Deleting a tuned ILS: need to do it twice?

[Will]

If you have a moment, you might give this a try:

Start PSX
Load Basic 027 - Parked and ready for engine shutdown
Select NAV RAD page
Press DELETE, then press 4L (over the auto-tuned ILS frequency)
Note that the frequency and course are replaced by PARK
Note that the ILS frequency and course, and CDIs, remain visible on the PFDs (Observation #1)
Press Delete, then press 4L (over the word "PARK")
Now three things happen:
   1. PARK is replaced by the course and frequency for a few milliseconds
   2. The course and frequency are replaced by PARK again
   3. The course, frequency, and CDIs disappear from the PFDs.
Now reload Basic 027
Select NAV RAD page
Note that the ILS is still parked (Observation #2)
Now load Basic 026 - Taxying to gate
Note that the ILS is still parked

Observation #1: You have to DELETE the frequency twice to remove the display on the NDs. Is that accurate?

Observation #2: Removing the ILS is durable, even after loading other situs; PARK it in one situ, and it still appears parked when that situ is freshly loaded.

(I noticed this when flying my own situs. Using Basic 027 is just a common reference point to demonstrate the observations.)

Thanks.

[Hardy Heinlin]

There was a PSX update in 2022:

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Version 10.158 - 20 November 2022

158.11. FMC: Manual deletion of autotuned ILS is now valid; it will change to parked mode (which can be reset by another deletion or by executing a MOD).
------------------------------------------------------

I can't remember how the "Basic 027" situ would behave regarding that mod. These "Basic" situs have been saved in 2014, and since then there were some modifications in the ILS delete functions. Can you reproduce your observations with situs that were saved in PSX version 10.158 or higher?

Anyway, if it refers to mod 158.11 then it's intentional. I think I got that hint for this mod from Captain Al.


Regards,

|-|ardy

[Will]

Hardy, I saw that thread from Captain Al when I was searching for this on the forum. The issue I'm asking about is not simply deleting the frequency.

It's that deleting the frequency only changes the display on the MCDU; the PFDs still display the ILS data, until you go to the FMC again and delete the word "PARK".

The first delete removes the frequency from 4L, and you need to delete it again to remove the data from the flight instruments. Before you do the second step, you have the MCDU saying PARK while the PFD displays the ILS frequency, course, and CDI scales.

Is that the expected behavior?

Also, I am seeing this with situs I created last night; I only used the historical situ for ease in demonstrating the effect.

[Hardy Heinlin]

Start PSX
Load Basic 027 - Parked and ready for engine shutdown
Select NAV RAD page
Press DELETE, then press 4L (over the auto-tuned ILS frequency)

When I load that situ, PARK is already displayed. I see no auto-tuned ILS frequency. Neither on the CDU nor on the PFD.

[Will]

Interesting. Keep in mind my observation #2 from the original post. If you PARK the ILS on one situ, it stays parked on other situs.

Try Basic 027 after a fresh restart of PSX.

[Hardy Heinlin]

I see. Well, reloading the situ file (ALT+S) will reset it to the actually saved situation data :-)