FMA A320 modes

[AF330 0]

Ok so if we are not in managed mode (selective mode: OP CLB...) it will show first arm ALT in blue on the second line and OP CLB on the first line. When we we will reach the altitude on the FCU, it will show ALT* in green on the first line.

 

But when we are in managed mode, ALT will arm only if we have to pass over/under a waypoint in blue on the second line. If the next waypoint is an ALT CST, it will arm ALT CST in magenta (second line). On the first line, we can read CLB or DES. When we have to level-off on one of our waypoints, it will show ALT CST* on the first line in green.

 

1) Everything right?

2) So ALT basically means that we are flying without any level-off, right?

3) So we can never read ALT on the first line?

 

4) So blue = armed

- Green = when we are at level. Right?

 

5) In managed mode, if we don't have to level off, it will show ALT in blue on the second line? If yes, it would mean that we can read that we can only read ALT CST* on the first line.....

 

Thanks

[Don t moderate me this way 882]

A couple of "colour assignments" for the FMA, roughly speaking - you have all the detailed resources at your fingertips already:

 

blue = armed (selected)

magenta = armed (managed)

green = active

white = automation status (A/THR, A/P, F/D)

 

As an example: Imagine you are in a managed descent with altitude constraints:

 

If you dial in an altitude (in your ALT window on the FCU) higher than the constraint: ALT arms in blue (a pilot-selected ALT limits your descent)

If FCU ALT is lower than your constraint: ALT arms in magenta (a STAR-related ALT limits your descent, so kind of "managed")

 

CSTR never gets armed; it's ALT that will be armed. CSTR is for active modes only. The CSTR information is covered by the colour magenta of the armed ALT.

 

ALT is shown in green when ALT capture (ALT* = ALT star) has completed. If the altitude kept is your cruise altitude, the FMA shows ALT CRZ in green.

[AF330 0]

Wood: "If 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."

 

Thanks olli!

 

1) But he/she says that if you are in managed mode and if your next waypoint is an ALT CST, it will show ALT CST in magenta on the second line. (So it has captured it, basically armed it!) Do you agree?

 

2) You say: " If you dial in an altitude (in your ALT window on the FCU) higher than the constraint.... [...]"

 

How can you have constraints if you enter an ALT on the FCU? It would mean that you are in managed mode. But which constraint are you talking about? If you enter an ALT in managed mode, it will respect every constraint till that altitude (entered on the FCU) and level off there (entered in the FCU). Wood said that if your next waypoint is a CST, in managed mode, it will show ALT CST in magenta and ALT if it is not a CST (so you don't have to level-off). So which constraint are you talking about?

 

3) You said that blue = armed and selective mode

 

But you can read ALT in blue if you are in managed mode, AND if your next waypoint is not a CST (you don't have to level-off)

 

Thanks

[Don t moderate me this way 882]

1)

Different software version?

 

2)

Constraints related to the following waypoints. My example was a STAR (STandard Arrival Route) which very often contain CSTRs.

 

3)

I think I mentioned that in my example. Mind that a managed descent is carried out no further than to the higher one of two altitudes: a) altitude in the FCU ALT window (this is a pilot-selected figure), b ) altitude in an ALT CSTR (this is coded into the navdata, so part of the managed side of things)

Bottom line is:

A managed descent right down to the FCU ALT is a descent down to a selected (= pilot-selected) altitude ... so shows in blue, despite the fact that the descent is still managed.

[AF330 0]

http://www.youtube.com/watch?v=bjGT9aJU6jo

 

It's a very nice video! 

 

So when it is an OP CLB, here are the steps:

 

1) It shows on the first line OP CLB in green.

2) It arms ALT (in blue) on the second line.

3) It captures the selected altitude and shows ALT* in green (which means that it has been captured) on the first line.

4) ALT is green, the altitude has been held.

 

 

So when it is a managed climb and if our next waypoint is an ALT CST, here are the steps:

 

1) It shows on the first line CLB in green.

2) It arms ALT CST in magenta on the second line.

3) It captures the selected altitude and shows ALT CST (which means that it has been captured) in green on the first line.

4) ALT CST is green, the altitude constraint has been held.

 

I am not sure of this one, Wood and Olli are saying 2 different things!  ^_^ 

 

 

So when it is a managed climb and if our next waypoint is not an ALT CST, here are the steps:

 

1) It shows on the first line CLB in green.

2) It arms ALT in blue on the second line.

3) It passes over/under the waypoint at X altitude and shows ALT* (which means that it has respected the CST) in blue on the second line.

4) We can still read CLB in green on the first line.

 

So when we enter a V/S, here are the steps:

 

 

1) It shows on the first line V/S in green.

2) It arms ALT (in blue) on the second line.

3) It captures the selected altitude and shows ALT*  in green (which means that it has been captured) on the first line.

4) ALT is green, the altitude has been held.

 

Everything right?  :rolleyes:

 

Take care,

AF330