Slats and flaps jammed procedure A320 - Selected speed

[applecrumble]

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?

[Dracarys]

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. :p

[Willie Nelson]

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.

[vilas]

Very recently this thread was started by Boyington. You may check.

[applecrumble]

What do you personally teach to people doing a type rating Vilas.
What are your views on it?

[vilas]

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.

[applecrumble]

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.

[vilas]

ECAM MEMO is dependant on law. In normal it should show FULL and in Alternate Flap3.

[applecrumble]

So the ECAM memo will remain blue in the case of slats and flaps jammed (flap lever 1 for landing)

[vilas]

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?

[compressor stall]

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.

[vilas]

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.

[dkz]

@Vilas: Actually flaps Full has better handling capability but flaps 3 offers less drag.


Pro-Sup-91-10-Landing

[vilas]

dkz
Strange but true. And yet all abnormal landings are in flaps3.

[Goldenrivett]

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)

[vilas]

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.

[dkz]

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 !

[Cough]

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....

[vilas]

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:
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.
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.

[MD83FO]

Hello! What’s the reason for separate performance on flaps slats locked vs flaps slats fault?

[vilas]

whats the meaning of separate performance? Can you clarify a little?

[vilas]

The FWC uses the term Fault as SFCC problem and ECAM asks you to recycle the flap lever which may get rid of it like restarting your mobile. Locked is is a term used for hydraulic wing tip brake activation where the flap/slat is stuck without a remedy.
However in performance page for landing distance etc. there's only one term used for both and that is Fault. It's because if the surface is stuck then performance wise the reason is immaterial. There are no different tables flaps slats locked Vs flaps slats fault. There are four tables given:
1. Flaps fault, it gives performance for various flap stuck positions but slats are free.
2. Slats fault, this gives various slat stuck positions but flaps are free.
3. Flaps and slats both stuck at zero.
4. Flaps and slat both stuck at different combinations of positions

[MD83FO]

Ok I see, it’s just offering all the combinations, aren’t some of those repeated? I think the flaps fault, slats fault option is kinda redundant, as the lower part of the table offers all the combinations.