Managed Climb with Selected Speed

[ksp 0]

Hi,

 

I am after some help. Been flying the the various versions of your 'bus for years (great product!) and decided to finally move on from using the mouse and create my own hardwired MCP and program it using Lua and Lvars. That's another story that I would be happy share if anyone is interested. But whilst trying to program the push-pull functionality of the Altitude button I have come across something that I am not sure  is correct. And before some asks, it is the same whether I use my Lua scripts or just use the mouse on the virtual cockpit - so I know it isn't my programming!

 

In all the following cases, I am in managed heading mode, so the plane is following the lateral path of the FMGC.

 

1. In level flight, if I dial in a higher altitude, and have speed managed, pushing the altitude knob, commands "Thr Clb / Clb". The engines spool up to climb thrust and the bus climbs at a vs to maintain the managed speed (as expected).

2. If I do the same but pull the altitude knob, it commands "Thr Clb / Op Clb", in effect the same happens (the only difference would be if there was an altitude constraint in the flight plan, it would ignore it). Again, as expected.

3. If in level flight, I use 'selected speed' and pull the altitude knob, the same happens "Thr Clb / Op Clb"- this time at the selected speed. As expected.

4. If, however, I use selected speed and push the altitude knob, it maintains 'Speed / Clb', spools the engines up a few percent and climbs at a few hundred feet per minute. I would have expected it to engage "Thr Clb / Clb" albeit at the selected speed. Note, if you pull the knob to engage Open Climb and then push to select managed climb, it retains the "Thr Clb" setting and enters "Thr Clb/Clb" so it climbs at Climb thrust at the selected speed, observing any altitude constraints.

 

Have I misunderstood something in the logic of the FCU that doesn't select Thr Clb if the speed is managed?

 

Apologies, this is a quite a complex message - if someone wants me talk through it again or explain the permutations, I'm happy to do so.

 

Kevin

[DaveCT2003 2553]

I've asked a few of our Airbus pilots to drop by and answer.

 

Thanks for a great question!

 

[ksp 0]

Thanks guys,

 

Always reassuring to hear your not doing something wrong! Can't believe that what is probably such a well used function could have existed for so long without someone else noticing it.

 

Now that we know, Dave, how do we draw it to the attention of those who code the 'bus? I should have also mentioned I was using the A320 so 'AAC47' did you try the A330.  I don't know if it is the same code ported across and don't have the 330 to try.

 

Kevin

[masterhawk 799]

58 minutes ago, ksp said:

Thanks guys,

 

Always reassuring to hear your not doing something wrong! Can't believe that what is probably such a well used function could have existed for so long without someone else noticing it.

 

Now that we know, Dave, how do we draw it to the attention of those who code the 'bus? I should have also mentioned I was using the A320 so 'AAC47' did you try the A330.  I don't know if it is the same code ported across and don't have the 330 to try.

 

Kevin

It‘s noted.

[ksp 0]

Thanks Bob.