TAM A320 crash at Congonhas, Brazil

[DozyWannabe]

SIDSTAR:
Just to clarify the AI position: Airbus changed the method of dealing with a locked out reverser last year but gave no reason for the change. Perhaps it was linked to the previous incidents?

In all likelihood, if the human factors reports on those incidents suggested that some pilots had a tendency to filter the information "both to idle, then one reverse" in such a way that only one lever was pulled back in some circumstances, then I expect it was down to that.

[PBL]

Originally Posted by gpvictor

I wonder why Airbus did maintain a somewhat complicated landing procedure with one locked reverse ......... a change in the software i.o. to unify all landing procedures, with or w/out reverse, should be implemented.

gpvictor,

you are likely new to this thread. This, and a number of related issues, have been extensively discussed already. I know this doesn't necessarily help much, given 2000+ posts, but it would explain why many will not rush to answer you.

PBL

[FlightDetent]

SIDSTAR:
Just to clarify the AI position: Airbus changed the method of dealing with a locked out reverser last year but gave no reason for the change. Perhaps it was linked to the previous incidents?

Originally Posted by DozyWannabe

In all likelihood, if the human factors reports on those incidents suggested that some pilots had a tendency to filter the information "both to idle, then one reverse" in such a way that only one lever was pulled back in some circumstances, then I expect it was down to that.

I believe it is related to the Irkutsk S7 accident where most probably fingertrouble led to increasing thrust on one engine when reverse was being deselected on the other.

[RWA]

Originally Posted by bsieker

You'll notice that he uses the same grip to get from reverse back to forward idle (going a bit past and pushing firmly back to idle stop, as other pilots said is normal.)

Quite correct, bsieker - maybe, as you imply, it's just that particular pilot's 'patent' grip. Possibly he uses it to make sure he keeps the movement of both handles exactly even, rather than the 'twist of the wrist' that most pilots use. But looking at the video again, another point occurred to me that I don't think has previously been discussed; the question of the reverser latches.

As far as I know the A320 is unique among Boeing/Airbus designs in having the same levers do duty both as throttles and reverser levers. Boeing have completely-separate reverser levers, other Airbus marques have reverser levers built in to the top of the main throttle levers; but these are also separate. As far as I know, in all the separate lever types, the reverser levers won't move at all unless both (or all four) throttles are at idle.

With the A320 approach, there also has to be a safety-catch arrangement preventing the accidental movement of one or both of the 'dual-purpose' levers into the reverse position in the wrong circumstances. On researching this I found that this takes the form of safety-latches in front of, and at the base of, each lever; which have to be lifted before the levers can be moved into the 'reverse thrust' section of the throttle quadrant.

Looking again at the Madeira video oner can clearly see that that pilot, in order to lift the latches, had to reach quite far over the handles, with his fingers extended and his wrist possibly resting on the top of the handles.

Seems to me that this arrangement (unique to the A320, as far as I know) could, in a situation where the pilot was intent on selecting reverse on one engine only, materially increase the risk of the OTHER handle being accidentally knocked, if not right up to the CLB detent, at least out of the 'Idle' detent?

Hunitng round for a picture of the A320 throttle setup I chanced on this article. It does indeed provide a picture of the console (from which you can see how far 'over' the throttle handles the reverser-latches are) but i discover that it also provides quite a lot of analysis of the Congonhas accident and also discusses several other 'one-reverser-inop.' accidents, all but one involving A320s, in which the same 'misplaced lever on inop. side' cause was found to have been to blame.

http://www.airaccidentdigest.com/0807_story3.php

[marciovp]

Aero Magazine

The last issue of Aeromagazine is out. www.aeromagazine.com.br

It mentions the TAM accident two times.

1. One saying that AB sent a note (AIT 4) with considerations about Flight 3054 from TAM saying that there were nothing abnormal about the plane. But now some information in the AIT 4 are being contested by pilots and security especialists. AB states that "manual actions for plain breaking started 11 seconds after touchdown". However analysis of FDR show that the pilots applied maximum breaking only 5 seconds after touching down. In the final text of the AIT 4 they say that " the data of the recordings DFDR and CVR don´t show evidence of malfunction in the airplane". But sources cinnected to the investigation said that the information only refers to the state of the black boxes of the airplane and not to all systems.

2.The TLs. There is a enigma of the TLs of autothrust. According to FDR the right motor had the reverser blocked and presented a peak of potency seconds before touch down and after that deccelerates a little but remained accelerating while the reverser of the left motor was applied. However the TL of the right motor was not in the Climb position and instead was half the way betwenn Idle and Climb (22.5 degrees). The suspition problems with the software were at work became more important after the pilot Marco Aurelio Incerti from TAM who piloted the plane on the day of the accident said that he did not follow the recommendation of AB for landing with one reverse locked out. He said that when he landed he went into reverse with motor 1 and he left the TL on motor 2 on Idle. CENIPA os also investigating a voice in the cockpit that was not in the transcript saying that the "TL doesn´t move, it is jammed".

[bsieker]

On Reverse Levers

(Boeing uses reverse levers on top of the normal thrust levers, at least in the B737NG, as does Airbus in the A340, from what I can see.)

Originally Posted by RWA

As far as I know, in all the separate lever types, the reverser levers won't move at all unless both (or all four) throttles are at idle.

This has been falsified, at least for the B747-400, by the Tahiti overrun, which has been mentioned in this thread.

The FDR graphs clearly show engine #1 "escaping" to around 106% N1 (probably at or near go-around thrust), and afterwards the other three engines being put into reverse. So there is no cross-lever interlock, despite what some people here seem to have inferred from the FCOM.

Seems to me that this arrangement (unique to the A320, as far as I know) could, in a situation where the pilot was intent on selecting reverse on one engine only, materially increase the risk of the OTHER handle being accidentally knocked, if not right up to the CLB detent, at least out of the 'Idle' detent?

Perhaps. But this is speculative.

It is also irrelevant.

The FDR graphs show that the #2 thrust lever was not "knocked up" after being pulled down, but stayed untouched, in the CL detent (if we take FDR reading to be the actual TL position).


Bernd

[bsieker]

marciovp, thanks for the translation,

Originally Posted by marciovp, translating from aeromagazine.com.br

However the TL of the right motor was not in the Climb position and instead was half the way betwenn Idle and Climb (22.5 degrees).

Another one of those "experts" at work here.

According to the FDR graphs, the #2 thrust lever was left at the position where it had been, and at the same angle where #1 thrust lever also was, until that was retarded. This is crystal clear in the graphs.

22.5 degrees is halfway of the total forward TL movement. But not halfway to CL, but halfway to TOGA. And at that position happens to be the CL detent.


Bernd

[atakacs]

CENIPA os also investigating a voice in the cockpit that was not in the transcript saying that the "TL doesn´t move, it is jammed".

They must be kidding !

[flyingnewbie10]

CENIPA was also investigating a voice in the cockpit that was not in the transcript saying that the "TL doesn´t move, it is jammed".

Despite being myself someone who is asking for some investigation on the possibility of an electronical/mechanical failure I have to admit that the article has a lot of misinformation (autothrust levers ?).

Maybe someone really said something about a jammed TL but the source does not seem to be that credible.

[Lemurian]

of rudder and brakes

Back again into the fray ! (Some have to fly for a living, you know !)
Referring to my #20954 post :

The only conclusion is that these instances indicate attempts -successful - at using differential braking for directional control, which seems to confirm the slipperiness of the runway (I still haven't given-up on the presence of aquaplaning ).
At 100+ knots the rudder would still have significant influence on directional control, I assume?

But that's exactly the point, Bernd : They shouldn't have needed differential braking for directional control. Unfortunately, due to the tools I have here, I cannot really cerrelate with any acceptable accuracy the lateral acceleration with the brakes and rudder inputs. I think we could dismiss the accidental brake application on rudder pedal movement as the then pilot flying was quite able to do so on most of the brake pressure graph.

Seems to me that this arrangement (unique to the A320, as far as I know) could, in a situation where the pilot was intent on selecting reverse on one engine only, materially increase the risk of the OTHER handle being accidentally knocked, if not right up to the CLB detent, at least out of the 'Idle' detent?

That's what I call clutching at straws :The design is such that the hand just goes over the T/Ls handfles -I'm not very big,but I manage quite easily to keep the ball of my thumb on the top of the throttles, reaching with two fingers only for the latches ; in this way my hand is in the ideal position for pulling the T/Ls into the reverse range.
Why wasn't this set-up kept for the twin-engined A330 ? Just for commonality with the A340. That airplane having four throttles makes the latch solution impractically ackward, unless one has six fingers.
Had you read the Camair incident mentioned four pages earlier, you would have found that the risk of moving accidentally the throttles was achieved by that particular 747 crew.
marciovp,
Thanks for your translations and your honesty in letting us know about the technical knowledge of Airbus systems by bloggers and journalists in your country. Rest assured that they exist also in every country I know. So please stop citing articles on subjects we dealt with on this thread a few hundred posts ago. Please ?

[marciovp]

OK

Thanks for your translations and your honesty in letting us know about the technical knowledge of Airbus systems by bloggers and journalists in your country. Rest assured that they exist also in every country I know. So please stop citing articles on subjects we dealt with on this thread a few hundred posts ago. Please ?

OK Lemurian, I thought it would be of some interest to bring to this thread what appears in Brazil press and especialized magazines (Aero). If this is not being helpful or of some interest, of course ,I will oblige and try to stop waisting the time of people here. Many regards.

[flyingnewbie10]

So please stop citing articles on subjects we dealt with on this thread a few hundred posts ago. Please ?

C'est le Roi des Lemurians qui est arrivé...
Et Il ne peut pas etre conteste...
Donc S'il vous plait,
Arretez de l'importuner, MarcosVP

(Apologies. French from elementary school...)

[Dani]

AI is not the only manufactor using TL as revers levers. All turboprops I know come into my mind (and don't tell me that on turboprops the reverser is less essential than in a medium jet). These levers in between the TL are very common. I remember that there were always pilots having problem with it, but to try first, you have to pull both into idle, which the TAM pilot obviously never tried.

Dani

[flyingnewbie10]

you have to pull both into idle, which the TAM pilot obviously never tried.

Obviously you admit you could make the same mistake in a similar situation.

[RWA]

Originally Posted by bieseker

This has been falsified, at least for the B747-400, by the Tahiti overrun, which has been mentioned in this thread.

Since, as far as I can make out, that was a no-injuries 'incident' back in 1993, bieseker, I'm not surprised that I can't google up any sort of comprehensive report on it. Were there any identified 'causes' of it that are relevant to the CGH crash?

Originally Posted by bieseker

Perhaps. But this is speculative.

I thought we were all speculating? I hope I've made my own position clear. There isn't much difference between any of us as to WHAT happened; the 80% probability is that a pilot with over 10,000 hours made a dumb mistake, failed to bring a throttle lever back to 'idle' before landing. Contrary to the drill that is drummed into everyone who has ever flown anything before they're even allowed to solo.

I'm much more concerned with the question of WHY he made such a huge mistake. Only if the 'why' is established ('beyond reasonable doubt,' anyway) can the authorities and the manufacturer take steps to prevent the same thing happening again. It's certainly not enough just to 'prove' that it was pilot error; especially since there have been several recent exactly-similar 'errors' involving highly-experienced pilots landing A320s with one reverser inoperative, and few if any recent ones with other marques?

Originally Posted by Lemurian

That's what I call clutching at straws

Wasn't aware that I was in danger of drowning, Lemurian?

Originally Posted by Lemurian

The design is such that the hand just goes over the T/Ls handfles -I'm not very big,but I manage quite easily to keep the ball of my thumb on the top of the throttles, reaching with two fingers only for the latches ; in this way my hand is in the ideal position for pulling the T/Ls into the reverse range.

Thanks for the first-hand information. Have you ever had to operate the levers as laid down in the previous MEL, 'one to idle, one to full reverse'? Or opted to, or been asked to, practise the drill on a simulator? If so, how did you get on? Any snags or difficulties?

[sky9]

Many years ago we had a spate of cabin staff opening the doors with the slides armed. The initial management response was to put out a notice saying that the next cabin staff to do it would be fired.
It was pointed out to the management that one slide activation could be an error, a regular occurrence would indicate that the procedure was wrong.
The procedure was changed and no more slides were deployed.
Now about the 320 thrust levers ......

[IFixPlanes]

Now about the 320 thrust levers ......
If the Crew follow the SOP the TL is in idle.
IMHO no change required

[bsieker]

I thought we were all speculating?

Of course we are.

I'm much more concerned with the question of WHY he made such a huge mistake. Only if the 'why' is established ('beyond reasonable doubt,' anyway) can the authorities and the manufacturer take steps to prevent the same thing happening again. It's certainly not enough just to 'prove' that it was pilot error; especially since there have been several recent exactly-similar 'errors' involving highly-experienced pilots landing A320s with one reverser inoperative, and few if any recent ones with other marques?

I agree.

But since the persons directly involved in the handling of the thrust levers in this accident cannot be asked any more, I don't think we will ever reach the "beyond reasonable doubt"-state. So a "reasonably credible explanation" will have to do. And if there is more than one, perhaps more than one thing should be fixed. Accident investigation reports usually contain many recommendations, which may or may not be made mandatory by the authorities.

The reason I dismissed this particular speculation was not that it was speculative, but that it was obviously not what happened here. TL#2 reading was and stayed in CL undisturbed.


Bernd

[PBL]

Originally Posted by aeromagazine, cited by marciovp

However analysis of FDR show that the pilots applied maximum breaking only 5 seconds after touching down.

This is complete rubbish.

Originally Posted by aeromagazine, cited by marciovp

However the TL of the right motor was not in the Climb position and instead was half the way betwenn Idle and Climb (22.5 degrees).

Also complete rubbish, as bsieker has pointed out.

Originally Posted by aeromagazine, cited by marciovp

The suspition problems with the software were at work became more important after the pilot Marco Aurelio Incerti from TAM who piloted the plane on the day of the accident said that he did not follow the recommendation of AB for landing with one reverse locked out. He said that when he landed he went into reverse with motor 1 and he left the TL on motor 2 on Idle.

And even here they manage to screw it up. What have different procedures for handling REV INOP have to do with software?

David Evans did raise a point in his article on the crash, cited by RWA, which I have not yet seen on this thread. David pointed out that the apparently different ways of handling thrust reduction with REV INOP on the two flights previous to the crash demonstrates a training issue at TAM.

In contrast to others, I appreciate marciovp citing a specialist magazine in Brazil which is publishing nonsense. For those concerned with propagating correct information and analyses, it is good to know what is "out there". But it is not as if we are entirely without our own. People who think that the only cause (read "causal factor") was the pilot failing to reduce thrust to idle might do well to read the first few inches of column space of David's article, in which he discusses the runway situation at Congonhas.

PBL

[Lemurian]

RWA

Have you ever had to operate the levers as laid down in the previous MEL, 'one to idle, one to full reverse'? Or opted to, or been asked to, practise the drill on a simulator? If so, how did you get on? Any snags or difficulties?

Yes, I have, both on the sim and in real line operations. There is no problem at all, both on reverse selection and on directional control, even on a wet runway.(Mind you, never in the short / slippery surface that was CGH runway at the time of the accident ).
As a matter of fact, flying for an airline that completes some 1100 /1200 landings per day on the 320 family, I have never heard of any such mis-manipulation of the T/Ls.
flyingnewbie

C'est le Roi des Lemurians qui est arrivé...
Et Il ne peut pas etre conteste...
Donc S'il vous plait,
Arrete de l'importuner, MarcosVP

Your french is pretty good. just add a *z* to "arrete" to get the polite form of verb address and it would be perfect.
Regarding marciovp's citations, and here I disagree with PBL, it is not a matter of contestation, it's the fact that obviously this accident has a lot of political implications which are polluting both the families' privacy and right to mourn their losses serenely and this thread which should remain as objective as possible.
I was -and still am - rather concerned about the publication of the CVR transcript, although it has been quite severely edited as the last moments of the crew -therefore of all the people inside this airplane- became fodder for the public's - often ghoulish - curiosity and scrutiny.