The recent revision to the Airbus procedures during landing aims to improve crew awareness of spoiler / reverser deployment and of the aircraft’s deceleration. The change resulted from a previous accident where apparently, reverse was not engaged and the spoilers did not deploy, which resulted in the loss of auto brake.
The effectiveness of the new procedure in maximizing landing safety might depend on exactly how the procedures are implemented. IMHO the CHECK/ANNOUNCE deployment of the spoilers and reverse might be interpreted in two ways:-
The other action is to CHECK/ANNOUNCE that deceleration is felt, confirmed by the PFD speed trend, and the DECEL light if auto brake is used. This procedure is more complicated. Accepting that calling the failure is the better method, this then questions what constitutes a failure – low deceleration - what is a low value on the PFD speed trend. For auto brakes, the DECEL light on/off clearly identifies status, albeit inconsistent, depending on the level of braking selected. For manual braking, crews should have a ‘calibration’ deceleration from normal operations, but detecting the spoiler / reverse non deployment is a comparative process that is assumed to be unambiguous. This might be a reasonable assumption for reverse operation, but for spoiler only, on a low friction runway then there could be some doubt. However, in the latter instance, calling a false failure may not be a problem as it should invoke alternative action, e.g. apply maximum braking / select max reverse. There could also be a problem identifying low deceleration where there is a spoiler or reverse failure; the only remaining option is selection/reselection / maximum braking, which in limiting conditions might not be sufficient to stop the aircraft in the remaining distance. However, IIRC the certification aspects of spoiler /reverse failures are such that these failures are extremely unlikely. This scenario identifies a weakness in the new procedure as there are apparently no instructions of what action crews should take in the event of the a ‘negative’ response to any of the checks; the systems aspects might be covered elsewhere in the FCOM, but what to do crews do after identifying low deceleration? This weakness also identifies the need for crews to think ahead – ‘what if’. E.g. when landing in limiting conditions – tailwind, low friction runway, when the reverse / spoiler / max brake options are required, there would few if any alternative actions in the event of a failure. These situations do occasionally arise in operations and SOPs should be provided; crews require an alternative course of action - perhaps an ‘undo’ option. In this accident, there is mounting evidence that a situation as above was encountered and as stated by Lemaurin “ … the crew was apparently treating this landing as routine”; which was an initiating human activity contributing to the cause. The lack of selecting Max auto brake may be an indicator of the crew’s failure to perceive the threats in this landing. If the landing briefing had considered the non normal aspects, then the limiting scenario might not have been encountered (avoiding short wet runways and tail winds), or mitigating action such a GA if the touchdown was not within specified distances or at an acceptable speed. So ? … SOPs are difficult to formulate for every scenario, each activity should be executable (defined limits), and all follow-on action should be considered. Would the new procedures have helped in this accident, or was it a scenario to be avoided? |
Originally Posted by alf5071h
The lack of selecting Max auto brake may be an indicator of the crew’s failure to perceive the threats in this landing.
Is there anything in the earlier conversation that would amount to an approach briefing - give us flap settings, brake settings, etc.? |
Autobrake and Deceleration.
Originally Posted by alf5071h
The recent revision to the Airbus procedures during landing aims to improve crew awareness of spoiler / reverser deployment and of the aircraft’s deceleration. The change resulted from a previous accident where apparently, reverse was not engaged and the spoilers did not deploy, which resulted in the loss of auto brake.
In the specific accident that almost certainly prompted this revision, reverse was selected on one engine, but more importantly, the other thrust lever was apparently left at the CLIMB detent. Here's the relevant PPRuNe thread. For auto brakes, the DECEL light on/off clearly identifies status, albeit inconsistent, depending on the level of braking selected. One problem with the autobrake is that there is absolutely no indication of its operational status. Only of arming status and achieved deceleration threshold, and, on the ECAM, Anti-Skid-Operation. This still contrasts with the FCOM, which states "Monitor the autobrake, if it is on." There is no way to monitor autobrake operation, except indirectly. [...] However, IIRC the certification aspects of spoiler /reverse failures are such that these failures are extremely unlikely. Reversers are a different story. Reverse thrust is usually considered a bonus feature, and not required. Thrust reversers are, compared to Spoilers, very unreliable, and dispatch with deactivated reversers is permitted and common. In particular, the calculations for stopping distances for rejected takeoffs do not take reverse thrust into account. This scenario identifies a weakness in the new procedure as there are apparently no instructions of what action crews should take in the event of the a ‘negative’ response to any of the checks; the systems aspects might be covered elsewhere in the FCOM This weakness also identifies the need for crews to think ahead – ‘what if’. E.g. when landing in limiting conditions – tailwind, low friction runway, when the reverse / spoiler / max brake options are required, there would few if any alternative actions in the event of a failure. These situations do occasionally arise in operations and SOPs should be provided; crews require an alternative course of action - perhaps an ‘undo’ option. You mean, as in a flight simulator? "Oops, that wasn't quite right, let's forget we ever did it ..."? But this revision is about what we call "reversionary procedures.", i. e. what to do if things do not do what we expected them to do. The lack of selecting Max auto brake may be an indicator of the crew’s failure to perceive the threats in this landing. Would the new procedures have helped in this accident, or was it a scenario to be avoided? but what to do crews do after identifying low deceleration? Bernd |
bsieker
One problem with the autobrake is that there is absolutely no indication of its operational status. Only of arming status and achieved deceleration threshold, and, on the ECAM, Anti-Skid-Operation. BUT, as you said, the real operational status is not displayed. ( I wonder how it can be achieved, though...) alf5071h If the landing briefing had considered the non normal aspects, then the limiting scenario might not have been encountered (avoiding short wet runways and tail winds), or mitigating action such a GA if the touchdown was not within specified distances or at an acceptable speed. From the guessculations I made, it is quite obvious that they had a normal-ish touch-down (otherwise they would have exited he runway faster with more tragic consequences). New points : From the latest transcript, there is a puzzling detail : Before the 40 ft rad-alt call-out, the Captain was in charge of all communications... and then all the SOPs call-outs were made by the F/O... Who was flying the airplane in both stages ? According to SOPs, the captain did the landing. When did control transfer occur ? The "quitame..." call : The meaning of *quitar* are : to remove /to rub off / to take away / to eliminate or cancel /to doff.../ to rid off... So far, we just assumed that it was "cancel(...) for me", meaning a procedural action. What if any other meaning is considered ? Alf5071h's remark on Max auto brake made me research the deceleration values of an airplane with that feature. On the 737 NG, that max setting corresponds to a deceleration of .43G above 80kt and .37G below. So. to put their braking effectiveness into perspective - .35G-, they achieved a deceleration just about comparable with Max and far superior to level 3 setting -.224G- of a 737NG. |
alf5071h;
It would be simpler,faster, intuitive and more reliable to allow pilots to manually select the spoilers if and when required. The system was probably designed the way it is because the aircraft cannot tolerate spoilers inflight in config.full. A secondary factor may be the European infatuation with taking a simple concept and sending it to the department of obfuscation for a maximum rework. When I worked in Europe I was always amazed at how well they do this. Perhaps it is a "make work" concept held over from past eras of high unemployment. |
I have been thinking about it for some days now, and relates to the CVR transcript appearing on the media.
This is what is shown in spanish: 15:33:54.3 - (Operaciones) TACA TRES NUEVE CERO, operaciones, buenos días 15:34:14.3 - (Piloto) Vah, si frustramos en ésta 15:34:17.1 - (Piloto) Nos vamos al VOR holdeamos, 15:34:18.8 - (Piloto) Preguntamos a operaciones que tienen hasta el combustible 15:34:21.0 - (Piloto) Qué tenemos si nos vamos para San Pedro (Algunos segundos después) 15:36:23.6 - (Piloto) si quiere pruebe operaciones otra vez... dígale que estamos haciendo el segundo (intento)... que pregunte a El Salvador que queremos hacer si fallamos en esta An this would be in english according to my understanding (consider this is all during the go around and new approach, a time to do vital cockpit decisions): 15:33:54.3 - (Operations) TACA THREE NINE CERO, operations, good morning 15:34:14.3 - (Pilot) Bahh, if we go around in this one 15:34:17.1 - (Pilot) We go to the VOR and hold, 15:34:18.8 - (Pilot) Ask operations that even has the fuel 15:34:21.0 - (Pilot) We have if we go to San Pedro (Some seconds later) 15:36:23.6 - (Pilot) if you want try operations again...... tell them we are doing the second (try).... and ask to El Salvador what we want to do if we fail in this one Sorry guys, but I am a little confused: Who makes the decision to go around? Is it us on the cockpit or someone else on a desk down in El Salvador? Were they much more worried that they HAD to land even with a 10 knot tailwind? |
Lemurian:
The "quitame..." call : The meaning of *quitar* are : to remove /to rub off / to take away / to eliminate or cancel /to doff.../ to rid off... So far, we just assumed that it was "cancel(...) for me", meaning a procedural action. What if any other meaning is considered ? "El" means the Capt is referring to something (not plural) with a masculin name in spanish even though they can use the original name in the complete sentence (like "el piloto automatico" or "el Auto Pilot") as opposed to something using a feminin reference ("la pista / la frequencia" - the runway / the frequency). This little detail could cut in half all the possibilities mentioned here. A spanish speaking (airbus) pilot would understand more easely what could prompt that call from the Capt at that point in time. Usually "Quiteme" means switch that off for me. As an aside, I've also noted that the Capt was really p1ssed about ATC and how they were having a lot of work right in the middle of the approach phase due to change of runway in short notice; hijoeputa (SOB) is not a very friendly name. 15:20:16.8 - (Piloto) Ya sabía Yo [I knew it!] 15:20:18.7 - (Piloto) Gran pendejo este hijoeputa, porque dijo primero la aproximación... [*lots of expeletives towards ATCer* ..., because he first told us the approach...] (...) 15:20:46.5 - (Piloto) Mas es lo que me hacen hacer trabajar de mas estos cerotes [But it's what these *very unpolite name* make me work more] Then he was complaining about how the clouds were too low (for comfort?) and then goes saying "thats why they pay us enough money just for having us make this sh1t happen". He was not very happy with the whole situation. 15:41:12.5 - (Piloto) Puta, pero es que está muy baja esta mierda hombre! 15:42:30.9 - (Piloto) Ves, para esto no nos pagan lo suficiente para andar inventando esta mierda... 15:42:39.2 - (copiloto) remove status? 15:42:40.2 - (Piloto) cómo? 15:42:40.9 - (copiloto) remove status? 15:42:41.4 - (Piloto) clear removed. 15:42:42.3 - (copiloto) sí. |
kwick,
Sorry guys, but I am a little confused: Who makes the decision to go around? Is it us on the cockpit or someone else on a desk down in El Salvador? Were they much more worried that they HAD to land even with a 10 knot tailwind? It's normal - and economical - practice : the decision still rests on the commander but he'd know the best place to be for his passengers. GDL, the F/O makes a call: Quote: 15:42:39.2 - (copiloto) remove status? 15:42:40.2 - (Piloto) cómo? 15:42:40.9 - (copiloto) remove status? 15:42:41.4 - (Piloto) clear removed. 15:42:42.3 - (copiloto) sí. What call was that. |
Tree
It would be simpler,faster, intuitive and more reliable to allow pilots to manually select the spoilers if and when required. The system was probably designed the way it is because the aircraft cannot tolerate spoilers inflight in config.full. A secondary factor may be the European infatuation with taking a simple concept and sending it to the department of obfuscation for a maximum rework. When I worked in Europe I was always amazed at how well they do this. Perhaps it is a "make work" concept held over from past eras of high unemployment. In terms of HF, it has been discovered that checking a system status is in general better than *operating* the system where the cross-check of the action fails : it's just human "I pulled the lever, therefore it's there..." when in reality it is not. |
Originally Posted by Tree
It would be simpler,faster, intuitive and more reliable to allow pilots to manually select the spoilers if and when required.
The system was probably designed the way it is because the aircraft cannot tolerate spoilers inflight in config.full. In the Speedbrakes function (which, true enough, is not recommended on A320 with flaps in Config FULL) only some of the surfaces extend a small portion of the maximum deflection. Speedbrakes can be used in any flight phase. Further, to prevent accidental Ground Spoiler deployment, there has to be a safeguard against deploying them in the air, or at other critical phases, such as during takeoff with takeoff thrust. Every airliner has such a safeguard, some mechanical, some by computer logic, or by a combination. Modern computerised aircraft, regardless of brand, tend to do it in computer logic. No one way is inherently more or less safe than the other. Now, as someone has put it nicely, "if it is unsafe to deploy the spoilers automatically, it is also unsafe to deploy them manually." Thus, if the conditions are right for spoiler deployment, and spoiler deployment has been requested (either by arming Ground Spoilers, touching down, and then retarding the thrust levers to idle, or by touching down, and then selecting reverse thrust), there's no reason for the spoilers not to be deployed. On the other hand, if the conditions are not right for the spoilers (either not on the ground, or substantial forward thrust), they should not be deployed, and not even be deployable manually, because someone might just do it inadvertently at the wrong moment. And if you think moving the wrong lever at the wrong time couldn't happen, just look at a recent report of an Airbus that landed with the parking brake on, most likely because the PNF, occupied with wind updates and radio traffic moved the parking brake lever instead of the flaps lever. It is conceivable that he might pull the speedbrake lever (ground spoilers!) instead of moving the flaps lever to CONF 1 for the approach. Bernd |
RWB, Max auto brake – my memory and thread-search fail me; as with evidence of briefing, not given facts. (Max auto brake unlikely, see other posts, but no evidence of a deliberate choice of manual braking).
Tree, “It would be simpler, faster, intuitive and more reliable to allow pilots to manually select the spoilers if and when required.” Yes, I agree, but in some types auto spoiler resulted from pilots forgetting to select them, e.g. BAe146 retrofit and Avro RJ. For vital actions where pilot error cannot be tolerated, then the system should be automated. But the level of automation should not require a check which could be subject to a further error; cf Lemaurin. We should not use the 'need for SOPs' to require a check. I don’t think that it is just Europe that has difficulty with words, procedures, etc. Perhaps the problem stems from the industry’s infatuation with ‘SOPs’. What is wrong having a highly trained professional to activate systems and judge deceleration … possibly the cost of training and inappropriate post accident action … or that humans are fallible? |
Bernd, thanks for the info on the DECEL light. If the light provides little information of relevance, then why not remove the need to check it. If the light is OFF, either because of a failure or a low friction runway, then the action would be the same – max manual brake.
There may be greater value in using manual braking more frequently to build up pilot’s experience base so that they might judge good or poor deceleration - "how much deceleration is enough?" Instead, users of auto brake seek the skill of monitoring an automatic system with an ‘irrelevant’ light based on a variable setting: – a generic problem of automation? "Undo"? No, not like the simulator. Like having a plan (briefing), and then judgement to revise or reject the plan as the situation develops; considering alternative courses of action and possible outcomes in various scenarios. Why "reversionary procedures" – the SOP fad again? There will not be a procedure for every situation, so pilots have to think; the industry should require operating standards / training standards which encourage/teach pilots to think. Re MAX Auto brake. So when landing in conditions where maximum braking is either prudent or essential, maximum manual braking is used? Is this an SOP? ;) Lemaurin, thanks for additions and the note on Max auto brake. The deceleration values are technicalities; when pilots apply manual braking what is the level of deceleration achieved …. it depends on the runway friction etc. I suggest that auto systems encourage pilots to believe that they will always get the required level of braking (deceleration), which provides a false sense of security, reducing the need for an assessment of what is actually happening. With the difficulties in assessing deceleration / braking, the assessment / decision is best done before landing – make the approach or change the plan. Thus, are auto-brake systems encouraging pilots to land in more marginal conditions than is sensible? Do pilots think (subconsciously) that they can ‘blame’ the autos if the landing goes wrong, thus avoid the manual option, even when the conditions indicate otherwise, or start with auto brake with a decision to change to manual based after an assessment (of deceleration) after touchdown? Too many opportunities for error. |
What infuriates me is that the authorities have access to the full CVR transcript, the FDR data, and the testimony of the First Officer. They must already KNOW, to quite fine limits, what probably happened.
Just tried to marshal all the information we have to hand (which isn’t much) and list some comments and possibilities. Comments, different interpretations, additional possibilities welcome. 15:43:46.8 [EGPWS] one thousand 15:43:47.6 [PIC] en ambar Possibilities – 1. the flight crew received a warning, which may have caused a ‘Cardiff-type’ incident (in which cycling the ‘Anti-Skid’ switch eliminated the warning, but ALSO cancelled the autobrake setting) OR 2. Any warning was about something else, OR 3. The pilot was only referring to the RA readout. Comment – the fact that this part of the recording is followed by a gap of over a minute, in which nothing AT ALL appears to have been said or heard, strains credibility to the limit. It is much more likely that other available material has been suppressed. 15:45:04.2 [EGPWS] Forty 15:45:04.9 [EGPWS] Thirty 15:45:05.7 [EGPWS] Twenty 15:45:06.2 [CAM] (sounds similar throttle movement) 15:45:06.2 [SV] Retard… retard 15:45:08.2 [EGPWS] FIVE 15:45:11.7 [CAM] (Sound similar touchdown & landing gear compression) Possibility – the ‘Five’ call may indicate a period of floating. Comment – otherwise appears to have been a normal touchdown. 15:45:12.1 [CAM] (sound similar throttle movement full reverse position) 15:45:13.3 [CAM] (sound increase in background noise) 15:45:13.4 [SIC] Spoiler Comment – that appears to have been a departure from the most prudent procedure, which I believe is to wait for the ‘spoilers’ call before deploying reverse thrust. The reason being that, especially on a short runway, deploying the reversers largely rules out the option of a go-around, because of the time needed to re-stow them. Doesn’t appear to be relevant, though, as the F/O confirmed the spoilers. Possibility – however, it has to be borne in mind that after the crash (see photo on first page of this thread) only two in-flight spoilers – the two furthest outboard of the ten panels – were deployed. So just possibly the F/O got it wrong. . 15:45:15.0 [CAM] (sound increase in background noise) 15:45:17.0 [SIC] rev(ersers) green Comment – normal procedure, I think. 15:45:18.9 [SIC] manual braking Possibilities – 1. The F/O was recommending manual braking because deceleration seemed inadequate, OR 2. The F/O was acknowledging the Captain having applied manual braking. 15:45:20.4 [SIC] decal Comment – F/O evidently felt that deceleration was now adequate (whether by ‘feel’ or by reference to the flight displays, we don’t know). 15:45:21.8 [CAM] (sound similar to engine spool up) 15:45:26.4 [CAM] (soun similar to engine spool down) Comment – consistent with an extra burst of reverse thrust – for about four seconds. 15:45:27.2 [SIC] SEVENTY Knots. Possibilities – 1. The F/O was just giving a routine notification that the speed was coming down towards the level at which reverse thrust would normally be discontinued, OR 2.The FO was warning the Captain that the speed still seemed too high – and maybe that there wasn’t an awful lot of runway left. Comment – the capital letters may just be a misprint, or they MAY indicate that the F/O was shouting. In other words, that this was the moment when he realised that they were in trouble. 15:45:28.3 [PIC] quíteme quíteme el….! 15:45:28.8 [CAM] (sound similar to throttle movement) Comment – thought at first that this might just have been the Captain telling the F/O to turn off the reverse thrust – but, of course, he would have had his hand on the throttles and would have done that himself. And the fact that he never finished the sentence suggests that he too was seriously worried by that time. Possibilities – 1. It was indeed a Cardiff’ situation, the Captain had realised that he didn’t have manual braking, and wanted the Anti-Skid turned off. 2. A BARE possibility that he wanted everything retracted and planned to try to go around (though, against that, he’d surely have said so?). 3. Almost ANYTHING else. 15:45:30.5 [CAM] (sound of click) 15:45:31.5 [CAM] (sounds of single chime) Comment – that was almost certainly a warning of some kind – but we have no way of knowing what it was. 15:45:33.0 [?] (sounds of inhale/exhale/breathing) 15:45:34.2 [CAM] (sound of thump/clunk) 15:45:34.8 [PIC] Puta. 15:45:35.2 [CAM] (sound of thump/clunk) 15:45:35.7 [CAM] (sound of thump/clunk) 15:45:36.0 [CAM] (very loud sounds begin, and continue to end of recording) 15:45:38.3 [CAM] (end of recording) No comment required, regrettably - except maybe RIP.... |
Alf,
The deceleration values are technicalities; when pilots apply manual braking what is the level of deceleration achieved …. it depends on the runway friction etc. I suggest that auto systems encourage pilots to believe that they will always get the required level of braking (deceleration), which provides a false sense of security, reducing the need for an assessment of what is actually happening. With the difficulties in assessing deceleration / braking, the assessment / decision is best done before landing – make the approach or change the plan. Thus, are auto-brake systems encouraging pilots to land in more marginal conditions than is sensible? Do pilots think (subconsciously) that they can ‘blame’ the autos if the landing goes wrong, thus avoid the manual option, even when the conditions indicate otherwise, or start with auto brake with a decision to change to manual based after an assessment (of deceleration) after touchdown? Too many opportunities for error. On the other hand, autobrakes are very useful, especially on x-wind landings on which rudder is applied and it is difficult to manage a symetrical braking on both sides of the main wheels. The autobrake use does not prevent you from judging by yourself, either visually or through the seat of your pant (ies) whether your deceleration is adequate or not, so your comments on this respect are a bit strange to me. Taking over manually is always a possibility that we keep in mind all the time : "Back to basics" is not for the hogs only, is it ?. I have noticed, though that very few pilots are aware of their foot-braking performance availability and have seldom felt the anti-skid operating in normal conditions. May be we should re-program some sim braking situations ( I remember very well the simulated landings on an aircraft carrier...real challenge on a 737 and the penalty for failure was a crash overboard and loss of face. Did improve your manual braking, though ! RWA, 15:43:47.6 [PIC] en ambar The call comes from a reading of the baro altimeter. Procedurally, and that crew was rather into SOPs if anything, had the *amber* referred to a failure, he would have called the ECAM message. As they were in the approach phase ( Phase 7), the warning inhibition is present and only a serious fault would be announced, with an aural warning. Doesn't seem to be the case, here. 15:45:13.4 [SIC] Spoiler Comment – that appears to have been a departure from the most prudent procedure, which I believe is to wait for the ‘spoilers’ call before deploying reverse thrust. 15:45:27.2 [SIC] SEVENTY Knots. 15:45:31.5 [CAM] (sounds of single chime) Comment – that was almost certainly a warning of some kind – but we have no way of knowing what it was. The definition of a *Level 2* amber caution is : "System failure without any direct consequence on the flight safety...Crew should be aware of the configuration or failure, but does not need to take any immediate action. However, time and situation permitting, these cautions should be considered without delay to prevent any further degradation of the affected system..." Now, for the so-called "Cardiff situation" : 1. the flight crew received a warning, which may have caused a ‘Cardiff-type’ incident (in which cycling the ‘Anti-Skid’ switch eliminated the warning, but ALSO cancelled the autobrake setting) This crew made another kind of mistake - that could happen to anyone of us - in the end by not realising that they were running short of available runway. the authorities have access to the full CVR transcript, the FDR data, and the testimony of the First Officer. They must already KNOW, to quite fine limits, what probably happened. Patience...Patience ! |
Originally Posted by Lemurian
15:43:47.6 [PIC] en ambar Already covered. The F/O was referring to their being below the MDA -minimum descent altitude - indicating thus that they had to be visual (which was marginally the case).
The call comes from a reading of the baro altimeter. Procedurally, and that crew was rather into SOPs if anything, had the *amber* referred to a failure, he would have called the ECAM message.
Originally Posted by Lemurian
NO ! Max reverse is selected at touch-down. The spoiler extension comes first on the display as it has no delay and therefore announced first. The "Reverse green" call takes more time . See Bernd's link.
Originally Posted by bsieker
Most of these "what-ifs" are talked through during the landing briefing. Basically, if there really is complete mechanical/electric/electronical spoiler failure (I'm not aware of any such case), unless you're on a long, dry runway, you have no options, since procedures categorically exclude the go-around option after reverser selection. This is also the reason for some modified SOPs, where reverser selection depends on the positive "Spoilers!" call, as can be witnessed in this Video of an A320 landing at Madeira Funchal.
Originally Posted by Lemurian
It's a *Level 2* message, appearing at the end of a *Flight Phase 8* inhibition, i.e. when the ground speed is below 80 kt.
The definition of a *Level 2* amber caution is : "System failure without any direct consequence on the flight safety...Crew should be aware of the configuration or failure, but does not need to take any immediate action.
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..."
|
Reverser, Spoilers-Call, MAX Autobrake.
Regarding Spoilers call vs. Reverse-thrust Selection:
Maybe I was a bit vague. All the SOPs I have seen say to select Reverse Thrust on main landing gear touchdown, and not to wait for spoilers. The video to which I linked does it the other way, and I do not know their operation, but it may be a special procedure for the challenging landing at Funchal, which, I believe, has a very high go-around percentage. Regarding Autobrake MAX: this setting provides maximum possible braking, limited only by anti-skid. If you have to do a landing with such a short landing distance available that it would require autobrake MAX, you would not land there. It would almost certainly severely overheat and damage the brakes and tyres. If there is absolutely no choice about it, autobrake MAX can be selected even for a landing, but it would only be done in an emergency that dictates immediate landing on the nearest hard surface, with no time for a diversion. On slippery runways, the difference between MED and MAX will be minimal, since anti-skid will normally limit braking forces to a value below the deceleration target of even autobrake MED. It will only make a difference on dry/damp stretches between contaminated areas, where a higher deceleration can be achieved temporarily. But again, a landing requiring that would be outside the normal operating limitations, and not normally be attempted, except in an emergency. This landing was not an emergency landing. Another note: Autobrake is always armed, as a fallback, even if manual braking is planned. A technicality: "70 Knots" is the standard call for reducing thrust from Maximum Reverse to Idle Reverse, reversers are normally stowed at the "Taxi Speed" call, which is probably something like 20 or 30 knots, at which point forward idle is selected instead of reverse idle. Bernd |
Bernd,
I fully agree with your post, but just a note regarding this remark: Autobrake is always armed, as a fallback, even if manual braking is planned. |
RWA,
Where is the contradiction ? In a sick mind probably. Yes, I made an error on who called the "in amber...". Big deal. I was also the one to notice who was saying what and when. But, more important, we don't KNOW whether he called the message or not - that is the point where there is a one-and-a-half-minute gap in the transcript........ 1/- During this phase, there is a landing inhibition on warnings. An amber caution light / chime will not happen, therefore, there is nothing to read / announce / call-out. The only *thingy* that would be *in amber* would be the altitude tape. 2/-The call is not"(whatever...) in amber". It is READING of the ECAM. 3/- Yeah ! You forgot the little amber creature sitting on the window sill. That would certainly explain the call. I DID see Bernd's link. Perhaps you didn't? * At touchdown : − REV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . MAX ^ . . NO CHANGE . . − GROUND SPOILERS . . . . . . . . . . . . . . . . . . . . . . . . . . . CHECK/ANNOUNCE Check that the ECAM WHEEL page displays the ground spoilers extended after touchdown. . If no ground spoilers are extended : − Verify and confirm that both thrust levers are set to IDLE or REV detent − Set both thrust levers to REV MAX, and fully press the brake pedals. Note : If ground spoilers are not armed, ground spoilers extend at reverser thrust selection on both engines. − REVERSERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CHECK/ANNOUNCE Check that the ECAM E/WD page displays that the reverse deployment is as expected (REV green). Red the first line now ? (Edit : Bernd covered well the Funchal landing vid ) |
Return to Cardiff
I notice that a few things need to be cleared on the subject of that incident and I am running the risk of not making myself clear enough.
I questioned a few times the crew actions and this is why : First, let's see the text that my friend RWA quoted : "The approach was uneventful until, passing 1,000 feet, the aircraft's status page changed from Cat III DUAL to CAT III Single. This downgrade meant that any single system failure would terminate the automatic approach. Simultaneously, an amber STEERING caption was noted on the ECAM's WHEEL page. A cycling of the A/SKID & N/W STRNG extinguished the caption and a restored status of Cat III DUAL then showed. Neither pilot could recall re-selecting autobrake after cycling the switch. After touchdown and idle reverse selection, the copilot noted that the autobrake was not functioning and called out "Manual Braking." The pilot selected full toe-braking, but gingerly and over a period of 10 seconds. Eventually recognizing "no joy on the braking front," he applied full reversing and instructed the copilot to cycle the A/SKID & N/W STRNG switch. This had nil effect, so he ordered the switch turned OFF in order to access stored hydraulic pressure in the accumulator. Braking was now available, and he urgently brought the aircraft to a halt. With three tires burst and a fourth damaged, the runway was blocked until the tires were changed." Final approach, below stabilisation altitude, gear and flaps down. Right ? Then : "...an amber STEERING caption was noted on the ECAM's WHEEL page..." "...A cycling of the A/SKID & N/W STRNG extinguished the caption and a restored status of Cat III DUAL then showed...." On ground for ...WHEEL N/W STRG fault in order to go back to the gate for troubleshooting.Taxi with care, at a taxi speed of ten knots. The BSCU reset should be performed on ground with aircraft stopped and parking brake applied by switching the A/SKID & N/W STRg selector off then on.... In flight for BRAKES SYS 1 (2) FAULT or BRAKES BSCU CH 1 (2) FAULT. The BSCU reset should be performed with landing gear retracted by switching the A/SKID & N/W STRG selector off then on...." Did I say flippant operation ? Verging on the "dangerous practice", too, I think. Now the landing part and the emergency procedure : recognizing "no joy on the braking front," he applied full reversing and instructed the copilot to cycle the A/SKID & N/W STRNG switch. 1/-A release of the foot brakes 2/-Putting the said selector to off AND LEAVING IT THERE. 3/-Use the foot brake on the alternate source. Did I say limited knowledge of the emergency procedures ? |
[quote=Lemurian]Oh ! For crissake, listen to all the explanations given to you over these past years about procedures and call-outs ![quote]
Well, for your part, please re-read what I said?
Originally Posted by RWA
Possibilities –
1. the flight crew received a warning, which may have caused a ‘Cardiff-type’ incident (in which cycling the ‘Anti-Skid’ switch eliminated the warning, but ALSO cancelled the autobrake setting) OR 2. Any warning was about something else, OR 3. The pilot was only referring to the RA readout. In connection with 'evidence,' it's possible to prove that the transcript has been 'doctored.' Doesn't the A320 GPWS call out hundred-foot points before touchdown - 'three hundred, two hundred, one hundred' etc.? No record of those in the transcript. So, between 1,000 feet and the forty-foot call, anything could have been happening and anything could have been said - and we wouldn't know. Regarding 'wait for spoilers,' all I said was:-
Originally Posted by RWA
Comment – that appears to have been a departure from the most prudent procedure, which I believe is to wait for the ‘spoilers’ call before deploying reverse thrust. The reason being that, especially on a short runway, deploying the reversers largely rules out the option of a go-around, because of the time needed to re-stow them. Doesn’t appear to be relevant, though, as the F/O confirmed the spoilers.
Now that it's been mentioned, though, can anyone please tell me how the PNF checks that spoilers have deployed fully on an A320? Can it be done visually - craning your neck through the side window - or is it just a matter of checking a light on the panel? |
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