Why the "Y" in Alaska?

[StaticWick]

This is coming from a lower 48 state pilot so be nice:

On the Jeppesen Kodiak, Alaska, ILS Y RWY 25 Approach plate why the "Y"?

This seems to be only Alaska specific but I could be wrong. A buddy was going in there with current charts and the controller issued a different letter on the same plate and he was asking me the question since I was a fomer CFII...I graceful said, "The $%# if I know...but I know where to find out on the weekend."

Thanks,
SW

 

[propsarebest]

Some operators are approved for the same ILS, but with different mins, eg ILS Z in MFR.

 

[StaticWick]

so the letters correspond to different minimums...

 

[MauleSkinner]

I can't find a reference, my understanding is that letters beginning at the end of the alphabet (Z,Y,X...) indicate that multiple versions of the same approach are available. While the ILS Z isn't available as a public approach, it may be privately created and held by an air carrier, with lower minimums and special training requirements under the air carrier's training program and Ops Specs.

Fly safe!

David

 

[A Squared]

I can't find a reference, my understanding is that letters beginning at the end of the alphabet (Z,Y,X...) indicate that multiple versions of the same approach are available. While the ILS Z isn't available as a public approach, it may be privately created and held by an air carrier, with lower minimums and special training requirements under the air carrier's training program and Ops Specs.

Fly safe!

David

Maule skinner is correct.

I believe that the reference may be in the AIM, I may be mistaken. If it's not in the AIM, It's in the TERPS.

Anbyway, it is not specific to Alaska, but any time you have more than one straight in approach using the same navaid, they are given letters starting with Z and progressing backward, in order to give them a unique name. It has nothing to do with whetehr the approach is public or priveate. I can think of at least one airport which has an ILS Z and ILS Y, both to the same runway, both using the same LOC freq. and both public approaches published in the NACO plates. At this particular airport, there are two ILS procedures for the same runway because one if designed to transition from the VHF airways and the other designedned to transition from the colored airway routes.

 

[FL420]

The answer can be found in Chapter 5 of the Instrument Procedures Handbook, FAA-H-8261-1 excerpted below:

APPROACH CHART NAMING CONVENTIONS​

Individual NACO charts are identified on both the top and the bottom of the page by their procedure name (based on the NAVAIDs required for the final
approach), runway served, and airport location. The identifier for the airport is also listed immediately after the airport name, as shown in figure 5-4.

There are several types of approach procedures that may cause some confusion for flight crews unfamiliar with the naming conventions. Although specific information about each type of approach will be covered later in this chapter, here are a few procedure names that can cause confusion.​

STRAIGHT-IN PROCEDURES​

When two or more straight-in approaches with the same type of guidance exist for a runway, a letter suffix is added to the title of the approach so that it can be more easily identified. These approach charts start with the letter Z and continue in reverse alphabetical order. For example, consider
the RNAV (GPS) Z RWY 10R and RNAV (GPS) Y RWY 10R approaches at San Francisco International Airport. [Figure 5-5] These two approaches to the same runway are slightly different, one includes an intermediate step-down fix and the other does not; and one allows the use of vertical navigation (VNAV) and the other does not. In order to differentiate the approaches, the
FAA has labeled them Z and Y. This convention also eliminates any confusion with approach procedures labeled A and B, where only circling minimums
are published. The designation of two area navigation (RNAV) procedures to the same runway can occur when it is desirable to accommodate panel mounted global positioning system (GPS) receivers and flight management systems (FMSs), both with and without VNAV. It is also important to note that only one of each type of approach for a runway, including ILS, VHF
omnidirectional range (VOR), non-directional beacon (NDB), etc., can be coded into a database.​

CIRCLING ONLY PROCEDURES​

Approaches that do not have straight-in landing minimums are identified by the type of approach followed by a letter. Examples in figure 5-6 show
four procedure titles at the same airport that have only circling minimums.
As can be seen from the example, the first approach of this type created at the airport will be labeled with the letter A, and the lettering will continue in alphabetical order. Circling-only approaches are normally designed
for one of the following reasons:
• The final approach course alignment with the runway centerline exceeds 30º.
• The descent gradient is greater than 400 feet per NM from the FAF to the threshold crossing height (TCH).

When this maximum gradient is exceeded, the circling only approach procedure may be designed to meet the gradient criteria limits. This does not preclude a straight-in landing if a normal descent and landing can be made in accordance with the applicable CFRs.​

 

[StaticWick]

Thanks for digging the answer up FL420....I'll pin a gold star on your attendance sheet.