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lewismorrison22

Step Climb Not Working.

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Ok, I've tried to figure this out but I can't so I'm hoping someone on here will be able to help...

 

So, when I'm programming the FMC for a long flight and there are planned step climbs, I go to the way point in which I must climb and put in the new altitude followed by an 'S' for example, I may put '/370S' and this works as it should, i.e. it will change all the following way point to 37000FT.

 

The problem I face is with the auto step climb feature.  It simply does not work when I turn the feature on.  

 

So here is a quick example.  Im flying LAX - DXB.  My initial altitude is 370, with a step to 390 - I programme the FMC appropriately and will have 370 set in the MCP.  However, when I reach the SC point, nothing happens.  The MCP does not change and the aircraft does not climb. I've also tried putting 390 in the FMC before the SC point, but the aircraft still does not climb automatically.  I am at a loss.

 

Any help is greatly appreciated.  

 

Lewis

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Any help is greatly appreciated.  

 

Lewis,

 

There are a couple things here.

 

Firstly, while I commend you for looking ahead at the planned step climbs in your flight plan, these are flatly ignored by the flight crew in favor of the calculated OPT altitude step climb tracked by the FMC (there are some circumstances, though, in which they are used). Even though these points appear in your flight plan, they are merely there to give the ATC computers an idea of what your flight plans on doing. Actuality will likely be different, and this is why we have controllers controlling the traffic and not a big computer coordinating traffic and giving commands. All this is to say that, unless you have a verifiable reason (an altitude restriction along the route, busy NATs where you don't think you'll get a climb, and so on), don't force the step climbs per your route plan. Just know that the plan is that you'll climb somewhere near those points.

 

Secondly, the requirements (that I'm aware of) for AUTO STEP CLIMB to work are:

  • The feature must be enabled in the PMDG SETUP menu; and
  • The CRUISE ALT and MCP ALT match your current altitude prior to the step point (the CRZ ALT on the cruise page matches the altitude you're currently flying, along with the MCP ALT).

I don't think forced step points should interfere with the function of this feature, but I'll check. If you can provide screenshots of what you're seeing where you're meeting the requirements and it's still not working, it'll help me verify where the issue is here.

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, these are flatly ignored by the flight crew in favor of the calculated OPT altitude step climb tracked by the FMC (there are some circumstances, though, in which they are used). Even though these points appear in your flight plan, they are merely there to give the ATC computers an idea of what your flight plans on doing. Actuality will likely be different, and this is why we have controllers controlling the traffic and not a big computer coordinating traffic and giving commands.

 

That is true -- so much so, in fact, that I seem to remember reading somewhere that Eurocontrol were getting cheesed off with the number of flights filing one altitude at various points along the route and flying another because it was screwing their flow management (as an example, if there's a sector split at FL300 and you have 10 aircraft filed at FL330 and another 10 filed at FL280, there's no problem -- but if the 10 aircraft that filed FL280 at that point turn up flying at FL350, suddenly the upper sector has an extra 10 aircraft they weren't expecting to have to handle).

Edit: Found the link! https://www.eurocontrol.int/press-releases/promoting-flight-level-adherence-across-europe

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The feature must be enabled in the PMDG SETUP menu; and

It also needs yes, allow, or something along those lines in the auto cruise section of FS Actions.

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It also needs yes, allow, or something along those lines in the auto cruise section of FS Actions.

 

If you're using Auto Cruise, yes. If you're not using time compression, though, all you should need is the AUTO STEP enabled.

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Lewis,

 

After you have ensured the two conditions below are satisfied:

 

 

 


The feature must be enabled in the PMDG SETUP menu; and
The CRUISE ALT and MCP ALT match your current altitude prior to the step point (the CRZ ALT on the cruise page matches the altitude you're currently flying, along with the MCP ALT).

 

And you still are unable to AUTO Step Climb, then you have entered a /FL***S that is above your current MAX altitude in the VNAV CRZ page. 

 

 


So here is a quick example.  Im flying LAX - DXB.  My initial altitude is 370, with a step to 390 - I programme the FMC appropriately and will have 370 set in the MCP.  However, when I reach the SC point, nothing happens.  The MCP does not change and the aircraft does not climb. I've also tried putting 390 in the FMC before the SC point, but the aircraft still does not climb automatically.  I am at a loss.
 

 

Lewis,

 

The following conditions will prevent AUTO step climb from working:

 

1. STEP SIZE: 0 is entered by the pilot.

2. Example, you enter /FL370S for waypoint XYZ. If at waypoint XYZ, the aircraft weight is above the current MAX (found on the VNAV CRZ page), then the AUTO step climb will occur at a later point, anywhere after XYZ and not a fixed later waypoint.

 

What is a easy way to tell if you have entered a /FL***S that is above the MAX alt for a specific waypoint?

 

Example 1: FL330S entered at XYZ, MAX alt is FL353 overhead XYZ

 

XYZ .831/FL330S

ABC .832/FL330 (71NM from XYZ)

DEF .831/FL330 (101NM from ABC)

 

In the first example you can see the planned /FL330S will occur as planned once passing overhead waypoint XYZ.

 

Example 2: FL360S entered at XYZ, MAX alt is FL353 overhead XYZ

 

XYZ .831/FL360S

ABC .832/FL353 (71NM from XYZ)

DEF .831/FL355 (101NM from ABC)

AWD .833/FL360 (56NM from DEF)

 

In the second example, when passing overhead waypoint XYZ the MAX alt (based on aircraft weight) is FL353. Hence the S/C symbol on the ND, is located at a point after waypoint XYZ where the MAX alt is FL360 or higher. In this example that point was after waypoint DEF, hence the AUTO step climb to FL360 will occur at that later point and not the originally entered waypoint XYZ.

 

You can tell this is going to happen because although you entered /FL360S at XYZ, the following two waypoints in sequence are showing a ALT below the intended /FL360S, until waypoint AWD by which time the AUTO step to FL360 will have occurred.

 

As a rule of thumb on the -300ER, MAX alt increases by 100ft every 10 minutes.

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If you're using Auto Cruise, yes. If you're not using time compression, though, all you should need is the AUTO STEP enabled.

Learn something new everyday. If both Auto Step Climbs are No - in PMDG Setup and FS Actions If Yes is selected in PMDG Setup, FS Actions is automatically changed from a No to a Yes. I thought FS Actions had to be a Yes before Auto Step Climb in PMDG Setup could be answered Yes. That is not the case.

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