Hi fellas! I have flown for a while at Stockholm Arlanda (ESSA) and have never seen ILS Y and ILS Z before in the FMC. For example, runway 01L have both Y and Z as an option on approach. I can remember from somewhere that Z uses a lower DA then the Y approach. By studing some charts i cant see any difference. Anyway, i do not know if this is true and if anyone knows what difference is i would appreciate if you shared your information with me :) ILS Z chart: http://www.lfv.se/AI...ESSA_5_1_en.pdfILS Y chart: http://www.lfv.se/AI...ESSA_5_2_en.pdf

For one thing, if you want to/have to fly the full approach with the hold, you need an ADF+DME (and HSI or VOR indicator for the ILS, of course) for the ILS Y. You need only VOR+DME for Z.

Hi Anton, One of them requires the VOR to operative (Z). The other requires the NDB to be operative (Y). Look at the holding pattern/race track. And you don't need GPS/RNAV to fly either of them. regards

Yeah, Martin's right. I misspoke about GPS/RNAV. When I looked at the chart quickly, I thought that was a RNAV waypoint at ARL.

okey, thanks! :)

The Y and Z suffixes are a 'rule of thumb' by ICAO. It just tells you there are differences between the procedures, either in terms of tracks or equipment needed. If there are more than one of the sames type proc down that runway, the procedure will have a Z then a Y then X and so on ...So, if u see a Y procedure but cannot find a Z procedure, then something shud be amiss.

Hi Anton, One of them requires the VOR to operative (Z). The other requires the NDB to be operative (Y). Look at the holding pattern/race track. And you don't need GPS/RNAV to fly either of them. regards

Thanks! Finally you have an answer to my doubts.