TAM A320 crash at Congonhas, Brazil
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atakacs,
Yes, I agree that there are three incidents (amongst them two hull losses) which have significant similarity:
* 1998 Bacolod (BTW, I found the report, and in this incident #1 TL was left in the CLB position. However, the report does not address the question why the crew did not appear to use "manual" brakes as per SOP. It also doesn't say whether #1 reverser was known INOP or not.)
* 2004 Taipei-Sungshan
* As far as it appears, 2007 Congonhas
The question of prophylaxis appears to me most easily addressed by asking what can get *all* crews, without exception, to reduce both thrust levers to idle on touchdown, or shortly thereafter; and to use manual brakes immediately if the commanded deceleration is not confirmed.
It may be that other issues will arise from the analysis, but, as has been noted, these are the two big issues so far, so they will be addressed in any case.
I will guess that, if it is found that the TAM aircraft did not incorporate the SB arising from the Taipei incident, the measure taken will be to turn this SB into an AD.
PBL
two accidents seem to have much in common. And having 3-4 hull loses out of 14(18?) due to very similar circumstances is significant IMHO...
* 1998 Bacolod (BTW, I found the report, and in this incident #1 TL was left in the CLB position. However, the report does not address the question why the crew did not appear to use "manual" brakes as per SOP. It also doesn't say whether #1 reverser was known INOP or not.)
* 2004 Taipei-Sungshan
* As far as it appears, 2007 Congonhas
The question of prophylaxis appears to me most easily addressed by asking what can get *all* crews, without exception, to reduce both thrust levers to idle on touchdown, or shortly thereafter; and to use manual brakes immediately if the commanded deceleration is not confirmed.
It may be that other issues will arise from the analysis, but, as has been noted, these are the two big issues so far, so they will be addressed in any case.
I will guess that, if it is found that the TAM aircraft did not incorporate the SB arising from the Taipei incident, the measure taken will be to turn this SB into an AD.
PBL
Last edited by PBL; 6th Aug 2007 at 19:02. Reason: Taipei-Sungshan was not a hull loss!
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PBL, you're not a pilot either, very hard to discuss this with non pilots.
Personally I've already learned a great deal from this thread, found many new sources of information, and been presented with many new considerations about how things are and why from posters like PBL, PJ2 and bsieker, among others. Simply reading and thinking critically about what is passed back and forth here is an exercise in safety education that can benefit everyone in the industry and in so doing fulfill one of the site's founding purposes.
How about we don't diminish that with below the belt shots, especially ones aimed at someone who is bringing a truly valuable perspective to the table?
Deal?
ELAC
Last edited by ELAC; 6th Aug 2007 at 19:00.
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Originally Posted by discountinvestigator
[...] If you want to look at equipment failure, then be very careful about the difference between actual position and recorded position data on the FDR. Do they have dual channel readouts? Was there a failure of one thrust lever sensor channel which was unrevealled but occurred earlier in the flight with a second (or logic elimination of its reading) later at RETARD?
In short: dual sensors, a failure of one sensor is not hidden, but FADEC reverts to failsafe settings. typically TOGA or FLX during takeoff, idle on the ground or with slats extended, MCT otherwise.
So the FDR readout will most likely reflect actual thrust lever setting, although I'm certain the investigation will look into the possibility of an undetected fault here, too.
Last edited by bsieker; 6th Aug 2007 at 19:22.
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Dream Land
You might have had the courtesy to visit PBL's homepage before your uncalled-for remark - as you describe yourself as a "bus driver" the same could have been said of you.
TP
You might have had the courtesy to visit PBL's homepage before your uncalled-for remark - as you describe yourself as a "bus driver" the same could have been said of you.
TP
discountinvestigator;
Understand and appreciate the disagreement. I wonder however, if it is possible to design a system which is capable of achieving a zero-error rate? As has been established here, notwithstanding the four accidents acknowledged as similar (not to mention similar historical records for both types), what must be borne in mind is the 50-million (or so) other Airbus landings where such misapprehensions regarding the autothrust system did not result in an incident or accident.
That is truly a remarkable achievement in and of itself, a fact which, while it may do nothing to diminish the tragedy of this accident, is a reassuring notion which demands perspective at least in terms of setting one's hair on fire at the slightest scent of heretical observations, (which have, I understand, perhaps very occasionally occurred here from time to time...)
A thousand posts or so ago, I mentioned the medical profession, ...would that they could achieve the remarkable safety record enjoyed by our industry, and that the iatrogenic (medical/hospital) death rate applied to our industry would be spectacular and the US yearly death rate by cars alone is a full jumbo transport (350 passengers) going in every third day of the year....
Such statistics (and they are not insignificant) would put us [deservedly] out of business in a heartbeat, yet for some reason, accountability, let alone visibility in these two clearly-high-risk societal institutions, is not addressed to nearly the same degree as it is in aviation.
Flight data programs literally invade our workplace from start-to-finish and we as professional airmen accept such massive intrusions into our cockpits as our contribution (not our only one, either) to the advancement of flight safety.
Apologies for the thread diversion; DFDR discussions including dialogue on sample rates, parameter availabilities, FDA/FOQA Programs at TAM etc, may soon become an important part of this thread as the DFDR information becomes available.
Understand and appreciate the disagreement. I wonder however, if it is possible to design a system which is capable of achieving a zero-error rate? As has been established here, notwithstanding the four accidents acknowledged as similar (not to mention similar historical records for both types), what must be borne in mind is the 50-million (or so) other Airbus landings where such misapprehensions regarding the autothrust system did not result in an incident or accident.
That is truly a remarkable achievement in and of itself, a fact which, while it may do nothing to diminish the tragedy of this accident, is a reassuring notion which demands perspective at least in terms of setting one's hair on fire at the slightest scent of heretical observations, (which have, I understand, perhaps very occasionally occurred here from time to time...)
A thousand posts or so ago, I mentioned the medical profession, ...would that they could achieve the remarkable safety record enjoyed by our industry, and that the iatrogenic (medical/hospital) death rate applied to our industry would be spectacular and the US yearly death rate by cars alone is a full jumbo transport (350 passengers) going in every third day of the year....
Such statistics (and they are not insignificant) would put us [deservedly] out of business in a heartbeat, yet for some reason, accountability, let alone visibility in these two clearly-high-risk societal institutions, is not addressed to nearly the same degree as it is in aviation.
Flight data programs literally invade our workplace from start-to-finish and we as professional airmen accept such massive intrusions into our cockpits as our contribution (not our only one, either) to the advancement of flight safety.
Apologies for the thread diversion; DFDR discussions including dialogue on sample rates, parameter availabilities, FDA/FOQA Programs at TAM etc, may soon become an important part of this thread as the DFDR information becomes available.
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ELAC:
one engine is being reversed with the plane on the ground command the other one to idle if its not doing the very same + uncommanded reverser deployment after V1 on takeoff = YOU'RE DEAD!
It's not as easy as it might seem to define the correct logic for situations such as this.
It's not as easy as it might seem to define the correct logic for situations such as this.
Notice that when thrust lever is left in CLB detent during ATHR disconnect, the power will NOT start to rise towards climb power, it stays at the last ATHR commanded power UNTIL the pilot moves the lever. From that point onward, the computer will again consider the lever to be reflecting pilots intentions. Until s/he moves it, it assumes it was forgotten there.
The computer already ACTS based on the assumption that L2 lever was unintentionally left in CLB detent. It just isn't consistent in ingnoring the physical lever position. It ignores its position regarding the thrust but it does not ignore it regarding the logic that prevents spoilers to deploy. That kind of dischord should not be there.
IF it was consistent with the logic of ignoring the lever position, but would again start to act based on its position after pilot moves it (to TOGA for example), then it would NOT kill you in any other scenario. You could still command the plane to do whatever you want. And you'd still get the spoilers and autobrakes after selecting one reverse (which cuts ATHR off).
So. My revised list of what I would think AB engineers should change:
1. continue "Retard" calls while at least one lever above idle and brakes and/or reversers on.
2. warn about the same on ECAM
(i.e. changes that are already implemented in newer software)
and 3: ignore the thrust lever position in all decision-making while it's position is being ignored for thrust determination because it was left in CLB detent during ATHR disconnect.
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bsieker says:
I suspect (but have no specific knowledge of the A320) that the FDR will show both sensors on each TL, along with the resulting FADEC response.
So the FDR readout will most likely reflect actual thrust lever setting, although I'm certain the investigation will look into the possibility of an undetected fault here, too.
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PBL, you're not a pilot either, very hard to discuss this with non pilots.
PBL, I think you did fine.
that is, if no braking, you go around
Dreamland, may I quote yourself:
I think you are well meaning but let's hope that you aren't employed as a professional pilot. 
without spoilers, there is no braking
Yes, it takes a 40% - 50% longer distance, too much for SBSP (CGH), but for sure braking action is more than "nothing".
What I really like is to "accuse" somebody (is this really something you can be accused for?) of being a non-pro and to reveal lack of knowledge shortly after. SCNR
----------------
Somebody asked whether 'Airbus' reads public threads like this one.
I think, there is too much chaff and too little wheat in it, especially from people who know very little about the systems of the aircraft. That is not meant to be negative *), but Airbus' safety department is not interested in "my plane is better than yours" and has much more reliable sources. Customer service department has first hand reports from almost every single incident which never made it into the news, including PIREPS from the ones who were involved (in real life, that is). (By the way, Airbus and Boeing et al. do not compete on safety critical items. Instead, there is knowledge exchange on certain topics behind all the marketing theaters' curtains. You can take that as a fact.)
*) Since I did it myself - reading all the stuff here.
May I quote ELAC in order to express that for me:
Personally I've already learned a great deal from this thread
barit1, (quoting bsieker):
It depends upon the dataframe in use. While there is far greater standardization among DFDRs than QARs (typical of FDA/FOQA installations), some recorders are programmed or otherwise limited to as few as 600 parameters, near the legal minimum, whereas others may provide upwards of 2000 parameters. I am told that the C17 provides upwards of 30,000 parameters, just for comparison.
Also, there may be different sample rates, varying from once per second to eight times per second. It depends upon the installation...ie, storage capacity, programming and the country's regulator requirements.
In such circumstances, the one-second recording rate for some critical parameters can be exceedingly limiting although experience can help. In the same way a strobe light illuminates disco-dancers in an-otherwise completely dark room, it is always a risky venture to merely "interpolate" what happened in the intervening darkness (time) period between flashes.... An ideal recording rate might be approximated by either video or film rates of around 26 to 32 fps's but then processor, memory and storage issues arise even with wireless or satellite download solutions.
Among the many parameters we'll see (all likely one-second sample rates), are the left and right TLA (thrust lever angle) parameters as well as the standard engine parameters (essentially, engine responses to FADEC commands), but we may not see very many parameters from the FADEC itself.
Again, apologize for thread-creep...
(bsieker): So the FDR readout will most likely reflect actual thrust lever setting, although I'm certain the investigation will look into the possibility of an undetected fault here, too.
barit1 in response:
I suspect (but have no specific knowledge of the A320) that the FDR will show both sensors on each TL, along with the resulting FADEC response.
I suspect (but have no specific knowledge of the A320) that the FDR will show both sensors on each TL, along with the resulting FADEC response.
Also, there may be different sample rates, varying from once per second to eight times per second. It depends upon the installation...ie, storage capacity, programming and the country's regulator requirements.
In such circumstances, the one-second recording rate for some critical parameters can be exceedingly limiting although experience can help. In the same way a strobe light illuminates disco-dancers in an-otherwise completely dark room, it is always a risky venture to merely "interpolate" what happened in the intervening darkness (time) period between flashes.... An ideal recording rate might be approximated by either video or film rates of around 26 to 32 fps's but then processor, memory and storage issues arise even with wireless or satellite download solutions.
Among the many parameters we'll see (all likely one-second sample rates), are the left and right TLA (thrust lever angle) parameters as well as the standard engine parameters (essentially, engine responses to FADEC commands), but we may not see very many parameters from the FADEC itself.
Again, apologize for thread-creep...
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11 seconds seems a long time to not initiate manual braking. I fly a 737 classic into shorter runways than that and whilst using autobrake I will almost always 'follow through' on the brakes manually and if it doesn't seem enough then my pressure will trip out the autobrakes and give more manual braking. I wouldn't necessarily notice if the spoilers didn't deploy - its the nhp's job to monitor that.
There would be a large stagger between the thrust levers on a 737 which would be very noticable if you didn't close one - and don't forget reverse is a different lever attached to the top of the forward thrust lever, so even with one locked out the levers will both be in the same position at idle, but one will have the reverser lever up, one won't - it would be wire tied.
Also, in some airlines that fly monitored approaches the Non handling pilot selects reverse whilst the handling pilot initiates / monitors braking.
There would be a large stagger between the thrust levers on a 737 which would be very noticable if you didn't close one - and don't forget reverse is a different lever attached to the top of the forward thrust lever, so even with one locked out the levers will both be in the same position at idle, but one will have the reverser lever up, one won't - it would be wire tied.
Also, in some airlines that fly monitored approaches the Non handling pilot selects reverse whilst the handling pilot initiates / monitors braking.
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on the airbus 320, is there a mechanical sort of sound indicating the spoilers are deploying? even a synthetic sound would help.
on my favorite jet, the sound of the spoiler handle moving is a big part of landing.
on my favorite jet, the sound of the spoiler handle moving is a big part of landing.
bomarc;
I know what you mean in terms of sound...one becomes accustomed to the motor that drives the lever back. (On the DC8, (40-series), it was actually the nosewheel oleo compression that mechanically drove the lever back - later series didn't wait until the nose was down).
No, under the familiar philosophy that only faults are annunciated, there is no sound, no movement. The indications as well as the SOPs assume that all is working as designed unless there is a fault. That is when annunications would occur and crew action, where indicated/memorized, would occur.
"No spoilers, no reverse" if the thrust levers are not at idle is not a fault in this case, it is a well-proven design. I would be surprised if any aircraft permitted such.
In Canada, we are accustomed to year-round occurrences of contaminated runways so there is a high-degree of awareness and knowledge of those things that will protect one in as many circumstances as possible when the numbers approach marginal conditions.
We have lobbied and otherwise pressed for Toronto's overrun area on the 24's since the first overrun in 1978 and even now, two years after AF358, there is no change.
PJ2
I know what you mean in terms of sound...one becomes accustomed to the motor that drives the lever back. (On the DC8, (40-series), it was actually the nosewheel oleo compression that mechanically drove the lever back - later series didn't wait until the nose was down).
No, under the familiar philosophy that only faults are annunciated, there is no sound, no movement. The indications as well as the SOPs assume that all is working as designed unless there is a fault. That is when annunications would occur and crew action, where indicated/memorized, would occur.
"No spoilers, no reverse" if the thrust levers are not at idle is not a fault in this case, it is a well-proven design. I would be surprised if any aircraft permitted such.
In Canada, we are accustomed to year-round occurrences of contaminated runways so there is a high-degree of awareness and knowledge of those things that will protect one in as many circumstances as possible when the numbers approach marginal conditions.
We have lobbied and otherwise pressed for Toronto's overrun area on the 24's since the first overrun in 1978 and even now, two years after AF358, there is no change.
PJ2
SingleLensReflex;
Hm, I don't think so. Please let me say why.
There are varied opinions from interested observers who know very little about the subject (and now perhaps they know more), as well as some fine work offered by many aviation professionals.
With the exception of those who have already signaled that their minds are made up about Airbus, wet runways, Brazil's aviation infrastructure or what-have-you, for those who still suspend judgement in favour of curiosity the discussion has largely been an open one where knowledgeable people have helped understanding. Perhaps not for all, but I think for many, pain is alleviated through comprehension. Sometimes it may seem lost in the minutae of discussion, but certainly, support for family and friends lost is ever-present here.
I believe this kind of behaviour on the part of aviation people honors more than silence could, those who have tragically lost their lives. Remember, many here are crew - both front and back, are maintenance people, are passenger and baggage agents, are designers, are instructors, are aviation managers, who have an abiding and sometimes passionate need to know what happened so that they may add to their own knowledge.
I'm sorry you feel this way - I hope this helps.
It has descended to a chatter unworthy of the souls who perished.
There are varied opinions from interested observers who know very little about the subject (and now perhaps they know more), as well as some fine work offered by many aviation professionals.
With the exception of those who have already signaled that their minds are made up about Airbus, wet runways, Brazil's aviation infrastructure or what-have-you, for those who still suspend judgement in favour of curiosity the discussion has largely been an open one where knowledgeable people have helped understanding. Perhaps not for all, but I think for many, pain is alleviated through comprehension. Sometimes it may seem lost in the minutae of discussion, but certainly, support for family and friends lost is ever-present here.
I believe this kind of behaviour on the part of aviation people honors more than silence could, those who have tragically lost their lives. Remember, many here are crew - both front and back, are maintenance people, are passenger and baggage agents, are designers, are instructors, are aviation managers, who have an abiding and sometimes passionate need to know what happened so that they may add to their own knowledge.
I'm sorry you feel this way - I hope this helps.
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Originally Posted by SingleLensReflex
It has descended to a chatter unworthy of the souls who perished.
Please drop it and move on?
Please drop it and move on?
But to then throw your prima donna like fit and demand that the thread be locked, is totally out of order.
Who made you judge, jury and executioner?
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@TripleBravo
Agreed. But those of us in large organisations who don't have day-to-day contact with the ops side - and it's the ENGINEERING organisations who generally do the designing and redesigning, not the customer service guys, who we do our best to ignore 
- a discussion like this is very educational in understanding all the different ways what WE think is simple and straightforward is actually implemented by the guys (and girls) at the "pointy end". Even the "chaff" is educational - because if one of "you" doesn't understand properly how our system works it may well mean that one of "us" failed to explain it properly.
Customer service department has first hand reports from almost every single incident which never made it into the news
- a discussion like this is very educational in understanding all the different ways what WE think is simple and straightforward is actually implemented by the guys (and girls) at the "pointy end". Even the "chaff" is educational - because if one of "you" doesn't understand properly how our system works it may well mean that one of "us" failed to explain it properly.
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Great Thread
As along time lurker, non-pilot and ocational PAX. My personal opinion is that this thread has had less negativity and more professional contributions than other high profile threads over the last couple of years. This could be due to highly efficient moderators, or that I can't tell the difference between informed and uniformed comments but probably just a big dose of civility. Very refreshing. I would also like to say Thank You to PPRuNe moderators and Danny for letting curious onlookers observe a bit of another professions processes.
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Info
Info that may or not be confirmed but I read:
a) the two pilots flew from Congonhas to Porto Alegre on the same day before coming back to Congonhas.
b) both had more than 14000 hours of flying.
c) one of them flew many years (20) for Transbrasil on 767. In 2001 worked from September to December at GOL (Boeing 737). In January
2007 started at TAM and up to recently was in training for the A-320
plane. The other was with TAM since 1987.
d) TAM did not incorporate the modifications that AB suggested after the Taiwan accident. For some reazon this was not mandatory by AB. Why?
And...a question:
Why one of the pilots said that he couldnīt do it after the other asked him to decrease acceleration?
a) the two pilots flew from Congonhas to Porto Alegre on the same day before coming back to Congonhas.
b) both had more than 14000 hours of flying.
c) one of them flew many years (20) for Transbrasil on 767. In 2001 worked from September to December at GOL (Boeing 737). In January
2007 started at TAM and up to recently was in training for the A-320
plane. The other was with TAM since 1987.
d) TAM did not incorporate the modifications that AB suggested after the Taiwan accident. For some reazon this was not mandatory by AB. Why?
And...a question:
Why one of the pilots said that he couldnīt do it after the other asked him to decrease acceleration?
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Why one of the pilots said that he couldnīt do it after the other asked him to decrease acceleration?
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Sure, while on the tarmac and reversers being already deployed - since this is about the first thing you do. Dreamland, may I quote yourself:
My guess is that it would have flown at around 100 KTS. 
So. My revised list of what I would think AB engineers should change:
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Dream Land
It sounds from your post that you may have a valuable experience to share with us, which may well be relevant to this accident? Could you please tell us more?
TP
I will tell you from experience that applying brakes in this case (one engine producing loads of thrust, 63 tonnes, slippery, Vapp 145 KTS)without ground spoiler activation would be a total waste of time,
TP