Slats and flaps jammed procedure A320 - Selected speed
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Slats and flaps jammed procedure A320 - Selected speed
I know this one is covered a lot. I have a very specific question relating to this procedure.
Once FULLY configured to VAPP do you stay in selected speed or can you revert to managed speed to make use of groundspeed mini.
I know that while you configure using VFE next - 5 you are in selected speed but I am referring to the time when you have configured down to the landing CONF.
I think Airbus want you to remain with selected speed so groundspeed mini doesn't interfere.
For instance, if you have slats locked between 0 and 1 and flaps locked between 0 and 1 you don't have a lot of drag. This would mean if groundspeed mini increased the IAS due to a gust then it would take the aircraft a long time to slow down (or longer than designed) and so make any landing distance calculation meaningless.
Does anyone know Airbus' official recommendation on this matter and if they have a reference then this would help me out a great deal?
Once FULLY configured to VAPP do you stay in selected speed or can you revert to managed speed to make use of groundspeed mini.
I know that while you configure using VFE next - 5 you are in selected speed but I am referring to the time when you have configured down to the landing CONF.
I think Airbus want you to remain with selected speed so groundspeed mini doesn't interfere.
For instance, if you have slats locked between 0 and 1 and flaps locked between 0 and 1 you don't have a lot of drag. This would mean if groundspeed mini increased the IAS due to a gust then it would take the aircraft a long time to slow down (or longer than designed) and so make any landing distance calculation meaningless.
Does anyone know Airbus' official recommendation on this matter and if they have a reference then this would help me out a great deal?
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The QRH states that when landing configuration is established you should decelerate to your calculated approach speed in final approach. I think the best way to do this would be to use selected speed. Notwithstanding what you said about GS Mini, the approach speed calculated from the performance tables as a result of the failure wouldn't be calculated by the FMS anyway. So the only way to fly that speed in managed mode would be to insert it into the FMGC, which just seems unnecessary to me.
But, as always, I reserve the right to be wrong.
But, as always, I reserve the right to be wrong.
I don't have time to look it up right now but I think there was a recent change on this, I believe it may have switched form suggesting managed speed to selected speed although I'm not sure if there was any explanation provided. I could speculate but you could start there of now.
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As far as the procedure goes it should be selected Vapp. If you fly managed AC will maintain Vapp as entered in MCDU but GS mini will come in. As someone raised on the other thread you could be doing this in direct law so trim changes are not desirable. At higher ∆ref even wind correction is not permitted. So in my opinion it should be flown as per procedure in select.
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I would agree. Do you happen to know what happens if both the slats and flaps are locked at zero in terms of the ecam memo?
My understanding is that this will still show a blue action line CONF FULL.
My understanding is that this will still show a blue action line CONF FULL.
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Come to think of it, how would you know if slats and flaps are jammed at zero with flap lever in zero? Move flap lever to 1 slats jammed. Do ECAM actions and prepare for flap three landing. Select flap 2 and bang flaps jammed. Now you know you have nothing and flap lever is in two. Would you take it back to one, leave it there or select three?
Don’t th ELAC commands change with flap lever position? So flap lever position 3 give optimum low speed handling. Yes, there is no flight surface difference.
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Flap three (surface position)handling is better compared to actual flaps full but in this case there is clean wing.Recommended lever setting is one but that is to get GA phase. As I said you will only discover 0/0 jam only in lever 2 position there is no point going back to 1. ELACs shouldn't play any part between 1 and 3.
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Hi vilas,
Have a look at this report:
http://ebook.lib.hku.hk/HKG/B35840213.pdf
and note the reduced roll sensitivity of the spoilers when in CONF FULL. (Appendix 13)
Have a look at this report:
http://ebook.lib.hku.hk/HKG/B35840213.pdf
and note the reduced roll sensitivity of the spoilers when in CONF FULL. (Appendix 13)
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GR
The accident on the link was discussed some months back. Before posting present comment I thought about it but was unable to access it. The performance and drag are less in conf3. The gains are modified in flaps full making it less sensitive. Conf3 is also take off Conf may be that has something to do. But does it translate into better handling in full I am not sure.
The accident on the link was discussed some months back. Before posting present comment I thought about it but was unable to access it. The performance and drag are less in conf3. The gains are modified in flaps full making it less sensitive. Conf3 is also take off Conf may be that has something to do. But does it translate into better handling in full I am not sure.
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Some years ago my choice on a gusty day (no windshear) was CONF 3, after one particular approach into BRU when i landed with full lateral deflection to the left and very little control, i changed to CONF FULL (as recommended by Airbus). I've yet to experience the lack of control. It may be the spoiler logic (try looking at the spoiler deflection in the sim in CONF 3 vs CONF FULL in a gusty approach) or just the FBW being better tuned for FULL ... no idea, but it works !
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Just two points if I may and I've been off the aircraft so my memory may be failing me!
- If you end up landing in direct law, the position of the flap lever isn't going to make much difference to the handling qualities.
- As I remember it, Vmax (barbers pole) displayed on the PFD is a function of flap lever position rather than actual flap position. With a clean aircraft would you really leave Vmax at 185kt for Flap 3....
- If you end up landing in direct law, the position of the flap lever isn't going to make much difference to the handling qualities.
- As I remember it, Vmax (barbers pole) displayed on the PFD is a function of flap lever position rather than actual flap position. With a clean aircraft would you really leave Vmax at 185kt for Flap 3....
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Further on better handling with Flap full, if you go through BEA report on Armavia A320 Sochi fatal accident there is a note which says:
FCTM
LANDING
Ident.: PR-NP-SP-10-10-2-00020711.0001001 / 22 MAR 17
Applicable to: ALL
Configuration FULL, or 3, can be used.
CONF FULL provides better handling capability in turbulent conditions, however, CONF 3 provides
more energy and less drag.
Note: In the course of experiments on the simulator undertaken in Toulouse, it was determined that when the aircraft is in landing configuration, the turn coordination function works with rather significant errors. The Airbus representatives admitted this and explained that this aircraft type was not intended for manoeuvring with high bank angles in the landing configuration.
LANDING
Ident.: PR-NP-SP-10-10-2-00020711.0001001 / 22 MAR 17
Applicable to: ALL
Configuration FULL, or 3, can be used.
CONF FULL provides better handling capability in turbulent conditions, however, CONF 3 provides
more energy and less drag.
Last edited by vilas; 27th Nov 2017 at 15:18.