TAM A320 crash at Congonhas, Brazil
marciovp;
Well, at the risk of scratching the same skin dozens of times over again, if it is hard for you sir, think of how hard it is for the manufacturers to think the same thing.
Before this accident, if someone has posited the scenario on PPRuNe, would you or anyone here have ever given creedance or even entertained the (wild) notion that thrust levers would/could possibly be left in any other position than idle, in any design, A or B, upon landing? I think not.
Whether it is cables-and-pulleys, bell-cranks-and-pushrods, or sensors-resolvers-and-software the potential for this accident always existed but no aircraft manufacturer ever considered the need to warn crews of the very scenario you describe. Shall automobile designers anticipate that drivers will keep their foot on the gas pedal while braking heavily for a stop-sign? Where are the bounds of the reasonable? Unless we have a situation where there is a physical disconnect under the pedestal, an impediment to retarding the TL above, or a FADEC issue, this is no more an "Airbus/computer/thrust lever" matter than it is a Ford, Audi, BMW or GM gas-and-brake-pedal matter.
Now the industry must deal with the human factors and industrial design work that may be needed to prevent what will almost certainly be a rare-if-ever re-occurrence.
That response is something quite different than "never having anticipated the inconceivable".
georgecrock;
Wow.
PJ2
... it is hard for me to conceive that a plane with a TL on climb detent and the other on reverser with the pilot trying to apply the brakes remains silent...
Before this accident, if someone has posited the scenario on PPRuNe, would you or anyone here have ever given creedance or even entertained the (wild) notion that thrust levers would/could possibly be left in any other position than idle, in any design, A or B, upon landing? I think not.
Whether it is cables-and-pulleys, bell-cranks-and-pushrods, or sensors-resolvers-and-software the potential for this accident always existed but no aircraft manufacturer ever considered the need to warn crews of the very scenario you describe. Shall automobile designers anticipate that drivers will keep their foot on the gas pedal while braking heavily for a stop-sign? Where are the bounds of the reasonable? Unless we have a situation where there is a physical disconnect under the pedestal, an impediment to retarding the TL above, or a FADEC issue, this is no more an "Airbus/computer/thrust lever" matter than it is a Ford, Audi, BMW or GM gas-and-brake-pedal matter.
Now the industry must deal with the human factors and industrial design work that may be needed to prevent what will almost certainly be a rare-if-ever re-occurrence.
That response is something quite different than "never having anticipated the inconceivable".
georgecrock;
Wow.
PJ2
Last edited by PJ2; 22nd Sep 2007 at 21:05.
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Originally Posted by armchairpilot in the Sunset District
I am not certain the TAM flight wouldve stopped on a 2400 meter runway either
PBL
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Good point...
Before this accident, if someone has posited the scenario on PPRuNe, would you or anyone here have ever given creedance or even entertained the (wild) notion that thrust levers would/could possibly be left in any other position than idle, in any design, A or B, upon landing? I think not.
But after three accidents when landing with one reverser locked, should the AB look at it and see if it could help some?
I guess the same would happen if there were three accidents with one particular car by the motorist pusahing the brake and accelerator at the same time (where they too close? etc, etc).
Common sense, no?
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to PBL
Yes I know. We have both been through the whole thread. However, I just want to personally dis-agree with those calculations. Simply because we are not talking about a crew that knew what would happen and would therefore take immediate action. But instead a "human" crew who needed valuable seconds to decipher what was happening to any extent and to take any action (ie stomp on brakes). Both crews (TAM and Transasia) started braking hard as fast as humanly possible and landed within the normal touchdown zone as well. The TAM crew had the added dis-advantage of a higher EPR as well on number two.
I believe there wouldve been an overrun as well in TAM's case. But like Taipei , it wouldve been relegated to the minor accident category instead of major. If the TAM crew had that accident at TAipei. LIkely the outcome wouldve been almost identical to Transasia's. Except the higer EPR may have resulted in a bit more aircraft damage and/or some minor injuries to passengers or crew.
Well we are just splitting hairs here. But a 2400 meter runway would've saved the day for TAM. That is not in doubt.
Yes I know. We have both been through the whole thread. However, I just want to personally dis-agree with those calculations. Simply because we are not talking about a crew that knew what would happen and would therefore take immediate action. But instead a "human" crew who needed valuable seconds to decipher what was happening to any extent and to take any action (ie stomp on brakes). Both crews (TAM and Transasia) started braking hard as fast as humanly possible and landed within the normal touchdown zone as well. The TAM crew had the added dis-advantage of a higher EPR as well on number two.
I believe there wouldve been an overrun as well in TAM's case. But like Taipei , it wouldve been relegated to the minor accident category instead of major. If the TAM crew had that accident at TAipei. LIkely the outcome wouldve been almost identical to Transasia's. Except the higer EPR may have resulted in a bit more aircraft damage and/or some minor injuries to passengers or crew.
Well we are just splitting hairs here. But a 2400 meter runway would've saved the day for TAM. That is not in doubt.
marciovp;
No. And to frame the question only in terms of "is it or is it not" [common sense] precludes alternative (and more interesting) thinking and consequent appropriate responses.
I suspect there are literally millions of rear-end collisions caused by hitting either the clutch pedal or the gas instead of the brake and more than likely both, even using both feet. It's a car. What do should designers do with that? Build "protective" shields against stupidity or incompetence? We all know that both characteristics exist on our roads no matter where each of us are drivers. In fact, let me pose the question to anyone who thinks that designers should take full responsibility in fool-proofing machinery whether through sophisticated software or mechanical latches: What are they [vice us] prepared to do about the 46,000 people killed on the roads in the US each year, (a full 747 crashing about every 3 days)? Is the question realistic? Are the highway engineeers doing their job? Are all accidents caused by pedal confusion? Sorry...I digress.
What level of training, consequent awareness and address must be assumed in design before it is the participants and not the designers who must accept increasing levels of responsibility?
In aviation, a designer has every right to expect a level of competence and specialized, intensive training and even directs it when airlines/corporations buy their products. It is a proven fact that where training falls well short of these goals, accidents are going to happen*. Shall designers pick up the slack? Again, I don't think so. The fact that this regime exists in such strict processes and regulatory requirements is sufficient support for this point; these requirements exist to ensure that the designer's job is reasonable and affordable while at the same time a product is produced which does not take test-pilot skills, a photographic memory or Olympian dexterity to operate.
For consideration....
PJ2
*Please note that I am not implying anything regarding the TAM crew here but am making these points generically. The argument nevertheless is valid.
But after three accidents when landing with one reverser locked, should the AB look at it and see if it could help some?
I guess the same would happen if there were three accidents with one particular car by the motorist pusahing the brake and accelerator at the same time (where they too close? etc, etc).
Common sense, no?
I guess the same would happen if there were three accidents with one particular car by the motorist pusahing the brake and accelerator at the same time (where they too close? etc, etc).
Common sense, no?
I suspect there are literally millions of rear-end collisions caused by hitting either the clutch pedal or the gas instead of the brake and more than likely both, even using both feet. It's a car. What do should designers do with that? Build "protective" shields against stupidity or incompetence? We all know that both characteristics exist on our roads no matter where each of us are drivers. In fact, let me pose the question to anyone who thinks that designers should take full responsibility in fool-proofing machinery whether through sophisticated software or mechanical latches: What are they [vice us] prepared to do about the 46,000 people killed on the roads in the US each year, (a full 747 crashing about every 3 days)? Is the question realistic? Are the highway engineeers doing their job? Are all accidents caused by pedal confusion? Sorry...I digress.
What level of training, consequent awareness and address must be assumed in design before it is the participants and not the designers who must accept increasing levels of responsibility?
In aviation, a designer has every right to expect a level of competence and specialized, intensive training and even directs it when airlines/corporations buy their products. It is a proven fact that where training falls well short of these goals, accidents are going to happen*. Shall designers pick up the slack? Again, I don't think so. The fact that this regime exists in such strict processes and regulatory requirements is sufficient support for this point; these requirements exist to ensure that the designer's job is reasonable and affordable while at the same time a product is produced which does not take test-pilot skills, a photographic memory or Olympian dexterity to operate.
For consideration....
PJ2
*Please note that I am not implying anything regarding the TAM crew here but am making these points generically. The argument nevertheless is valid.
Last edited by PJ2; 22nd Sep 2007 at 23:59.
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marciovp
You have to be familiar with the concept of DDG or "Dispatch Deviation Guide", from which the already mentioned MEL "Minimum Equipment List" is derived : Due to the built-in redundancies in an aircraft an equipment could be inoperative without impairing the safety of its operations. You then have, after some serious statistic computations a decision on the airworthiness of this said aircraft, the faulty item is either a *no GO* or a MELed item of which there are several classes of period - be it in airframe hours or a number of sectors or a number of days before which the failure is fixed. Items are classified as A,B,C or D in order of decreasing importance.
Furthermore, each MELed item comes with a maintenance procedure ( here the locking of the reverser and the verification that the EEC / FADEC has recognised the inoperability of the reverser ), a crew procedure (here the use of both T/Ls ) and a dispatch limitation (Ops on contaminated runways forbidden, for instance ).
The final decision on the aircraft dispatch with one - or more - MELed systems on the ATL is the Captain's.
Why ten days ? First of all it is the maximum period the aircraft is allowed to fly with this defect. Unless the DGCA authorizes for special reasons the extension of the period (the aircraft unable to return to base in time, for instance), the aircraft is grounded until repair is made. As the T/R is not, in most cases, required in normal good weather operations, ten days it is .
PJ2
My sentiment, entirely.
You have to be familiar with the concept of DDG or "Dispatch Deviation Guide", from which the already mentioned MEL "Minimum Equipment List" is derived : Due to the built-in redundancies in an aircraft an equipment could be inoperative without impairing the safety of its operations. You then have, after some serious statistic computations a decision on the airworthiness of this said aircraft, the faulty item is either a *no GO* or a MELed item of which there are several classes of period - be it in airframe hours or a number of sectors or a number of days before which the failure is fixed. Items are classified as A,B,C or D in order of decreasing importance.
Furthermore, each MELed item comes with a maintenance procedure ( here the locking of the reverser and the verification that the EEC / FADEC has recognised the inoperability of the reverser ), a crew procedure (here the use of both T/Ls ) and a dispatch limitation (Ops on contaminated runways forbidden, for instance ).
The final decision on the aircraft dispatch with one - or more - MELed systems on the ATL is the Captain's.
Why ten days ? First of all it is the maximum period the aircraft is allowed to fly with this defect. Unless the DGCA authorizes for special reasons the extension of the period (the aircraft unable to return to base in time, for instance), the aircraft is grounded until repair is made. As the T/R is not, in most cases, required in normal good weather operations, ten days it is .
PJ2
In aviation, a designer has every right to expect a level of competence and specialized, intensive training and even directs it when airlines/corporations buy their products. It is a proven fact that where training falls well short of these goals, accidents are going to happen
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Nice discussion
I suspect there are literally millions of rear-end collisions caused by hitting either the clutch pedal or the gas instead of the brake and more than likely both, even using both feet. It's a car. What do should designers do with that? Build "protective" shields against stupidity or incompetence? We all know that both characteristics exist on our roads no matter where each of us are drivers.
Shall designers pick up the slack?
Why ten days ? First of all it is the maximum period the aircraft is allowed to fly with this defect.
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armchairpilot
Look at it from another perspective :
First
1/- The airplane landed at CGH on runway 35L.
That runway is 1940m long and the LDA - landing distance available - is 1880m.
The METAR reports at 1720 was :340/08 6000m RA BKN 900 ft OVC 7000 ft Temps 16 / 14 QNH 1018 hPa
2/- Some pilots noticed standing water on the runway, which wasn't grooved.
We can then assume that, according to :
Now let's just take -again - the A320 QRH that gives us the required *in-flight* performance of the type :
At a landing weight of 62 tons, the required landing distances are :
for dry runway : 1490 m
for wet runway : 1690 m
for 3 to 6 mm of standing water : 2130 m
Those are the baseline figures for sea level and OAT < 40° C, without reversers and without auto brakes.
Congonhas being 2600 ft above sea level, a correction of 3% per thousand feet applies for a wet runway, and 4% for 3 to 6 mm of standing water.
The resulting landing distances then became :
for a wet runway : 1690 x 107.5% = 1822 m
for standing water :2130 x 110.5% = 2354 m
Considering the built-in margins in these performances computations, you'll have to answer two questions :
I just want to personally dis-agree with those calculations. Simply because we are not talking about a crew that knew what would happen and would therefore take immediate action. But instead a "human" crew who needed valuable seconds to decipher what was happening to any extent and to take any action (ie stomp on brakes).
First
1/- The airplane landed at CGH on runway 35L.
That runway is 1940m long and the LDA - landing distance available - is 1880m.
The METAR reports at 1720 was :340/08 6000m RA BKN 900 ft OVC 7000 ft Temps 16 / 14 QNH 1018 hPa
2/- Some pilots noticed standing water on the runway, which wasn't grooved.
We can then assume that, according to :
- the published METAR
- The Pilot Report
- the noise of the windshield wiper on the CVR,
Now let's just take -again - the A320 QRH that gives us the required *in-flight* performance of the type :
At a landing weight of 62 tons, the required landing distances are :
for dry runway : 1490 m
for wet runway : 1690 m
for 3 to 6 mm of standing water : 2130 m
Those are the baseline figures for sea level and OAT < 40° C, without reversers and without auto brakes.
Congonhas being 2600 ft above sea level, a correction of 3% per thousand feet applies for a wet runway, and 4% for 3 to 6 mm of standing water.
The resulting landing distances then became :
for a wet runway : 1690 x 107.5% = 1822 m
for standing water :2130 x 110.5% = 2354 m
Considering the built-in margins in these performances computations, you'll have to answer two questions :
- Should the airplane have been dispatched to CGH, considering the weather, the state of the runway conditions with an inop T/R ?
- Would a 2,400 m runway been enough for them to stop ?(Considering that above-average skills are not required to achieve those performances )
marciovp;
No, it is not a "big" change. Good heavens, give professional, trained flight crews a little credit, sir.
Every aircraft carries "dangerous", (to employ hyperbole), possibilities, marciovp, . Those possibilities can be found in the Library of Babel.
In the real world of engineering and piloting, there are practical limitations to possibilities with which both groups unremarkably come to terms on a regular and ordinary basis in complete safety.
You are setting up infinite possibilities as an argument and that is, by definition, an impossible task to resolve. Have a nice weekend.
That is a big change insofar as he is used to...
. . . .
But if I built a plane that carries this possibility with these terrible consequences I would make sure, besides the Mels, to have the software help the pilot caught in this dangerous predicament.
. . . .
But if I built a plane that carries this possibility with these terrible consequences I would make sure, besides the Mels, to have the software help the pilot caught in this dangerous predicament.
Every aircraft carries "dangerous", (to employ hyperbole), possibilities, marciovp, . Those possibilities can be found in the Library of Babel.
In the real world of engineering and piloting, there are practical limitations to possibilities with which both groups unremarkably come to terms on a regular and ordinary basis in complete safety.
You are setting up infinite possibilities as an argument and that is, by definition, an impossible task to resolve. Have a nice weekend.
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to Lemurian
I'm with you on this one. I predict the aircraft would've overrun even with a runway length of 2400 meters. And at Congonhas with that cliff to fall off of, this is still not a good thing. And one can only hope the little Runway End Zone available would be able to contain the overrun. Otherwise, some deaths and/or major injuries would still have to be expected if it falls off onto the freeway below.
No, the aircraft should not have been dispatched to Congonhas under those conditions of course.
Congonhas should have EMAS and strict flight guidelines for A320/737 operations IMHO.
I'm with you on this one. I predict the aircraft would've overrun even with a runway length of 2400 meters. And at Congonhas with that cliff to fall off of, this is still not a good thing. And one can only hope the little Runway End Zone available would be able to contain the overrun. Otherwise, some deaths and/or major injuries would still have to be expected if it falls off onto the freeway below.
No, the aircraft should not have been dispatched to Congonhas under those conditions of course.
Congonhas should have EMAS and strict flight guidelines for A320/737 operations IMHO.
Last edited by armchairpilot94116; 23rd Sep 2007 at 04:41.
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armchairpilot
That's not quite what my post says or the second question asks.
marciovp
That procedure only existed in your dreams.
It has always been to retard both T/Ls to idle first. Then the selection of either reverser or both at the same time is a non-event.
On a four-engined airplane, the procedure was even more subtle as one would first retard all to idle ,then select idle reverse with all levers and in case of one T/R not deploying -or a deactivated T/R - reverse only on the remaining symetrical T/Rs (if #1 inop, reverse only on #2 and 3 ; if #3 inop, use #1 and 4...etc...). No big deal at all.
In my experience, thrust reversers are, with APU faults, the defects one is most likely to find on the ATL upon taking charge of a flight and it has never been a concern in normal operations.
Once again, I know of an airline which flies more than a thousand sectors every day, come rain or come shine and that airline has never had a problem with T/R handling with an inop reverser.
In fact, the only mishandlings that have been found on the -required- recorder fast readings were, for new pilots on their training flights, a tendency to throttle down too slowly on an ATHR-on landing, causing the aircraft to float a bit. That's easily cured.
As said before, just a matter of training.
Have you noticed that your arguments are getting wilder and wilder ?
I'm with you on this one. I predict the aircraft would've overrun even with a runway length of 2400 meters.
marciovp
Well, occasionally, I would say rarely this procedure changes: the pilot now has to pul ONE TL to Idle and Rev...He is not used doing his, pulling ONE TL?... and then he must pull the other TL but stop in Idle... That is a big change insofar as he is used to...
It has always been to retard both T/Ls to idle first. Then the selection of either reverser or both at the same time is a non-event.
On a four-engined airplane, the procedure was even more subtle as one would first retard all to idle ,then select idle reverse with all levers and in case of one T/R not deploying -or a deactivated T/R - reverse only on the remaining symetrical T/Rs (if #1 inop, reverse only on #2 and 3 ; if #3 inop, use #1 and 4...etc...). No big deal at all.
In my experience, thrust reversers are, with APU faults, the defects one is most likely to find on the ATL upon taking charge of a flight and it has never been a concern in normal operations.
Once again, I know of an airline which flies more than a thousand sectors every day, come rain or come shine and that airline has never had a problem with T/R handling with an inop reverser.
In fact, the only mishandlings that have been found on the -required- recorder fast readings were, for new pilots on their training flights, a tendency to throttle down too slowly on an ATHR-on landing, causing the aircraft to float a bit. That's easily cured.
As said before, just a matter of training.
Have you noticed that your arguments are getting wilder and wilder ?
Last edited by Lemurian; 23rd Sep 2007 at 09:55.
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Good points, of course... but...
You are setting up infinite possibilities as an argument and that is, by definition, an impossible task to resolve. Have a nice weekend.
I guess they did think like me...
Have you noticed that your arguments are getting wilder and wilder ?
PJ2 is right: letīs enjoy the weekend. I am watching the Brazilian female soccer team play against Australia... Good game!
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Originally Posted by marciovp
why did AB came up with a new software (US$5000.00) that keep warning the pilots about the TL on climb?
AI respond to customer requests. They presumably responded to one from TAM. Why might they have done it? Because they were asked to do so.
I do not see what is so insidious about responding to customer requests.
PBL
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Not so PBL...sorry...
AI respond to customer requests. They presumably responded to one from TAM. Why might they have done it? Because they were asked to do so.
I keep harping on it because, right or wrong this makes sense to me and because I like to know what can be done to prevent a fourth disaster like this one.
PS. Insofar as the letter from China I am waiting for my friend to get back at me to say what he has learned about it. I did not forget.
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This is a really interesting and informative thread, congratulations to all contributors.
What I find fascinating is that despite having the most modern aircraft technology at their disposal, two experienced AB320 pilots may have caused this accident by failing to pull one of the TLs to idle as the aircraft was touching down. If so, it would seem to be a colossal blunder, in the same league as the sinking of the 'Herald of Free Enterprise' which happened because the captain sailed out to sea with the ship's bow doors open (see http://en.wikipedia.org/wiki/Zeebrugge_ferry_disaster). Clearly, 'Murphy's Law' is still alive and well!
The following extract from http://www.airdisaster.com/forums (dated Nov 24 2001) hints that only a fairly incompetent pilot would fail to retard the thrust levers when close to touchdown.
When considering ways of preventing similar accidents arising in the future, perhaps changes should be made to crew selection rather than messing around with the existing AirBus systems. The following link suggests that having more female pilots (tongue firmly in cheek) might help:
What I find fascinating is that despite having the most modern aircraft technology at their disposal, two experienced AB320 pilots may have caused this accident by failing to pull one of the TLs to idle as the aircraft was touching down. If so, it would seem to be a colossal blunder, in the same league as the sinking of the 'Herald of Free Enterprise' which happened because the captain sailed out to sea with the ship's bow doors open (see http://en.wikipedia.org/wiki/Zeebrugge_ferry_disaster). Clearly, 'Murphy's Law' is still alive and well!
The following extract from http://www.airdisaster.com/forums (dated Nov 24 2001) hints that only a fairly incompetent pilot would fail to retard the thrust levers when close to touchdown.
PAX Question:
One more thing, from my usual seat I can hear a voice coming from the flight deck just before touchdown that is computerized and I swear it says "retard retard retard".
Is that right? What does this mean?
Pilot's Answer:
Yes that's right, it's telling us to "retard" the engine thrust levers to the idle position for landing. I guess the Airbus engineers figured that because the levers don't move with the autothrust system that some of us dumb pilots might forget ? It's standard on all A320's, and you can order it with the sexy female voice option if you want.
One more thing, from my usual seat I can hear a voice coming from the flight deck just before touchdown that is computerized and I swear it says "retard retard retard".
Is that right? What does this mean?
Pilot's Answer:
Yes that's right, it's telling us to "retard" the engine thrust levers to the idle position for landing. I guess the Airbus engineers figured that because the levers don't move with the autothrust system that some of us dumb pilots might forget ? It's standard on all A320's, and you can order it with the sexy female voice option if you want.
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Lemurian
Q1 = NO
Q2 = NO
I like your presentation of the situation, and I would think a reasonable dispatcher would've sent that aircraft elsewhere that night if he had that page in front of him. Another slice of swiss cheese with a big hole to line up with.
However, I do think that the aircraft would've stopped on the runway IF both T/L were brought to idle even if one reverser was inop.
I understand that Brazilian authorities now forbid aircraft to land at Congonhas with a reverser inop now?
Q1 = NO
Q2 = NO
I like your presentation of the situation, and I would think a reasonable dispatcher would've sent that aircraft elsewhere that night if he had that page in front of him. Another slice of swiss cheese with a big hole to line up with.
However, I do think that the aircraft would've stopped on the runway IF both T/L were brought to idle even if one reverser was inop.
I understand that Brazilian authorities now forbid aircraft to land at Congonhas with a reverser inop now?
Last edited by armchairpilot94116; 24th Sep 2007 at 02:28.
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Yes armchair
I understand that Brazilian authorities now forbid aircraft to land at Congonhas with a reverser inop now?
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armchairpilot
Huh ? Mathematically, 2354 < 2400 . Correct ?
Go back to the TranAsia accident report, have a look at the *scenarii* AI (not AB) had computed and see the spread of landing distances.
The computations made on this forum, to the best of my judgement are valid, both in terms of the assumed decelerations and stopping distances, and are validated by these data.
Of course, you still can go along splitting hairs "the EPR valur was greater "... Yes, but the deceleration graph originally shows that a small deceleration was achieved without brakes or reversers which proves that initially drag and ground friction more than balanced the generated forward thrust on #2 engine.
Then you could go on , on the stress in that cockpit... I dare say that the emergency dawned on them relatively later than the touch-down and the unavailability of the ground spoilers. See bsieker's WBA graph (at least someone agrees with me ).
The main difficulty in discussing with you or marciovp is that you seem to refuse engineering evidence and physics.
Where both your arguments err is when you start factoring physics with human factors no one knows as we were not in this cockpit. We can explain how this accident happened, putting figures and timing to the FDR/CVR data but we will never understand the multiple *whys*. It's for someone else greater and higher than me.
On the other hand, the *prophylaxys* of such an accident lie heavily on -I say it again -quality of training, Adherence to SOPs, Quality Documentation, Quality Dispatch Department ...
In this respect, TAM's OPS Department will be on the front of the firing line.
I've said enough. I won't discuss these points any more.
As for letters and references from Marcio, I think they made their point themselves.
Adeus !
Q2 = NO
Go back to the TranAsia accident report, have a look at the *scenarii* AI (not AB) had computed and see the spread of landing distances.
The computations made on this forum, to the best of my judgement are valid, both in terms of the assumed decelerations and stopping distances, and are validated by these data.
Of course, you still can go along splitting hairs "the EPR valur was greater "... Yes, but the deceleration graph originally shows that a small deceleration was achieved without brakes or reversers which proves that initially drag and ground friction more than balanced the generated forward thrust on #2 engine.
Then you could go on , on the stress in that cockpit... I dare say that the emergency dawned on them relatively later than the touch-down and the unavailability of the ground spoilers. See bsieker's WBA graph (at least someone agrees with me ).
The main difficulty in discussing with you or marciovp is that you seem to refuse engineering evidence and physics.
Where both your arguments err is when you start factoring physics with human factors no one knows as we were not in this cockpit. We can explain how this accident happened, putting figures and timing to the FDR/CVR data but we will never understand the multiple *whys*. It's for someone else greater and higher than me.
On the other hand, the *prophylaxys* of such an accident lie heavily on -I say it again -quality of training, Adherence to SOPs, Quality Documentation, Quality Dispatch Department ...
In this respect, TAM's OPS Department will be on the front of the firing line.
I've said enough. I won't discuss these points any more.
As for letters and references from Marcio, I think they made their point themselves.
Adeus !
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Originally Posted by marciovp
TAM did not ask for it. AB ofered it after the accident in Taipei but did not make it mandatory. TAM did not buy it. Now, of course they are saying that all their planes will have it.
PBL
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Lemurian
Going by your figures you gave:
LDA at Congonhas 1880 m
Landing distance required with no reversers and no autobrake at Congonhas: Wet = 1822 , Standing water = 2354
These are distances required not runway length right? They will not be able to TD right at the very beginning of the runway yes? Even on a 2400 M runway they may TD at say the 300 M mark? leaving 2100 meters? And if reversers inop and no autobrake on a runway with standing water they may still overrun no?
What am I missing here?
NOw in reality they had one reverser (the other engine still pushing forward though) and they had no autobrake.
The TAipei crew took a few seconds to realize NO BRAKE and started manual braking. They did NOT stop on a nearly 2600 meter runway in a very similar configuration to the TAM flight. What makes you think the TAM crew wouldve stopped their A320 in an almost identical configuration even if Congonhas was 2400 meters?
They "mightve" stopped on Congonhas with its LDA 1880 meter IF both T/L were at idle because autobrake and spoilers would be working as they should be.
Again, what am I missing here?
Going by your figures you gave:
LDA at Congonhas 1880 m
Landing distance required with no reversers and no autobrake at Congonhas: Wet = 1822 , Standing water = 2354
These are distances required not runway length right? They will not be able to TD right at the very beginning of the runway yes? Even on a 2400 M runway they may TD at say the 300 M mark? leaving 2100 meters? And if reversers inop and no autobrake on a runway with standing water they may still overrun no?
What am I missing here?
NOw in reality they had one reverser (the other engine still pushing forward though) and they had no autobrake.
The TAipei crew took a few seconds to realize NO BRAKE and started manual braking. They did NOT stop on a nearly 2600 meter runway in a very similar configuration to the TAM flight. What makes you think the TAM crew wouldve stopped their A320 in an almost identical configuration even if Congonhas was 2400 meters?
They "mightve" stopped on Congonhas with its LDA 1880 meter IF both T/L were at idle because autobrake and spoilers would be working as they should be.
Again, what am I missing here?
Last edited by armchairpilot94116; 24th Sep 2007 at 09:09. Reason: mightve for wouldve per BOAC suggestion, which I agree