FMA A320 modes

[AF330 0]

Hi!

 

I wanted to learn the different modes we can read on the FMA for HDG and ALT with the colours.....etc. I read F-COM Autoflight and wanted to confirm what I had understood and ask some questions!

 

ALT.

 

On the FMA, when you can read ALT, are you flying the plane manually? Because you have 4 modes for altitude:

 

- CLB (managed)

- OP CLB (Selective)

- V/S (vertical speed)

-ALT!

 

Thanks!

[woodreau 0]

The only part of the FMA that indicates you are hand flying is in the upper right. If there is no AP1 or AP2 or AP1+2 annunciated you are handflying.

 

All the other annunciations in the FMA indicate what flight guidance modes are provided with the flight director.

 

If you handfly with the flight directors off, nothing will be annunciated in the FMA.

[AF330 0]

Thanks a lot!  :smile:

 

But what is ALT mode??? 

[michal 44]

I don't know Airbuses but in many other AP/FD systems ALT simply means you are in altitude hold mode. I have ALT in my Cirrus/G1000 that I fly and this is what it means.

[AF330 0]

Ah....so when you are at level?

 

Thanks

[WfordJr 1]

Altitude capture

[AF330 0]

Euh....wait! Getting confused....

 

1) Altitude capture = Altitude captureD?

So when you are in an OP CLB, CLM, V/S...etc, it will arm ALT? And when you reach your next altitude (on the FMGC or the FCU), it will show ALT?

 

2) If it is altitude captured, in managed mode, is it only for waypoints where we have to level-off?

 

Thanks

[AF330 0]

Hey.... read F-COM 1.22.30 P71 SEQ 110 REV 35 - Autoflight A320.

 

For altitude on FMA, it says:

 

ALT* : ALT* green, in case of FCU selected altitude capture.

ALT CST* : ALT CST* green, in case of ALT CSTR capture (vertical profile)

ALT is green, when the FCU selected altitude is held.

ALT CST: ALT CST is green, when an ALT CST is held (vertical profile)

 

1) Ok..... So when we are in managed mode, and our ALT CST is approaching, it will show ALT CST* in green, right?

 

2) When we enter an altitude in the FCU, and if we haven't captured it yet, it will show on the FMA ALT* in green, right?

 

3) When our managed altitude is held, it will show ALT CST in green, right?

 

4) When our FCU altitude is held, it will show ALT, right?

 

5) Sometimes, we just have to pass a waypoint over X altitude. Is that considered as ALT CST? Because we don't have to level-off....if yes, when we will pass over that waypoint over X altitude, will it still show ALT CST (it can only happen in managed mode)?

 

Thanks a lot!

[AF330 0]

Well....what is the difference between held and captured?  :unsure:

[Don t moderate me this way 882]

"Held" is "exactly at" an altitude/FL and keeping it.

 

"Captured" is "still acquiring" an altitude/FL - you are close, but haven't reached it yet exactly. Still slowly climbing or descending.

[AF330 0]

Thanks a lot....

 

So what is "armed"? If ALT (CST) * means that you are going to held the altitude (capture). But when ALT (CST) is in displayed in blue, it's armed! So what is the difference between arm and capture?

 

Thanks

[woodreau 0]

Whenever you set an altitude in the FCU, you are telling the FMGC that you want a different altitude than the one the aircraft is currently at.

You then pull or push, depending on what you want to do.

 

If you pull, you will either get an OP CLB or OP DES.  In an OP CLB or OP DES, the aircraft will ignore any altitude contraints set in the FMS.  So it will only show ALT in cyan underneath OP CLB or OP DES.

 

If you push, the aircraft will attempt to honor any and all altitude constraints set in the FMS.  You will get CLB or DES then underneath CLB or DES, it will either show ALT in cyan or ALT CST in magenta.   There may be an altitude constraint set in the FMS.  If the FMGC calculates the aircraft will meet the altitude constraint without having to stop at the altitude constraint, it will just show ALT in cyan.   If the FMGC determines the aircraft needs to level off at the altitude constraint, it will show ALT CST in magenta and then indicate what altitude it is constrained to on the altitude tape of the PFD in magenta.

 

Once the aircraft gets to the point of altitude capture, the ALT/ALT CST transitions from the second line to the top line of the FMA to show either ALT* or ALT CST* to indicate it is in the process of capturing the altitude that is either set in the FCU or the altitude constrained by the FMS.     Once the altitude is captured the FMA will display one of the following ALT, ALT CRZ, or ALT CST, depending on the situtation.

 

If it is ALT CST, the aircraft will only level as long as it is constrained, after it passes the constrained waypoint, it will resume the climb or descent to the altitude set in the FCU.  At which point it will then show either CLB or DES, with ALT in cyan underneath, and the FCU preselected altitude in cyan on the altitude tape of the PFD.

[michal 44]

 

 

So what is the difference between arm and capture?

James Bond was ready and armed ...

 

.. so he could attempt to capture Blofeld.

 

Do you now see the difference between 'arm' and 'capture'?  :wub:

[Don t moderate me this way 882]

"Armed" is a "preview" of "the mode after" the current one. May be oversimplified, but I hope it still helps.

[AF330 0]

Thanks a lot....

 

Is their a code for colours?

 

Blue = ?

Green = ?

Magenta = ?

White =?

 

Thanks....