TACA aircraft crashed in Honduras
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bubbers44,
The 70 knot call was 7 seconds before hitting the fence and going off the cliff. He was reducing reverse before the 70 knot call so must have thought all was well at that time.
Why at 70 knots couldn't he stop in that 7 seconds or go back to max reverse thrust if rubber deposits reduced his braking? I know nothing except what I have learned here on Airbus 320 logic but it seems he lost all braking shortly after that call of 70 knots.
I said it before but that last 1000 feet should be for emergency stopping only. Once slowed down to a safe speed use it to save brake wear and temp.
One of the reasons why this transcript is galling is that most of the cockpit preparation is not there : For instance, the crew referrred to a *MEMO* that they cancelled. What was on that memo pad ? Some posters have also noticed that the discrepancy between *Manual braking* and *Decel* is at least very puzzling.
What is left for us to ponder about is that the deceleration from the touch-down speed and 70 kt was normal, even stronger than we'd expect from a medium autobrake setting (I stick to my figures)...
There is also the *Single Chime* recorded which is very probabbly related to a minor failure showing after 80 kt (phase 8 inhibition)...what was it ? Was it related to the braking system ? In which case the "Cancel the..." makes sense as in "Switch the Anti-skid off..." (But here I digress and there is nothing to back that theory up, especially when they seemed to have had some effective braking prior to that point).
rwa,
As far as I can work out (such technical knowledge as I have is in another field) at that time any problem with the 'Anti-Skid and Nosewheel Steering' showed up only as a 'STEERING' warning. Cycling the switch removed the warning; but it ALSO cancelled the autobrake setting, and there was no warning message about that.
That incident comes from 1/- some very flippant conceptions of SOPs, and 2/- an incomplete knowledge of the airplane systems and emergency procedures. I might add that 1 and 2 generally go in pairs.
Why ?
1/-Where in their manual have they found that *switch cycling procedure* ?
Not on the FCOMS I've used.
2/- *LOSS OF BRAKING* is one of the 9 memory drills on the 320. They are :
- Emergency descent
- Unreliable IAS
- Oxygen masks
- Loss of braking
- Engine surge
- Pull up TOGA
- Aborted T/O
- TCAS resolution
- Windshear TOGA
The crew in the incident you referred to did not know their drills. Final.
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Lemurian,
Neatly dodged.Blame the crew.Did Airbus introduce this NNC before or after these incidents?Were they responding to the loss of braking incidents or did they fully realise at the design stage that a complete loss of braking was possible and that the reasons for this loss would not be readily apparent to the crew(or indicated to the crew!) such that a NNC would have to be implemented?
Now if Airbus ever promote you to PR chief,I am going out and buying all the EADS shares I can because I think you could sell freezers to the eskimos.
That incident comes from 1/- some very flippant conceptions of SOPs, and 2/- an incomplete knowledge of the airplane systems and emergency procedures. I might add that 1 and 2 generally go in pairs.
Now if Airbus ever promote you to PR chief,I am going out and buying all the EADS shares I can because I think you could sell freezers to the eskimos.
• DECEL or ‘decel’:
If the call was based on auto-brake DECEL light it suggests that auto-brake was engaged and that the deceleration was at least 80% of what ever was selected. There are too many unknowns here to be of use, other than the assumption that at the time of the call the system was working.
Alternatively, if the SOP was to call ‘decel’ based on the PFD speed trend, then the conclusion is that aircraft was decelerating. However, without knowing what value the SOP uses, when the SOP is used (manual braking only), or the specifics of the PFD speed trend – IAS or IAS inertial mix (probably not pure deceleration in a GS sense – N.B. tailwind), then again, no great value in understanding what is happening.
• Re manual braking if auto-brake is perceived to have failed:
How is auto brake failure deduced? Is manual braking used when there is no DECEL lamp / call, if so what level of braking is advised?
If brake failure / ineffectiveness is expected to be judged by human senses, then both auto- and manual braking depend on ‘seat–of-the-pants’ assessment (inertial deceleration); manual has the additional cue from foot-force (position) feedback of the demanded level of braking.
Anyone use a brake pressure gauge, if so what does it show?
• Reduced (failed) braking:
I disagree with the assertion that “The kind of deceleration we are talking about here will be felt, …” (#296).
If the runway condition involved low friction, then the majority of the deceleration would come from reverse. After cancelling reverse, the relative ineffectiveness of the brakes could be perceived as a failure. The decel level from braking is less ‘negative’ than reverse, thus the change of body sensed acceleration is in a positive sense, which could be deduced to be a system failure opposed to a human attribute.
Problems in this area stem from training / experience, where IMHO crews are not familiar with maximum manual braking on a wet runway; auto-brake removes an important cue, and with everyday use of reverse, it masks the brake contribution to the total deceleration. (see ref – Boeing briefing)
Full manual braking on a moderately wet runway can result in an uneasy feeling of not stopping where you expect. Furthermore many pilots have misgivings about the use of maximum braking with fears of tyre burst etc – there should be none. Braking systems are certificated for maximum use at any time; if pax comfort is quoted then the safety priorities are incorrect.
The only system failure in the above of the scenario is that of human perception – a known weakness, which can be exacerbated by poor training, inadequate SOPs, and low experience. There is no evidence of the latter contributions, but the human factor is always present.
Ref: Flt Ops / Flying Technique … Landing on Slippery Runways.
If the call was based on auto-brake DECEL light it suggests that auto-brake was engaged and that the deceleration was at least 80% of what ever was selected. There are too many unknowns here to be of use, other than the assumption that at the time of the call the system was working.
Alternatively, if the SOP was to call ‘decel’ based on the PFD speed trend, then the conclusion is that aircraft was decelerating. However, without knowing what value the SOP uses, when the SOP is used (manual braking only), or the specifics of the PFD speed trend – IAS or IAS inertial mix (probably not pure deceleration in a GS sense – N.B. tailwind), then again, no great value in understanding what is happening.
• Re manual braking if auto-brake is perceived to have failed:
How is auto brake failure deduced? Is manual braking used when there is no DECEL lamp / call, if so what level of braking is advised?
If brake failure / ineffectiveness is expected to be judged by human senses, then both auto- and manual braking depend on ‘seat–of-the-pants’ assessment (inertial deceleration); manual has the additional cue from foot-force (position) feedback of the demanded level of braking.
Anyone use a brake pressure gauge, if so what does it show?
• Reduced (failed) braking:
I disagree with the assertion that “The kind of deceleration we are talking about here will be felt, …” (#296).
If the runway condition involved low friction, then the majority of the deceleration would come from reverse. After cancelling reverse, the relative ineffectiveness of the brakes could be perceived as a failure. The decel level from braking is less ‘negative’ than reverse, thus the change of body sensed acceleration is in a positive sense, which could be deduced to be a system failure opposed to a human attribute.
Problems in this area stem from training / experience, where IMHO crews are not familiar with maximum manual braking on a wet runway; auto-brake removes an important cue, and with everyday use of reverse, it masks the brake contribution to the total deceleration. (see ref – Boeing briefing)
Full manual braking on a moderately wet runway can result in an uneasy feeling of not stopping where you expect. Furthermore many pilots have misgivings about the use of maximum braking with fears of tyre burst etc – there should be none. Braking systems are certificated for maximum use at any time; if pax comfort is quoted then the safety priorities are incorrect.
The only system failure in the above of the scenario is that of human perception – a known weakness, which can be exacerbated by poor training, inadequate SOPs, and low experience. There is no evidence of the latter contributions, but the human factor is always present.
Ref: Flt Ops / Flying Technique … Landing on Slippery Runways.
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Originally Posted by Lemurian
There is also the *Single Chime* recorded which is very probabbly related to a minor failure showing after 80 kt (phase 8 inhibition)...what was it ? Was it related to the braking system ? In which case the "Cancel the..." makes sense as in "Switch the Anti-skid off..." (But here I digress and there is nothing to back that theory up, especially when they seemed to have had some effective braking prior to that point).
) we both tend to agree with each other sometimes.......Agree especially that 'Cancel, cancel the...." could well have related to the Anti-Skid.
A bit like the old joke that if you gave a couple of monkeys a box of ballpoints, enough paper, and enough time, they'd eventually finish up writing the complete works of Shakespeare. Between us we seem to have made a fair start on 'Hamlet'........
My own view is that yes, maybe they DID have some braking - but that its effect may have been severely restricted by the 'Anti-Skid,' given that they were still travelling pretty fast on a damp runway. Alternatively, since as far as I know the 'decel' light depends on inertia, it could just have been the combined effect of the spoilers and reversers - the F/O seeing what he desperately WANTED to see.
Originally Posted by Lemurian
If one considers that some of them are so obvious as to be rather insulting to us pilots like aborted T/O, we are left with a very few number of specific procedures, among which *Loss of Braking"
Perhaps you could get a bit constructive and tell us all what the A320 crew manual actually says about 'Loss Of Braking?'
And also, as Rananim asks, whether it has been revised recently?
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despite your precautions
I'm all for informing anyone asking perfectly legitimate questions. I'm certainly not going to let pass some ambulance chasers by without reacting.
You, and your other avatar are trying to prove...what ? That Airbus is chasing on the holy ground of Boeing and should be burned and A pilots should be locked in asylums ?
Actually, you are so imbued of your righteousness that you fall in every trap I lay for you : As it has been proven by their early deceleration that they had working brakes, the failure I referred to is as unlikely as being impossible.
My own view is that yes, maybe they DID have some braking -
that its effect may have been severely restricted by the 'Anti-Skid,' given that they were still travelling pretty fast on a damp runway.
I'd wish you'd see your mission as being to inform and educate us
Perhaps you could get a bit constructive and tell us all what the A320 crew manual actually says about 'Loss Of Braking?'
In fact, the way this forum goes, there are several kinds of posters :
- Those who want to understand how things are, what happened
- Those who have some of the answers
- Those who have an understanding of the situation but want more information
- Those with an agenda ( here it is to prove that it can't happen on anything but an Airbus )
Now you know whom my ignore list is composed of. ( you're not there, you amuse me too much ).
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My question was, Lemurian:-
If you choose not to answer it - or, very possibly, don't even know what the answer is - don't worry, I understand.
I think........
Originally Posted by RWA
[Perhaps you could get a bit constructive and tell us all what the A320 crew manual actually says about 'Loss Of Braking?'
And also, as Rananim asks, whether it has been revised recently?
And also, as Rananim asks, whether it has been revised recently?
I think........
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A/B Med = 3m/s/s decel rate, progressively applied starting 2 secs after ground spoiler deployment.
Decel Light comes on when actual deceleration is 80% of the selected rate.
"On slippery runway, the predetermined deceleration may not be reached due to antiskid operation. In this case, DECEL light will not illuminate. This does not mean that A/B is not working."
But, they went on manual braking anyways... so we're down to the antiskid?
Antiskid should operate until down to 20kts GNDSPD.
I'm quite interested in that single chime about 4 secs after the 70 kts call. I assume the 70kts was IAS, and that the aircraft was about 80kts gndspeed given the 10kt tailwind, and higher GND SPD with the altitude, hence it is either in phase 8 or 9 of the flight.
On those 2 phases, on braking, the chime can come from hot brakes, A/B fault when armed, or HYD SEL FAULT (failure of brake normal selector valve or NWS selector valve in open position)... the only one extending to phase 9 is A/B fault when armed.
Now a BSCU fault would not yield the chime, the A/B fault shouldn't matter because they went for manual braking... but the antiskid is BSCU controlled no? And it controls the selection of green and yellow HYD ? Both BSCU failures wouldn't yield the chime on phase 8, but could it yield in a screw up in the brake normal selection valve and loss of antiskid?
MASTER CAUTION?
Lemurian... if they did hit the runway at 300m, they reach "70KIAS" at 1340m... 70 + 10 = 80KIAS... and about 4 secs until the chime.
at 3.4m/s/s, if the constant decel continued, then during that 4secs they went down to 25.3m/s or abou 52kts GNDSPD and covered about 128.5m
1340 + 128.5 = 1468.5
And then 4.5 secs later (when all the loud noises started), they went a further 114m assuming no decel... this would give 1582m... from "FORTY"
If the deceleration was correct and continued all the way... could the have stopped from 52kts within say 130m? Well, they could have stopped in 80m, or, if they had 1/2 the decel after the chime, they would stop within 96m.
Let's go and work this backwards...
from runway excursion to the chime = 114m
"70" call to chime = 128.5m
Reversers deployed to "70" = 586m
T/D to reversers deploying = 454m
So how much did they have on touchdown? Add them all up and it says 1282m
There's 1650m from threshold to threshold... assuming 300m threshold to t/d, they should have touched down with 1350m to go... they should have been able to stop... even if the decel halved after the chime even with only 1282m to go on t/d... they should have been able to stop with even 1/10th the deceleration after the chime (ie: only 0.34m/s/s)...
From all these extrapolations and guessculations, I would think that it is very difficult to guess at this time that other than anti skid failure/total brake failure this landing would have ended up where it is. Had they landed faster, there's would have been greater deceleration to reach that "70" call out at the given time, hence would not have made much difference since they would have the same or more distance to stop from 80kt GNDSPD until going off the end.
OK, enough of my rubbish for tonight...
Decel Light comes on when actual deceleration is 80% of the selected rate.
"On slippery runway, the predetermined deceleration may not be reached due to antiskid operation. In this case, DECEL light will not illuminate. This does not mean that A/B is not working."
But, they went on manual braking anyways... so we're down to the antiskid?
Antiskid should operate until down to 20kts GNDSPD.
I'm quite interested in that single chime about 4 secs after the 70 kts call. I assume the 70kts was IAS, and that the aircraft was about 80kts gndspeed given the 10kt tailwind, and higher GND SPD with the altitude, hence it is either in phase 8 or 9 of the flight.
On those 2 phases, on braking, the chime can come from hot brakes, A/B fault when armed, or HYD SEL FAULT (failure of brake normal selector valve or NWS selector valve in open position)... the only one extending to phase 9 is A/B fault when armed.
Now a BSCU fault would not yield the chime, the A/B fault shouldn't matter because they went for manual braking... but the antiskid is BSCU controlled no? And it controls the selection of green and yellow HYD ? Both BSCU failures wouldn't yield the chime on phase 8, but could it yield in a screw up in the brake normal selection valve and loss of antiskid?
And finally that the Captain said - his last words, as it turned out - "Cancel, cancel the........"
Lemurian... if they did hit the runway at 300m, they reach "70KIAS" at 1340m... 70 + 10 = 80KIAS... and about 4 secs until the chime.
at 3.4m/s/s, if the constant decel continued, then during that 4secs they went down to 25.3m/s or abou 52kts GNDSPD and covered about 128.5m
1340 + 128.5 = 1468.5
And then 4.5 secs later (when all the loud noises started), they went a further 114m assuming no decel... this would give 1582m... from "FORTY"
If the deceleration was correct and continued all the way... could the have stopped from 52kts within say 130m? Well, they could have stopped in 80m, or, if they had 1/2 the decel after the chime, they would stop within 96m.
Let's go and work this backwards...
from runway excursion to the chime = 114m
"70" call to chime = 128.5m
Reversers deployed to "70" = 586m
T/D to reversers deploying = 454m
So how much did they have on touchdown? Add them all up and it says 1282m
There's 1650m from threshold to threshold... assuming 300m threshold to t/d, they should have touched down with 1350m to go... they should have been able to stop... even if the decel halved after the chime even with only 1282m to go on t/d... they should have been able to stop with even 1/10th the deceleration after the chime (ie: only 0.34m/s/s)...
From all these extrapolations and guessculations, I would think that it is very difficult to guess at this time that other than anti skid failure/total brake failure this landing would have ended up where it is. Had they landed faster, there's would have been greater deceleration to reach that "70" call out at the given time, hence would not have made much difference since they would have the same or more distance to stop from 80kt GNDSPD until going off the end.
OK, enough of my rubbish for tonight...
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A320 LOSS OF BRAKING NNC
REV.............................MAX
BRAKE PEDALS...............RELEASE
A/SKID & NWSTRG..........OFF
BRAKE PEDALS...............PRESS
MAX BRAKE PR...............1000psi
If still no braking:
PARKING BRAKE..............SHORT & SUCCESSIVE APPLICATIONS
This was introduced following the Ibiza incident 1998.Failure of normal brakes due logic disagreement in both BSCU channels(computers!)Alternate brakes fail because of frozen valve.Crew unaware of the status of their aircraft as they landed!!
ECAM message inhibited on landing(Safety recommendation V-"It is therefore recommended to Airbus Industrie that warning messages about any change in the status of the braking system during the landing phase be immediately communicated to the crew via the ECAM"
Concerning the Cardiff incident 2003,the pilot did not in fact forget the drill as Lemurian asserts.He asked for the ASKID/NWSTRG switch to be placed off during the rollout when he realized deceleration was abnormal.Again,the safety recommendation points its finger directly at the design when it says
"It is recommended that Airbus improve the automated warnings to flightcrews concerning the loss of braking system effectiveness folllowing touchdown or rejected takeoff"(2004-82)
Pilots must know the condition of their aircraft at all times.The relay of the information from machine to man must be unambiguous and immediate.This is super-critical during takeoff/landing phase.
How this relates to the TACA crash,only time will tell.But all the runway excursions there have been Airbus.Unless you wear blinkers,it tells a story.
REV.............................MAX
BRAKE PEDALS...............RELEASE
A/SKID & NWSTRG..........OFF
BRAKE PEDALS...............PRESS
MAX BRAKE PR...............1000psi
If still no braking:
PARKING BRAKE..............SHORT & SUCCESSIVE APPLICATIONS
This was introduced following the Ibiza incident 1998.Failure of normal brakes due logic disagreement in both BSCU channels(computers!)Alternate brakes fail because of frozen valve.Crew unaware of the status of their aircraft as they landed!!
ECAM message inhibited on landing(Safety recommendation V-"It is therefore recommended to Airbus Industrie that warning messages about any change in the status of the braking system during the landing phase be immediately communicated to the crew via the ECAM"
Concerning the Cardiff incident 2003,the pilot did not in fact forget the drill as Lemurian asserts.He asked for the ASKID/NWSTRG switch to be placed off during the rollout when he realized deceleration was abnormal.Again,the safety recommendation points its finger directly at the design when it says
"It is recommended that Airbus improve the automated warnings to flightcrews concerning the loss of braking system effectiveness folllowing touchdown or rejected takeoff"(2004-82)
Pilots must know the condition of their aircraft at all times.The relay of the information from machine to man must be unambiguous and immediate.This is super-critical during takeoff/landing phase.
How this relates to the TACA crash,only time will tell.But all the runway excursions there have been Airbus.Unless you wear blinkers,it tells a story.
Last edited by Rananim; 9th Jul 2008 at 00:36.
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PK-KAR,
Yes, but there are so many messages -not related to braking- that could re-appear on phase 8.
Your guess is as good as mine. Where our assumptions match is that they had a very narrow margin of error...But still they should have stopped inside the runway distance...but did not.
safetypee,
I have enquired and I don't know of an airline with a *decel* call-out based on the PFD speed trend.
This level ( remember i was talking of a .35G deceleration) should be felt, physically.
I would agree with you on principle and for low values of negative G forces, but not this high. The figures I gathered showed up to the 70 kt call a very healthy, effective braking. Hell broke loose one second later.
I agree. Pilots should be practicing manual braking, trying for a close turn-off...etc...but that crew had a good experience of short runway ops, so they would have known.
One question remains, though : As the crew was apparently treating this landing as routine, why did they realise so late that they were running out of runway ? Is there a problem seeing the runway end ?
On those 2 phases, on braking, the chime can come from hot brakes, A/B fault when armed, or HYD SEL FAULT
So how much did they have on touchdown? Add them all up and it says 1282m
There's 1650m from threshold to threshold... assuming 300m threshold to t/d, they should have touched down with 1350m to go... they should have been able to stop... even if the decel halved after the chime even with only 1282m to go on t/d... they should have been able to stop with even 1/10th the deceleration after the chime (ie: only 0.34m/s/s)...
There's 1650m from threshold to threshold... assuming 300m threshold to t/d, they should have touched down with 1350m to go... they should have been able to stop... even if the decel halved after the chime even with only 1282m to go on t/d... they should have been able to stop with even 1/10th the deceleration after the chime (ie: only 0.34m/s/s)...
safetypee,
Alternatively, if the SOP was to call ‘decel’ based on the PFD speed trend, then the conclusion is that aircraft was decelerating.
I disagree with the assertion that “The kind of deceleration we are talking about here will be felt, …”
If the runway condition involved low friction, then the majority of the deceleration would come from reverse. After cancelling reverse, the relative ineffectiveness of the brakes could be perceived as a failure.
Problems in this area stem from training / experience, where IMHO crews are not familiar with maximum manual braking on a wet runway; auto-brake removes an important cue, and with everyday use of reverse, it masks the brake contribution to the total deceleration.
One question remains, though : As the crew was apparently treating this landing as routine, why did they realise so late that they were running out of runway ? Is there a problem seeing the runway end ?
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A bit more information from that Avherald site:-
"The Civil Aviation Authority of El Salvador, responsible to perform the investigation into the accident of TACA flight 390, does not endorse the reports of human error, that were published in Honduras yesterday also producing "transcripts".
"El Salvador does not yet rule out any cause of the accident including human error and continues to say, that the investigation will take about a year until reaching conclusions."
Crash: TACA A320 at Tegucigalpa on May 30th 2008, overran runway and crashed into embankment
On the face of it that makes no sense. The First Officer survived the crash, the FDR and CVR have been decoded, the aeroplane didn't burn - they must already have a pretty good idea about the 'probable causes.' And if, as one begins to suspect, they have direct and current safety implications, they have no business withholding them for 'about a year.'
The story continues:-
"A campaign to reopen Toncontin for International Traffic including category C and D aircraft was launched in Honduras with the support of the Mayor of Tegucigalpa, hoping to be able to overturn the President's decision to close the airport."
That in turn leads on from an earlier reported rumour on the same site that the ICAO had checked the runway friction etc. and reckoned that the airport could still accept larger aeroplanes (except for the A320):-
"Rumours out of Honduras earlier today had suggested, that the ICAO delegation recommended to reopen the airport with some modifications, which had already been put in force by airlines operating into Toncontin anyway. According to those rumours the only major change would have been to recommend operating the A319 into Toncontin instead of the A320."
All the signs are that there's a 'Class A' cover-up in progress......
"The Civil Aviation Authority of El Salvador, responsible to perform the investigation into the accident of TACA flight 390, does not endorse the reports of human error, that were published in Honduras yesterday also producing "transcripts".
"El Salvador does not yet rule out any cause of the accident including human error and continues to say, that the investigation will take about a year until reaching conclusions."
Crash: TACA A320 at Tegucigalpa on May 30th 2008, overran runway and crashed into embankment
On the face of it that makes no sense. The First Officer survived the crash, the FDR and CVR have been decoded, the aeroplane didn't burn - they must already have a pretty good idea about the 'probable causes.' And if, as one begins to suspect, they have direct and current safety implications, they have no business withholding them for 'about a year.'
The story continues:-
"A campaign to reopen Toncontin for International Traffic including category C and D aircraft was launched in Honduras with the support of the Mayor of Tegucigalpa, hoping to be able to overturn the President's decision to close the airport."
That in turn leads on from an earlier reported rumour on the same site that the ICAO had checked the runway friction etc. and reckoned that the airport could still accept larger aeroplanes (except for the A320):-
"Rumours out of Honduras earlier today had suggested, that the ICAO delegation recommended to reopen the airport with some modifications, which had already been put in force by airlines operating into Toncontin anyway. According to those rumours the only major change would have been to recommend operating the A319 into Toncontin instead of the A320."
All the signs are that there's a 'Class A' cover-up in progress......
PK-KAR, “ …it is very difficult to guess …”
It may be easier to guess, or better consider for the purpose of debate, that full braking, either auto-brake or manual brake was not applied for at lest some part of the landing roll out.
Re; “ … if the constant decal … ”; this is an ambitious assumption.
Deceleration during landing is rarely constant; see CS 25 Large Aircraft / Amendment 4 pages 2-B-36, 37 - diagrams of anti skid response characteristics. Just because auto-brake is set to a desired deceleration value, does not mean that this value is achieved or maintained; it only a target.
“(f) The anti-skid function must be able to reduce braking for a wheel/tyre that is going into a skid, whether the braking level is commanded by the pilot or an auto-brake system if installed.” (CS 25 2-D-46)
It may be easier to guess, or better consider for the purpose of debate, that full braking, either auto-brake or manual brake was not applied for at lest some part of the landing roll out.
Re; “ … if the constant decal … ”; this is an ambitious assumption.
Deceleration during landing is rarely constant; see CS 25 Large Aircraft / Amendment 4 pages 2-B-36, 37 - diagrams of anti skid response characteristics. Just because auto-brake is set to a desired deceleration value, does not mean that this value is achieved or maintained; it only a target.
“(f) The anti-skid function must be able to reduce braking for a wheel/tyre that is going into a skid, whether the braking level is commanded by the pilot or an auto-brake system if installed.” (CS 25 2-D-46)
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Speed Trend Arrow and "Decel"-Call
Lemurian,
Thanks a lot for your input and your educated guesses about landing distances and stopping margins. Very intriguing, I'm curious to see how this one comes out in the end.
Strictly based on the PFD speed trend is perhaps saying too much, but EASA published a temporary revision to the Airbus A320 family FCOM in SIN 2008-10, which can be found on this page.
NVPilot, yes, quite a recent revision to the procedure, that may not yet have been incorporated into all operators' manuals.
There may or may not be a similar revision for Latin American operators, but the cited revision states in the LANDING SOP:
So the Decel call is based on, in this order:
The revision also includes a reversionary procedure for "No Spoilers", which was sorely missing from the FCOM, namely to ...
Together with the following ...
... this marks it clearly as a consequence of the runway overrun accident of a TAM A320 at Sao Paulo Congonhas in July 2007.
Common to both accidents may be a failure to assess deceleration correctly in a critical phase (at Congonhas: after touchdown, at Toncontin: after "70kts").
Bernd
Thanks a lot for your input and your educated guesses about landing distances and stopping margins. Very intriguing, I'm curious to see how this one comes out in the end.
I have enquired and I don't know of an airline with a *decel* call-out based on the PFD speed trend.
NVPilot, yes, quite a recent revision to the procedure, that may not yet have been incorporated into all operators' manuals.
There may or may not be a similar revision for Latin American operators, but the cited revision states in the LANDING SOP:
Originally Posted by EASA Safety Information Notice 2008-10
[...]
DECELERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . CHECK/ANNOUNCE
The deceleration is felt by the flight crew, and confirmed by the speed trend on the PFD.
The deceleration may also be confirmed by the DECEL light (if autobrake is on).
[...]
DECELERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . CHECK/ANNOUNCE
The deceleration is felt by the flight crew, and confirmed by the speed trend on the PFD.
The deceleration may also be confirmed by the DECEL light (if autobrake is on).
[...]
- Seat-of-the-pants
- Speed Trend Arrow on PFD
- DECEL light
The revision also includes a reversionary procedure for "No Spoilers", which was sorely missing from the FCOM, namely to ...
- Verify and confirm that both thrust levers are set to IDLE or REV detent.
[...]
[...]
Note: If one or more thrust levers remain above the IDLE detent, ground spoilers extension is inhibited.
... this marks it clearly as a consequence of the runway overrun accident of a TAM A320 at Sao Paulo Congonhas in July 2007.
Common to both accidents may be a failure to assess deceleration correctly in a critical phase (at Congonhas: after touchdown, at Toncontin: after "70kts").
Bernd
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Lemurian,
Re the assertation that no airline can be found that uses the speed trend to deduce "DECEL", please see the latest FCOM 3 SOPs from Airbus that (finally after all these years) shows that they have woken up to what the operators have been telling them for years - that calling DECEL or NO DECEL based on the green light in the Autobrake switch is ridiculous.
The latest SOP states that DECEL should be called when it is felt by the crew and that it can be called also for the DECEL light and the speed trend arrow.
For years I have been advocating that what Airbus taught in their TRTOs on this issue was rubbish. They even taught pilots to call "NO DECEL" if no green light!
At least they know now how important it was all along. Another example of the "Not invented here" syndrome so beloved of many in TLS? If the "B company" did it then it couldn't be right for the "A company". Pathetic - but what a shame because they actually build very good aircraft.
Re the assertation that no airline can be found that uses the speed trend to deduce "DECEL", please see the latest FCOM 3 SOPs from Airbus that (finally after all these years) shows that they have woken up to what the operators have been telling them for years - that calling DECEL or NO DECEL based on the green light in the Autobrake switch is ridiculous.
The latest SOP states that DECEL should be called when it is felt by the crew and that it can be called also for the DECEL light and the speed trend arrow.
For years I have been advocating that what Airbus taught in their TRTOs on this issue was rubbish. They even taught pilots to call "NO DECEL" if no green light!
At least they know now how important it was all along. Another example of the "Not invented here" syndrome so beloved of many in TLS? If the "B company" did it then it couldn't be right for the "A company". Pathetic - but what a shame because they actually build very good aircraft.
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Sidstar,
Re the assertation that no airline can be found that uses the speed trend to deduce "DECEL", please see the latest FCOM 3 SOPs from Airbus
This hasn't reached my airline books yet.
See also what Bernd said :
So the Decel call is based on, in this order:
Seat-of-the-pants
Speed Trend Arrow on PFD
DECEL light
Seat-of-the-pants
Speed Trend Arrow on PFD
DECEL light
Moreover, when you say :
They even taught pilots to call "NO DECEL" if no green light!
I wonder.
On the other hand, I would agree with your :
Another example of the "Not invented here" syndrome so beloved of many in TLS? If the "B company" did it then it couldn't be right for the "A company". Pathetic
But this discussion has no place here, I just wish that both manufacturers start giving us - pilots - back some sort of standardisation. Flight safety would benefit. Some airlines have a hell of a job trying for a fleet-wide set of SOPs and it's no joke. I know for instance that AF is using some dumbed-down procedures on their Airbus fleet in order to conform to the airplane utilisation on the Boeing fleet.
The jury is still out on this one.
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09/07/2008
TACA admits human error
TACA admitted that the accident of one of its aircraft, which crashed last May 30 at Toncontín International Airport in the capital of this country, was due to an error of the pilot of the ship, Cesare D'Antonio, confirmed an AP agency report.
"The pilots are human beings like us ... and comments between them occurred in the cabin of an aircraft in a natural way," TACA general manager told the local radio HRN of TAC in Honduras, Armando Fúnez. "The investigation of the case is advanced at 70%." He recognized as true a report published by local newspapers on the content of the "black box" of the fateful TACA flight 390, which highlights the conversation between D'Antonio and Toncontin control tower.
"That's part of the investigation (the accident), but there will be a report at the end," he added.
Shortly before the crash, D'Antonio, who died that day, tried to communicate with the control tower of El Salvador to ask permission to deviate to San Pedro Sula, about 180 kilometres north of Tegucigalpa, or return to their country.
"We have tail wind. The clouds are very low," the pilot was heard in the recording. His last readable word is "pu ....".
In the chat, air traffic controllers told the pilot that there was a visibility of only two kilometres, when required is five in the air terminal, and that the runway was wet and cloudy skies over the capital. For these reasons, he was urged to land in the north end of Toncontín. The pilot, however, requested otherwise and, to his insistence, the tower authorized him to land in the south of the runway.
With 124 passengers and six crew members, the Airbus A320 overran the runway, collapsed trees in its path, broke a fence of steel wire, slipped by a 20 meter hollow north of Toncontín and remained in the hillside . It was removed 12 days later.
Dialogue is disclosed in Honduras since Thursday evening on television and local newspapers, which did not explain how it was obtained.
"The black boxes of the airplane are already in our possession," said on Thursday in a press conference the director general of Civil Aviation, Guillermo Seamann. It was recovered the day after the accident to determine the causes of it, which killed five people and left 65 injured.
According to the U.S. embassy in Tegucigalpa, "the results of the information obtained from the data and voice recorders of TACA flight 390 were handed over to the Civil Aeronautics Board by the National Transportation Safety Board (NTSB, por sus siglas in English) ".
Honduras sent in early June the black box to Washington so that the NTSB would review. The investigation of the accident is headed by the Civil Aviation Authority of El Salvador, by delegation from Honduras, and could last more than a year. Experts participating in the case are from the four countries involved: Honduras, where the accident occurred; El Salvador which is the headquarters of TACA; France, where the plane was manufactured, and the United States because the two turbines were manufactured there.
"We believe that at this time, while the investigation has not been completed, it is unwise to comment on the data (black box) or make them available to the public, because they are part of an extensive investigation and, hence, are inconclusive," said the U.S. embassy in a statement.
It also noted that at the request of France, investigators will meet in the third week of July at the premises of the NTSB in Washington "to analyse the data compilation to date and coordinate the next steps forward".
TACA admits human error
TACA admitted that the accident of one of its aircraft, which crashed last May 30 at Toncontín International Airport in the capital of this country, was due to an error of the pilot of the ship, Cesare D'Antonio, confirmed an AP agency report.
"The pilots are human beings like us ... and comments between them occurred in the cabin of an aircraft in a natural way," TACA general manager told the local radio HRN of TAC in Honduras, Armando Fúnez. "The investigation of the case is advanced at 70%." He recognized as true a report published by local newspapers on the content of the "black box" of the fateful TACA flight 390, which highlights the conversation between D'Antonio and Toncontin control tower.
"That's part of the investigation (the accident), but there will be a report at the end," he added.
Shortly before the crash, D'Antonio, who died that day, tried to communicate with the control tower of El Salvador to ask permission to deviate to San Pedro Sula, about 180 kilometres north of Tegucigalpa, or return to their country.
"We have tail wind. The clouds are very low," the pilot was heard in the recording. His last readable word is "pu ....".
In the chat, air traffic controllers told the pilot that there was a visibility of only two kilometres, when required is five in the air terminal, and that the runway was wet and cloudy skies over the capital. For these reasons, he was urged to land in the north end of Toncontín. The pilot, however, requested otherwise and, to his insistence, the tower authorized him to land in the south of the runway.
With 124 passengers and six crew members, the Airbus A320 overran the runway, collapsed trees in its path, broke a fence of steel wire, slipped by a 20 meter hollow north of Toncontín and remained in the hillside . It was removed 12 days later.
Dialogue is disclosed in Honduras since Thursday evening on television and local newspapers, which did not explain how it was obtained.
"The black boxes of the airplane are already in our possession," said on Thursday in a press conference the director general of Civil Aviation, Guillermo Seamann. It was recovered the day after the accident to determine the causes of it, which killed five people and left 65 injured.
According to the U.S. embassy in Tegucigalpa, "the results of the information obtained from the data and voice recorders of TACA flight 390 were handed over to the Civil Aeronautics Board by the National Transportation Safety Board (NTSB, por sus siglas in English) ".
Honduras sent in early June the black box to Washington so that the NTSB would review. The investigation of the accident is headed by the Civil Aviation Authority of El Salvador, by delegation from Honduras, and could last more than a year. Experts participating in the case are from the four countries involved: Honduras, where the accident occurred; El Salvador which is the headquarters of TACA; France, where the plane was manufactured, and the United States because the two turbines were manufactured there.
"We believe that at this time, while the investigation has not been completed, it is unwise to comment on the data (black box) or make them available to the public, because they are part of an extensive investigation and, hence, are inconclusive," said the U.S. embassy in a statement.
It also noted that at the request of France, investigators will meet in the third week of July at the premises of the NTSB in Washington "to analyse the data compilation to date and coordinate the next steps forward".
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And now THIS story says that Toncontin has re-opened to 'commercial jets':-
"The Honduran capital's Toncontin International Airport reopened to commercial jets on Saturday, six weeks after an airliner overshot the runway — killing five and injuring 68.
"The airport was closed after a Grupo Taca jet carrying 124 people ran off the runway and slammed into a busy street on May 30. Among the dead were two people on the ground. The injured included seven Americans, two Canadians and four Europeans.
"After the crash, the airport only allowed planes carrying 42 people or less because of safety concerns. Larger flights were rerouted to San Pedro Sula, 112 miles north of the capital, Tegucigalpa.
"American and Continental Airlines, Copa of Panama and El Salvador's Taca said they would start sending flights to the capital sometime next week, once they reprogram their routes."
Honduran airport reopens to jets 6 weeks after plane overshoots runway - International Herald Tribune
Begins to look like an unscrupulous public relations approach that I've occasionally seen used in some fields, but not previously in connection with fatal aircraft accidents:-
1. At first, say nothing.
2. Then leak a small amount of information (in this case the edited transcript) pointing to a single cause (in this case 'pilot error').
3. Then say nothing more (except denying that you said anything at all) for a good long time. Thus ensuring that, by the time the investigation report finally comes out, it'll be 'old news,' and most people will say, "Oh yes, Toncontin - wasn't that the crash where the pilot used the wrong runway or something?"
"The Honduran capital's Toncontin International Airport reopened to commercial jets on Saturday, six weeks after an airliner overshot the runway — killing five and injuring 68.
"The airport was closed after a Grupo Taca jet carrying 124 people ran off the runway and slammed into a busy street on May 30. Among the dead were two people on the ground. The injured included seven Americans, two Canadians and four Europeans.
"After the crash, the airport only allowed planes carrying 42 people or less because of safety concerns. Larger flights were rerouted to San Pedro Sula, 112 miles north of the capital, Tegucigalpa.
"American and Continental Airlines, Copa of Panama and El Salvador's Taca said they would start sending flights to the capital sometime next week, once they reprogram their routes."
Honduran airport reopens to jets 6 weeks after plane overshoots runway - International Herald Tribune
Begins to look like an unscrupulous public relations approach that I've occasionally seen used in some fields, but not previously in connection with fatal aircraft accidents:-
1. At first, say nothing.
2. Then leak a small amount of information (in this case the edited transcript) pointing to a single cause (in this case 'pilot error').
3. Then say nothing more (except denying that you said anything at all) for a good long time. Thus ensuring that, by the time the investigation report finally comes out, it'll be 'old news,' and most people will say, "Oh yes, Toncontin - wasn't that the crash where the pilot used the wrong runway or something?"
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To newly qualified crews: There is always a bit of the "need to get in" factor that all pilots have, experienced pilots realize that there is no big reward after you land if you bent some of the rules, there is no good feeling about it when you review it in your mind, follow SOP and company guidance for many years of safe operation like Bubbers.
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I just checked my airline's schedule and we start normal B757 service Aug 1 to TGU. Great news. We may have helped here to put the pressure on the pres. to reopen. next year, if they get the military base north of Tegucigalpa ready they plan on moving all commercial jet operations there. If I was still flying that would make me sad because flying into TGU was really a lot of fun.