A320 Green+Yellow fail
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Rocket3837
I do not see any other logic in it. However it does change the VFE incorrectly and the QRH adds to the cofusion by saying at the bottom of the Landing with slat or flap jammed CL
"in some cases MAX SPEED-10 may be a few knots higher than the VFE. In this situation, pilots may follow the VFE". I cannot see why will this happen.
I do not see any other logic in it. However it does change the VFE incorrectly and the QRH adds to the cofusion by saying at the bottom of the Landing with slat or flap jammed CL
"in some cases MAX SPEED-10 may be a few knots higher than the VFE. In this situation, pilots may follow the VFE". I cannot see why will this happen.
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BTW it happened, again....
Incident: Air Canada A319 near Winnipeg on May 30th 2012, two hydraulic systems failed after leak
Incident: Air Canada A319 near Winnipeg on May 30th 2012, two hydraulic systems failed after leak
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Could it be because, in case the system is recoverable in case of Low Pressure or Overheat and the condition disappears later and we recover the system we can get the surfaces moving?
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I received a reply from airbus that they have stated at the time of certification that all abnormal landings will be in flap3. So to confirm to that in G+Y fail the lever is moved to 3 even though the nothing moves.
Very nice topic!
As a few people have stated correctly the Egpws system uses actual flap (not slat) position to determine whether it is configured for landing. So in the case of Blue HYD Remaining the procedure calls for EGPWS flap mode off to not get a nuisance warning on landing.
Making an approach with flap lever in position 2 or 3 will not make any difference to the slats actual position for landing BUT it does make a huge impact for the Go around...the approach is already being flown very close to VLS but now we must consider in the event of a Go Around the Gear now remains down (gravity extension), no use of the Stab trim available as this is powered by Green and Yellow HYD systems (so now a positive force must remain on the side stick to follow the correct pitch attitude safely as we are in DIRECT law) and also remember we have zero protections now also. VLS and VSW are very close on this kind of approach. Basic aerodynamics to conclude this really nice topic...Making an approach in config 2 then innitainating a go around and moving the flap lever up one stage in this condition would not be a wise idea as this has a good possibility of a stall.
Hope that is fairly clear and am happy to concede defeat on any of what I have stated above.
As a few people have stated correctly the Egpws system uses actual flap (not slat) position to determine whether it is configured for landing. So in the case of Blue HYD Remaining the procedure calls for EGPWS flap mode off to not get a nuisance warning on landing.
Making an approach with flap lever in position 2 or 3 will not make any difference to the slats actual position for landing BUT it does make a huge impact for the Go around...the approach is already being flown very close to VLS but now we must consider in the event of a Go Around the Gear now remains down (gravity extension), no use of the Stab trim available as this is powered by Green and Yellow HYD systems (so now a positive force must remain on the side stick to follow the correct pitch attitude safely as we are in DIRECT law) and also remember we have zero protections now also. VLS and VSW are very close on this kind of approach. Basic aerodynamics to conclude this really nice topic...Making an approach in config 2 then innitainating a go around and moving the flap lever up one stage in this condition would not be a wise idea as this has a good possibility of a stall.
Hope that is fairly clear and am happy to concede defeat on any of what I have stated above.
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Making an approach in config 2 then innitainating a go around and moving the flap lever up one stage in this condition would not be a wise idea as this has a good possibility of a stall
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he never said the stall speed was lower dependant on the lever.
and maybe you don't put the flaps up when doing this landing BUT it can still be a precaution by airbus for the case a pilot puts the flaps up 1 notch.
and maybe you don't put the flaps up when doing this landing BUT it can still be a precaution by airbus for the case a pilot puts the flaps up 1 notch.
Hi Vilas
You are right (Kind of...) No where does it specifically specify you are to remain in the selected lever position during a Go around, although it does state if a circuit is planned then to leave it there. I'm pretty sure if Airbus had concerns they would make this in bold capitals but it tell us to clean up if a diversion is planned and I'm pretty confident having the lever in Flap 3 will keep us safe if we retract a stage of flap. In addition to a slat only approach our pitch attitude is already high compared to a normal Slat/Flap approach and pilots may have a tendency to raise the nose by the same amount as they normally would then if we factor in a stage of slat being removed if we were to make an approach in flap lever 2 then retracting a stage during a Go around...well you get my point.
But as mentioned above i did not state that Vls is dependent on lever but actual aircraft config. So in our case 2 stages of Slat only. If we were to retract a stage through force of habit from flap position 2 to 1 then we would change the actual config and would be in a possible sticky situation. If you get time Google 'Confirmation bias' it's very interesting what we as humans do in situations even when told what to expect.
Airbus is by no means perfect, and they know this! This procedure is a result of sensible thinking by the people who have designed this aircraft and seen the pitt falls through thousands of hours of simulated malfunctions and issues that have probably helped mould this procedure the way it is written today.
A good example of this is in the Green and Blue Dual Hyd failure were the procedure asks us to select manual thrust at around 200Kts...This is because the aircraft is in an aerodynamic mess (partial use of only half the elevator no aileron and 2 roll spoilers per wing to be used for banking) The designers were wise enough see that with the extension of the gear putting the aircraft into direct Law and flying at the approach speed (which again would be close to Vls and VSW) the aircraft MAY not cope well, hence the extension at 200kts and with manual thrust (they do not trust their own equipment in this particular circumstance) Could we leave the Auto thrust in...Yes. Would we crash...probably not. Is it wise...I would say no.
Could we fly and approach (G and Y Dual Failure) in flap lever 2...Yes but once again probably not wise.
You are right (Kind of...) No where does it specifically specify you are to remain in the selected lever position during a Go around, although it does state if a circuit is planned then to leave it there. I'm pretty sure if Airbus had concerns they would make this in bold capitals but it tell us to clean up if a diversion is planned and I'm pretty confident having the lever in Flap 3 will keep us safe if we retract a stage of flap. In addition to a slat only approach our pitch attitude is already high compared to a normal Slat/Flap approach and pilots may have a tendency to raise the nose by the same amount as they normally would then if we factor in a stage of slat being removed if we were to make an approach in flap lever 2 then retracting a stage during a Go around...well you get my point.
But as mentioned above i did not state that Vls is dependent on lever but actual aircraft config. So in our case 2 stages of Slat only. If we were to retract a stage through force of habit from flap position 2 to 1 then we would change the actual config and would be in a possible sticky situation. If you get time Google 'Confirmation bias' it's very interesting what we as humans do in situations even when told what to expect.
Airbus is by no means perfect, and they know this! This procedure is a result of sensible thinking by the people who have designed this aircraft and seen the pitt falls through thousands of hours of simulated malfunctions and issues that have probably helped mould this procedure the way it is written today.
A good example of this is in the Green and Blue Dual Hyd failure were the procedure asks us to select manual thrust at around 200Kts...This is because the aircraft is in an aerodynamic mess (partial use of only half the elevator no aileron and 2 roll spoilers per wing to be used for banking) The designers were wise enough see that with the extension of the gear putting the aircraft into direct Law and flying at the approach speed (which again would be close to Vls and VSW) the aircraft MAY not cope well, hence the extension at 200kts and with manual thrust (they do not trust their own equipment in this particular circumstance) Could we leave the Auto thrust in...Yes. Would we crash...probably not. Is it wise...I would say no.
Could we fly and approach (G and Y Dual Failure) in flap lever 2...Yes but once again probably not wise.
Last edited by EGKK.; 15th Dec 2017 at 20:54.
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EGKK
You didn't write clearly what you explained now. However I am the one who started this thread five years back to get an answer and all these thoughts went through my mind. So later I asked the airbus about it also stating that unnecessarily moving the flap lever to 3 causes the VFE to be displayed incorrectly. They did not give the reason of safer GA in three. I will reproduce a small part of it below.
Perhaps Airbus themselves had noticed it because in A330 they had changed it. If you see the same failure in A330 QRH it tells you to land in flap2.
Also flap retraction of one step in all cases is not required and this was discussed sometime back. You can search for it. Retraction of one step in GA is due to high drag in flaps full. Conf1, 2, and three are take off configs and do not mandatorily require retraction especially in 1 and 2. There is also airbus discussion on this.
You didn't write clearly what you explained now. However I am the one who started this thread five years back to get an answer and all these thoughts went through my mind. So later I asked the airbus about it also stating that unnecessarily moving the flap lever to 3 causes the VFE to be displayed incorrectly. They did not give the reason of safer GA in three. I will reproduce a small part of it below.
I agree with you that selection CONF 2 during approach, and maintaining CONF 2 for Go-Around could have been less misleading for the pilot. But the rationale of selecting CONF 3 for A320 family aircraft is historical, as this configuration has been proved, in terms of certification, as being the optimum one in terms of handling qualities in alternate law.
Also flap retraction of one step in all cases is not required and this was discussed sometime back. You can search for it. Retraction of one step in GA is due to high drag in flaps full. Conf1, 2, and three are take off configs and do not mandatorily require retraction especially in 1 and 2. There is also airbus discussion on this.
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EGKK
Really? It gets very interesting when it comes to retracting flaps(slats actually). The QRH says for diversion if flaps jammed at zero select clean configuration. Maintain speed close to Vapp(Due to pitch trim unusable). The problem is F and S speeds are false and they will take you for a ride. How and when do you retract the slats? Airbus doesn't tell you what to do
Never do anything out of bias.
For 60T the Vref is 130+25 the Vapp is 155kts. You cannot retract at that speed. You need to increase the speed close to 195 before retracting and once in clean you cannot come back to 155kts. You have to fly out of trim to save your life. What QRH says is poppy cock. All this needs to be thought of and briefed before the approach begins. So diversion is virtually out of question. Do your FORDEC carefully. May be another few approaches but diversion? No way!
No where does it specifically specify you are to remain in the selected lever position during a Go around,
If you get time Google 'Confirmation bias' it's very interesting what we as humans do in situations even when told what to expect.
For 60T the Vref is 130+25 the Vapp is 155kts. You cannot retract at that speed. You need to increase the speed close to 195 before retracting and once in clean you cannot come back to 155kts. You have to fly out of trim to save your life. What QRH says is poppy cock. All this needs to be thought of and briefed before the approach begins. So diversion is virtually out of question. Do your FORDEC carefully. May be another few approaches but diversion? No way!
Last edited by vilas; 16th Dec 2017 at 15:16.
