ILS Suffix such as xyz

[vinayak]

Couldn't find what the mean....


When i look at the charts seems like the initial approach segment is different. Such as in Bangalore.

Mumbai seems to have an arc for one of them.... What is the difference? which one do I pull out to follow when I'm just doing a normal radar vectored approach....


thanks,

[hetfield]

Yeah, different procuders ILS 1, 2 etc.

Should be stated on ATIS which one is in force otherwise I would confirm with ATC even if vectored `cause sometimes missed approach differs as well.

[bfisk]

At my home field we have an ILS-z and an ILS-y. The difference in that case is the missed approach procedure, the z being the primary with the VOR hold, and the y has and off-field NDB hold in case the VOR is unservicable.

[downwindabeam]

Just like the guys said, different names to distinguish different procedures.

In Detroit, Michigan we have an ILS Zulu and ILS Yankee (ILS-z, ILS-y) for each of the outboard runways.

One is the straight in ILS and one is the 1 degree offset ILS to be used when they start using PRM approaches on the adjacent runways.

[JockMcToff]

Answer copied below from ICAO Doc 8168:

8.5.1.3 Duplicate procedure identification

8.5.1.3.1 A single letter suffix, starting with the letter Z, following the radio navigation aid type shall be used if two or more procedures to the same runway cannot be distinguished by the radio navigation aid type only. For example:

VOR Z Rwy 20
VOR Y Rwy 20

8.5.1.3.2 The single letter suffix shall be used as follows:

a) when two or more navigation aids of the same type are used to support different approaches to the same runway;

b) when two or more missed approaches are associated with a common approach, each approach shall be identified by a single letter suffix;

c) if different approach procedures using the same radio navigation type are provided for different aircraft categories; and

d) if two or more arrivals are used to a common approach and are published on different charts, each approach shall be identified by a single letter suffix. If additional radio navigation aids are required for the arrival, they
shall be specified on the chart’s plan view. For example:

ILS Z RWY 20 (“DNA VOR Arrival” shown in the plan view)
ILS Y RWY 20 (“CAB VOR Arrival” shown in the plan view)


:8

[Bullethead]

G'day vinayak,

As well as the info in JockMcToff's post sometimes the difference between two procedures is simply the DME being used, i.e. the ILS DME or an associated VOR/DME for the same ILS approach.

Regards,
BH.