744 Forum

Apron => Hangar 7 => Topic started by: JohnH on Sun, 17 Mar 2019 13:25

Title: CYYZ runway 05 ILS error
Post by: JohnH on Sun, 17 Mar 2019 13:25
Hi Hardy,

Sometimes (not always) when flying into CYYZ runway 05 the ILS tunes to 109.70/051. Other times it tunes the correct ILS as 109.70/057

It only seems to happen with runway 05, all the others seem ok.

Attached is a situ file if that helps. I am using v10.71 and the most recent navdata 1903

https://www.dropbox.com/s/k6gflzrf2dzzvnf/CYYZ%2005%20ILS%20error.situ?dl=0

John
Title: Re: CYYZ runway 05 ILS error
Post by: Hardy Heinlin on Sun, 17 Mar 2019 14:33
Hi John,

I always get the correct 057 course.

What do I have to do to get a chance to reproduce the problem?


|-|ardy


When you start your CYYZ scenario, do you load a specific situ file that has been saved some years ago?
Title: Re: CYYZ runway 05 ILS error
Post by: JohnH on Sun, 17 Mar 2019 16:40
Yes the 'situ' file is quite old probably 3 yrs. I am going to create a new situ from scratch and see if the solves the issue.

Thankyou John

Title: Re: CYYZ runway 05 ILS error
Post by: Hardy Heinlin on Sun, 17 Mar 2019 16:57
How far has the magnetic variation at CYYZ been drifting since then?

I guess you load outdated NAV RAD data with your old situ file, and until the ILS is autotuned later in cruise, you won't see any tuning update based on the new database.

There are 3 ILS receivers on the aircraft, and they store the ILS data that is set in the FMCs and CDUs. The FMCs and CDUs may fail; it won't matter: the receivers keep their last setting in their memory. And that memory is stored in the situ files.
Title: Re: CYYZ runway 05 ILS error
Post by: JohnH on Sun, 17 Mar 2019 17:10
I recently had to replace my hard drive so had to re-install PSX from the original disk and update all the files. I then copied my CYYZ file from my usb stick so it is very old. That probably is the issue.

John
Title: Re: CYYZ runway 05 ILS error
Post by: JohnH on Sun, 17 Mar 2019 19:11
After creating a new situ file using the PSX cold and dark situ everything seems perfect!! Only thingI can't find is the PSX icon for iMac, using search can only find the windows icon?

Thanks again! John
Title: Re: CYYZ runway 05 ILS error
Post by: Britjet on Mon, 18 Mar 2019 09:59
Sorry to butt in here, Hardy -but could you just clarify what you lose if you have an old saved file?
I have loads of these - if I don't save again then what am I missing?
Also - I save in two ways - one is by saving the situ on the IOS, and the other is by pressing the Event Record button. I know there is a difference with time etc, but are there other subtleties?

Thanks!

Peter
Title: Re: CYYZ runway 05 ILS error
Post by: Hardy Heinlin on Mon, 18 Mar 2019 11:10
Two things change from year to year:

(1) Global magnetic variation database, updated by installing the latest PSX version.

(2) Global nav database, updated by installing the latest Aerowinx Nav Database.

Both refer to the same year. Users that have the latest Nav Database should also use the latest PSX version and vice versa. It's not a requirement in the sense that the aircraft will fall from the sky, but it will make the numbers more accurate.

The 3rd thing is the data stored in situation files; that stored data may get outdated when (1) and (2) progress. This includes the frequency settings in the receivers: VHF L, C, R; VOR L & R; ADF L & R; MMR (ILS) L, C, R (including front course).

E.g. when you load an old situ file that is supposed to run an ATIS voice loop, and the related ATIS frequency is no longer valid due to a nav database update, you need to retune the frequency accordingly and resave the situ file.

Similar problems may occur when navaids are manually tuned, or autotuning is enabled but not running yet. If manually tuned, outdated frequencies are loaded, you should retune them and resave the situ file.

ILS tunings include the localizer course. For this all of the above three "things" should agree: Magnetic variation, nav database, situ file. The situ file part, however, will resolve itself when autotuning starts.

But the accuracy of the localizer course is not that essential. It's just used for this:

1. AFDS LOC capture criterium; it must be within 120° of aircraft track (a very large angle).
2. PVD capture criterium; it must be within 45° of aircraft track (that's a lot too).
3. Text label on PFD for reference in manual flight (AFDS guidance won't care; it refers to the IRS track)
4. AFDS MCP HDG bug autosetting
5. ND APP display CDI setting

In other words, autoland will land normally as usual.


Regards,

|-|ardy


It doesn't matter whether the situ is stored by the Save button or by the Event Record button. The Event Record button just disables the real-time weather download mode in the stored situ so that reloading this situ accurately reproduces this event. The Save button, however, keeps the current weather mode intact; so when reloading that situ the weather may promptly change to the current real-world weather. But this has nothing to do with the stuff mentioned above.
Title: Re: CYYZ runway 05 ILS error
Post by: Britjet on Mon, 18 Mar 2019 20:46
Hardy - thanks for the detailed reply. Much appreciated..
Peter