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NPA and A/P disconnection


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Hi,

I'm studying NPA on A320 v1.31 (FsxSp2) following the step by step guide. It's stated that A/P should disconnect at MAP altitude, and also it should disconnect at 50 ft below that if not before. But this doesn't happen. I tried with the three NPA modes (man/man, man/sel, sel/sel) and with copilot on and off.. without success.

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9 minutes ago, Alessio75 said:

Hi,

I'm studying NPA on A320 v1.31 (FsxSp2) following the step by step guide. It's stated that A/P should disconnect at MAP altitude, and also it should disconnect at 50 ft below that if not before. But this doesn't happen. I tried with the three NPA modes (man/man, man/sel, sel/sel) and with copilot on and off.. without success.

 

Okay,  you had me going a little regarding the MAP (which is Missed Approach Point/Procedure).   I see what you're asking about, it's actually the MDA (Minimum Decision Altitude) or MDH (Minimum Decision Height).

 

First thing first... let's ensure we know what the MDA/MDH are (I'll now refer to them as DA an DH and the term "minimum" is fairly redundant for our purpose here).

 

Without going into too much detail, Decision Altitude is based on Barometric Pressure while Decision Height is based on the altitude determined by the Radio Altimeter.  There are different reasons for why one might select DA or DH, but generally speaking for flight sim purposes DH is going to be the more accurate of the two (you'd think this  true real world, but it's not necessarily true).  For more in depth knowledge of Decision Altitude verse Decision Height and how to read these values on a Chart (yeah, you'll need to do this) see THIS LINK, or the SkyBrary Link, or you can download an excellent PDF on the subject.  Please, at a minimum do take the time to read all the information at the first link, it's stuff you really need to know for flight sim at this level.

 

Anyway, to answer  your question, you need to disable the Autopilot at 50ft.  It won't happen automatically.

 

I hope this answers your question!

 

Best wishes.

 

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Hi, thank you. Ok I need to disconnect  AP manually, but in the paragraph 7.12 of the step by step guide I can read that "Failure to disconnect AP by MDA will result in automatic AP disconnection at MDA-50 ft". 

So I am confused about

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23 minutes ago, Alessio75 said:

Hi, thank you. Ok I need to disconnect  AP manually, but in the paragraph 7.12 of the step by step guide I can read that "Failure to disconnect AP by MDA will result in automatic AP disconnection at MDA-50 ft". 

So I am confused about

How the Airbus reacts IRL depends on the Softwareversion of the FWC.

In this addon it was modeled as follow:

1. Pilot has to disconnect MANUALLY at MDA

2. If the pilot don’t disconnect, the Airbus disconnects automatically at MDA-50ft

 

In the newer Airbus Professional Addon for P3Dv4 we modeled a more modern Version of the FWC:

1. Pilot has to disconnect MANUALLY at MDA

2. If the pilot doesn’t disconnect, there will be only a message in the FMA at MDA-50ft, requesting the manual disconnection.

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15 minutes ago, masterhawk said:

How the Airbus reacts IRL depends on the Softwareversion of the FWC.

In this addon it was modeled as follow:

1. Pilot has to disconnect MANUALLY at MDA

2. If the pilot don’t disconnect, the Airbus disconnects automatically at MDA-50ft

 

In the newer Airbus Professional Addon for P3Dv4 we modeled a more modern Version of the FWC:

1. Pilot has to disconnect MANUALLY at MDA

2. If the pilot doesn’t disconnect, there will be only a message in the FMA at MDA-50ft, requesting the manual disconnection.

 

Thanks, ok so may I have a bug? If I don't disconnect, it doesn't itself at MDA-50ft.

In my A320 v1.31

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1 hour ago, masterhawk said:

2. If the pilot don’t disconnect, the Airbus disconnects automatically at MDA-50ft

 

Interesting!  I didn't remember that!  I could have sworn it didn't.

 

Maybe he didn't program the DA/DH (which I presume could cause it not to auto disconnect).

 

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42 minutes ago, DaveCT2003 said:

 

Interesting!  I didn't remember that!  I could have sworn it didn't.

 

Maybe he didn't program the DA/DH (which I presume could cause it not to auto disconnect).

 

I insert the baro or radio value in the MCDU page, is it the right place? 

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44 minutes ago, Alessio75 said:

I insert the baro or radio value in the MCDU page, is it the right place? 

 

Yes sir, in the Perf/Approach page. You can pull the info from the Approach Plate (Chart).

 

 

 

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On 4/21/2020 at 12:01 AM, masterhawk said:

How the Airbus reacts IRL depends on the Softwareversion of the FWC.

In the newer Airbus Professional Addon for P3Dv4 we modeled a more modern Version of the FWC:

1. Pilot has to disconnect MANUALLY at MDA

 

 

Hi,

I fully agree with that, but let me ask a question:

Can someone advice me how to program a switch on the joystick for disconnecting the AP using FSUIPC? I was trying different options with no success till moment.

Thank you!

 

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1 hour ago, Alessio75 said:

Need I to leave the FD button on? In off position I don't have the birdie on PFD

 

FLYING REFERENCE
It is recommended to use the FD crossbars for approach using vertical managed guidance (FINAL
APP). The FPV (also called "bird") with FPD is used for approach using FPA guidance (LOC FPA,
NAV FPA and TRK FPA).

 

I believe the Flight Directors will automatically be disabled if no AP is on, which you'd be turning them off at 50' on your NPA.

 

 

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2 hours ago, Alessio75 said:

Need I to leave the FD button on? In off position I don't have the birdie on PFD

 

You'd leave the FD on as long as it gives good information. When it does not give you useful information (for instance if there's no runway waypoint in the FMC). Otherwise you'd leave them ON; unless you want to turn them off.

If you *want* to turn the FD's off to practice raw data flying you can do so at all time when you want.

 

The Bird is available with both FD ON and OFF. If you're flying an NPA it can be good practice to turn it on to monitor the flight path angle. It is not mandatory however, but simply good practice.

 

22 hours ago, Goshob said:

 

Hi,

I fully agree with that, but let me ask a question:

Can someone advice me how to program a switch on the joystick for disconnecting the AP using FSUIPC? I was trying different options with no success till moment.

Thank you!

 

 

I assigned FSUIPC to send a keyboard command and then use the default Z key for it. Please open your own topic and don't hijack others though.

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19 hours ago, Emanuel Hagen said:

 

You'd leave the FD on as long as it gives good information. When it does not give you useful information (for instance if there's no runway waypoint in the FMC). Otherwise you'd leave them ON; unless you want to turn them off.

If you *want* to turn the FD's off to practice raw data flying you can do so at all time when you want.

 

The Bird is available with both FD ON and OFF. If you're flying an NPA it can be good practice to turn it on to monitor the flight path angle. It is not mandatory however, but simply good practice.

 

 

I assigned FSUIPC to send a keyboard command and then use the default Z key for it. Please open your own topic and don't hijack others though.

Thank you!

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