Checklist with step climb

[hobeprime 16]

Hello,

is it normal that I get the descent checklist when step-climbing? There is a (closed) entry which about describes the problem:

http://forum.aerosoft.com/index.php?/topic/68017-checklist-alt-cstr-step-climb-descent/

I am at FL340, over a thousand nm away from my destination. At the FRZ VOR I have set a constraint of FL360 in order not to forget the climb. (The reason can be fuel efficiency or because the airway system changes (e.g. Southern Europe)).

After having passed my waypoint I select 37000ft in my FCU (or first in the MCDU PROG CRZ) - the aircraft begins to climb.

So far, so good. The thing is: I get the descent prep checklist and the "initiate descent" in the green info bar. I have never intended to descend but to climb instead. As soon as I have any change in the flight level, the checklist assumes I would like to begin my descent.

Is this normal, i.e. just a limitation of the right MCDU/checklist? Am I doing something wrong?

Thanks,

kind regards,
Dennis

[Guest]

Hi Dennis,

I believe the problem is in connection with the calculated TOD, the FL acording to your MCDU entry and your waypoint with a constraint of 36.000 feet.

• Your FL according to the MCDU is 34.000 feet because I can see from the screenshots that you already reached ALT CRZ.
• You are stating that you are app. 1.000 NM away from your destination but the TOD marker on the ND says something different.
• And this might be the problem because the information regarding the descent starts app. 10 NM before the calculated TOD.

So I would suggest to do it a different way. Use step climb and set the MCDU FL to 36.000 feet and the FCU ALT to 34.000 feet. Please let me know what then happens to the calculated TOD..........

Regards,

Hanse

[hobeprime 16]

Hello Hanse,

thanks for your reply.

• It is true. I have already reached ALT CRZ because that is the first requested flight level. The step to FL 360 happened about 600nm after departure and there is no point in flying in CLB mode for 600nm.
• When you take a look at my second screenshot (the MCDU) you will in the bottom line see: DEST(ination) LPPT ... DIST(ance) 1028 (nm).

What do you mean by "use step climb"? Is that a feature in the MCDU that I have missed?

As far as I can see, the problem is that the aircraft regards the first vertical constraint after having reached ALT CRZ as a descent without checking if it might be a climb instead.

I can try your suggestion at my next flight but I predict that I will fly in CLB mode all the way until I can climb the next step. Long routes have multiple step climbs so that I would fly in CLB mode for about two thirds of the route which (in that case, which was LROP-LPPT at 1613nm/4h15m) would be quite a prolonged climb?

I am not sure if I am being clear enough in what I would like to say... I'll check at my next flight.

Thanks so far!

Dennis

[hobeprime 16]

Hello again,

I reread the whole documentation but did not find anything about step climbs.

So I tried to do what you suggested and here we go: It is as I had predicted: The aircraft (MCDU) remains in CLB mode and pushes the blue arrow for the final cruise level always a few miles ahead until I finally go to final cruise level. The TOD is correctly calculated because the aircraft never gets another input.

The thing that I would like to have with a given flight plan is to set a reminder for me when to climb. The aircraft does do that (as described in the posts above), though I must admit that I do not know how this is in reality.

And the problem now is that apparently the checklists do not expect a climb from CRZ but identify every horizontal change as a descent and therefore call up the descent preparation checklist.

Now the question is: can this be changed so that it realizes it is not a descent but a climb instead?

Thanks,

Dennis

[Guest]

Hi Dennis,

I think the "reminder" you are looking for is aslo not availabvle in reality. Constraints are only used during climb and descent/approach. Everything during cruise is done manually and in connection with ATC. Maybe you can use the functionality "PAUSE AT NEXT WPT" as a reminder (because the distance between your varous waypoints is quite long) as I saw from the screenshots. Another opportunity might be to set the FL p.e. to 36.000 feet (MCDU and FCU) and for all waypoint before enter a constraint of p.e. 31.000 feet. That should work but it means some more work .......

Did you really try the following if you want to climb again - the PFD FMA already states ALT CRZ: First change = increase the MCDU FL ALT on the INIT A PAGE and then change the ALT on the FCU and push the button. The plane starts to climb. I just tried it and it works perfectly i.e. no DESCENT PREP CL.....

Regards,

Hanse

[hobeprime 16]

[...]

Did you really try the following if you want to climb again - the PFD FMA already states ALT CRZ: First change = increase the MCDU FL ALT on the INIT A PAGE and then change the ALT on the FCU and push the button. The plane starts to climb. I just tried it and it works perfectly i.e. no DESCENT PREP CL.....

Regards,

Hanse

Hanse,

yes that works but I still have to know when to climb and since I don't have a PnF I have no one to remind me...

But thank you for your efforts and explanations, much appreciated!

Dennis