format of the report, "3. Conclusions. List the findings and causes established in the investigation. The list of causes should include both the immediate and deeper systemic causes"

Originally Posted by lomapaseo

The problem that I have with a finding of Probable cause is that it attracts most of the attention to a single item that quite often does not lend itself to responding to a practical solution.

Yes. I would go further. The problem I have with it is that there are usually multiple causes, and multiple systemic causes, amongst the facts that one has selected as being pertinent. (The selection of pertinent facts is another area which lends itself to manipulation and confirmation biases.)

Originally Posted by lomapaseo

The idea behind investigating in the first place is to determine any holes in the swiss cheese

It may be worth pointing out that Reason's model, which has been around for some twenty years now and has shown its worth, is no longer the latest and greatest. The ATSB, which has used it for a decade, has been concerned about its weaknesses and moved to Andrew Hopkins's Accimaps to explain the Lockhart River accident. Accimaps are very similar to Why-Because Graphs (WBGs), but they summarise the factors (so there are fewer nodes: 20-30 instead of 80-100), and additionally classify into categories reflecting whatever general categories of systemic causes one considers to have been pertinent. There is a paper on my WWW site from December 2005 comparing the two methods on the Glenbrook, NSW rail accident.

PBL

[PBL]

Dani,

I may be missing your point, but I am having a problem seeing anything constructive behind your interventions. You have fingered the cause of the accident, and apparently would prefer others not to discuss it further (your comments about closing the thread).

Supposing we appointed you to be the investigating committee, all by yourself. So you can write what your best judgement tells you. What safety recommendations would you come up with "for the purpose of accident prevention and any resultant corrective action"? And how could you persuade us they would work to aid safety?

PBL

[Dani]

PBL, I understand your fine irony, but finally you showed some emotion and they lead you on the correct way:

You as a specialist should ask *yourself* exactly that question you asked me:.

• Recommendations how to detect such errors
• How to overcome such problems
• Corrective actions in training, cockpit design, CRM
  aso

But, please!!!, stop all this endless reasoning about the causes, may it be primary, secondary, contributing, fitting a criterion or not.

Dani

[GlueBall]

There's space to extend the overrun by 500' across the road by building up the end zone and constructing a tunnel for the vehicular traffic. Additioanlly, the frangible rocks arresting system [already operationally proven at JFK] could be included in the extension.

[PBL]

Originally Posted by Dani

* Recommendations how to detect such errors
* How to overcome such problems
* Corrective actions in training, cockpit design, CRM
aso

Sorry, that won't do. You're copping out with that "aso". If you look at ICAO-standard accident reports, none of them have "and so on" at the end.

You are also not going to be much help if you concentrate just on trying to get the pilots to not make that kind of error. For the best pilots in the world will screw up royally two or three times in their career, and flight safety means providing an environment which doesn't let those occasions develop into broken metal and broken bones.

You will find getting rid of that "and so on" a little harder than you think. That is why no one really concerned with learning from this accident will

Originally Posted by Dani

...... stop all this endless reasoning about the causes .......

at the moment, or indeed anytime soon.

(I might say that I find your idea of emotions a bit odd!)

PBL

[TopBunk]

PBL

You can wrap it up any way that you wish, and yes there will be lessons learnt that will feed back into:

• manufacturers design considerations,
• airport operators/federal bodies requirements,
• operators/manufacturers limitations/operating procedures and indeed into
• recurrent training and information dissemination requirements

but at the end of the day, whatever we do to try to stop another accident like this happening in future, which is what we need now to do, in my view it is becoming indisputable that the first/primary/root cause of the problem in getting the aircraft stopped on the paved surface was the failure to reduce the forward thrust by the inaction of the crew to retard the thrust levers, which everyone surely must agree is learnt in basic training?

FI: on my fleet we are just completing recurrent training involving late go-arounds / balked landings (before reverse selection) / etc - and very rewarding it was too.

[PBL]

Originally Posted by TopBunk

in my view it is becoming indisputable that the first/primary/root cause of the problem in getting the aircraft stopped on the paved surface was ....

TopBunk,

if you would respond to my questions about how you prioritise causes, I might be able to agree with you (or not).

But until you say how you prioritise causes, and can demonstrate conclusively to people that your characterisation follows from your criterion, I can propose from experience that there is not the slightest hope that your suggestion will become "indisputable" any time soon.

I can even guess who can and very likely will dispute it in public. TAM's insurance company.

PBL

[slip and turn]

Originally Posted by TopBunk

...becoming indisputable that the first/primary/root cause of the problem in getting the aircraft stopped on the paved surface was the failure to reduce the forward thrust by the inaction of the crew to retard the thrust levers, which everyone surely must agree is learnt in basic training?

... I for one don't agree. I do conclude that had the engine management, aircraft braking and ground spoiler logic all received and correctly processed a signal indicating thrust had been retarded to idle on engine 2 that the first/primary/root cause most probably would have been removed from the chain of events.

I would agree that actions like

FI: on my fleet we are just completing recurrent training involving late go-arounds / balked landings (before reverse selection) / etc - and very rewarding it was too.

should be mandatory as operations and investigation continue.

[marciovp]

Steel Net

I understand they are planning to build a steel net in both ends of the runway in Congonhas. Also soft cement as a escape.

[NigelOnDraft]

flyer145 / Lemurian /

What Lemurian said is quite correct. The autobrake was not providing the decleration that was set/required! You are also correct that the autobrake could have been working but because of a slippery runway could not provide the required deceleration. However the "NO DECEL" is a standard call and was missed out! Maybe the announcement of "No spoilers" & "No decel" would have woken the PF to the real reason or prompted him to go-around.

I trust the criticisms you make of deceased pilots is made from 100% knowing this call is a TAM SOP requirement

That call is NOT an SOP in BA for instance...

[lomapaseo]

if you would respond to my questions about how you prioritise causes, I might be able to agree with you (or not).

But until you say how you prioritise causes, and can demonstrate conclusively to people that your characterisation follows from your criterion, I can propose from experience that there is not the slightest hope that your suggestion will become "indisputable" any time soon.

PBL

I support this provocation to all the posters. Unless and until those proposing blame and/or corrective action for this accident address your issues above, This thread will stay endlessly mired in speculative issues.

I can even guess who can and very likely will dispute it in public. TAM's insurance company.

PBL

on this last point, the insurance carrier really doesn't have much to say other than to argue among themselves as members of consortiums carrying the insurance for all potential parties. In the end they will simply apportion percentages of the final setllements of all claims.

[ChristiaanJ]

I understand they are planning to build a steel net in both ends of the runway in Congonhas. Also soft cement as a escape.

Ah yes. And install arrester wires, like on an aircraft carrier, and require all aircraft landing at Congonhas to be equipped with an arrester hook.

Maybe Congonhas could get their runway grooved?
And maybe the airlines flying into CGH could get their procedures sorted out?
And maybe there should be far more stringent restrictions on operation with one TR locked out?

Arrester barriers are for the military.

[NigelOnDraft]

CJ

And maybe there should be far more stringent restrictions on operation with one TR locked out?

I'd agree with your post apart from this bit... It has been extensively discussed above that 1 T/R U/S has little effect on LDR, especially if you ignore contaminated runways - and then they are duly allowed for if required. Whilst the T/R Inop seems likely to be implicated @ CGH, it is as a side effect, not a performance issue...

As you say, the EMAS / barriers / overruns might help with the previous minor excursions. The TAM aircraft left the runway at nearly 100K

[BOAC]

I have again to take issue over the general question of reverser effectiveness. It seems that the 320 requires an increase of only 55m in LDR for all runway conditions according to the TAM MEL. I must therefore assume that the 320 reversers are almost ineffective. The Boeing 737-700 requires an additional 370m for braking action 'Poor' with 1 u/s and 970m for both, which is far from 'little effect'.

[ChristiaanJ]

Nigel,
I've read most of the 1900+ posts.
Shoot me down any time, but the way I read it all, it is as simple as this.

One TR locked out... rather unusual, but they have flown with that before.
Now, short, slippery runway.... oh sh!t.
What's the SOP about one TR inop? We won't get the same decel with one TR!
Oh, don't pull that engine into reverse, then.

.....

And somehow, instead of doing what should be ingrained: slamming both TLs to reverse, never mind if one TR is inop, they don't touch the #2 TL.

The rest is a sad history.

[NigelOnDraft]

BOAC... I think you are either misunderstanding something, or using differently based data

BA QRH A320 IAE 2 Rev Operative, Max Manual Braking, improves LDR from 50' by 5% (Dry) to 24% Ice over no Rev.

NB there might still be issues between a 1980s modern certification rules aircraft, and a 1960s retread hiding under some Grandfather rules

[bomarc]

christian j

<< And somehow, instead of doing what should be ingrained: slamming both TLs to reverse, never mind if one TR is inop, they don't touch the #2 TL.>>

did you mean slamming to idle? reverse woud have been icing on the cake.

[NigelOnDraft]

CJ... Sorry - don't 100% understand your post...

What's the SOP about one TR inop? We won't get the same decel with one TR!
Oh, don't pull that engine into reverse, then.

That was the old MEL... hardly affects LDR. However, seems an "HF issue" meant that maybe this crew, and others, were led into not even selecting idle in this engine, and leaving it not far off Climb Power

Reason for the MEL advice was to avoid the "locked out" Eng slightly increasing Fwd Thrust as engine went to "Rev Idle" EPR / RPM - a little higher than "Ground Idle".

And somehow, instead of doing what should be ingrained: slamming both TLs to reverse, never mind if one TR is inop

The new MEL, and unfortunately the change was prior CGH, but maybe too late in distribution / publication / understanding

The rest is a sad history.

It is, but nothing to do with "1 Rev U/S" performance IMHO. It seems an HF issue, now corrected I think...

[PAXboy]

marciovp

I understand they are planning to build a steel net in both ends of the runway in Congonhas. Also soft cement as a escape.

Are the politicians still saying that they will find a new site for a new airport 'within 90 days', as they did within a week of the crash?

BOAC

It seems that the 320 requires an increase of only 55m in LDR for all runway conditions according to the TAM MEL. I must therefore assume that the 320 reversers are almost ineffective. The Boeing 737-700 requires an additional 370m for braking action 'Poor' with 1 u/s and 970m for both, which is far from 'little effect'.

(non pilot speaking) I wonder if that is based on 'idle reverse'?? I often see reference to that, as opposed to some level of increased thrust for reverse. It is possible that Airbus designed reverse to be used at idle, so as to keep noise levels down, something that has always been a key factor for them. Just a thought.