744 Forum

Apron => Hangar 7 => Topic started by: Hardy Heinlin on Wed, 22 Dec 2021 16:08

Title: Nav databases shown on the FMC IDENT page
Post by: Hardy Heinlin on Wed, 22 Dec 2021 16:08
Users coming from other simulator products sometimes ask why the FMC IDENT page in PSX doesn't indicate the date of the sim's current general database.

It's a feature. The FMC IDENT page in PSX refers to the simulated time set on Instructor > Situation > Time (the setting is stored in situ files; when you load a different situ file, you may see different IDENT page values). This logic is intentional and designed for sim training; you can swap and check cycles on the IDENT page, and this action will never change the sim's actual database which is indicated on Instructor > About. Actions in the FMC will never change any facilities on the sim's planet (radio stations, runways, gates etc. on the sim's planet are also loaded from the current database; the FMC stuff is just a fraction of the database package).

In short words: Select your database on Instructor > About. -- That's it. -- Don't care about the IDENT page.

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Well, if you want to play with the IDENT page anyway, here's the background:

In PSX there is another special feature. On Instructor > Situation > Service, in the upper left corner, find the checkbox "Select valid FMC nav database".

What will happen when this checkbox is selected?

The two database dates on the IDENT page always refer to the simulated time set on Instructor > Situation > Time. PSX includes a virtual engineer that always activates the correct one of the two databases in the FMC when the aircraft is parked. That is, the inactive one will always be the last outdated one or -- when close to the next cycle -- the next database. When the user swaps the databases (e.g. to clear all FMC entries) and the active date now disagrees with the sim's current planet time, the virtual engineer will swap them again after a few seconds.

What will happen when the checkbox is deselected?

As usual, the inactive date on the IDENT page will always be the last outdated one or -- when close to the next cycle -- the next database, referring to the simulated time set on Instructor > Situation > Time. When the user swaps the databases (e.g. to clear all FMC entries) and the active date now disagrees with the sim's current planet time, the virtual engineer will do nothing. So when the selected active date disagrees with the sim's planet time, the FMC message NAV DATA OUT OF DATE will appear.

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How can I create a situation file that will require the pilot to select the active database on the IDENT page?

Example:

1. Load an on-ground situ file

2. On Service page, select the checkbox "Select valid FMC nav database"

3. On Time page set the season slider to AUG

4. IDENT now has 2 cycles for the time around AUG

5. On Service page, deselect the checkbox "Select valid FMC nav database"

6. On Time page move the season slider forward to OCT

7. IDENT now has an inactive database for OCT, and the active is still for AUG

8. The message NAV DATA OUT OF DATE appears

9. Save this situation

In this situation the pilot can swap the cycles manually on the IDENT page, and the selected active one will stay. The time slider will just change the inactive one.

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Regards,

|-|ardy