Question about Approach Plates

[Russ MacDonald]

One of my students asked me a question the other day that I have been unable
to answer.

Many instrument approaches are labeled with a letter following the primary
name and the letter indicates that the final approach course is not lined up
(beyond 30 degrees) with any runway, and that a circling approach is
required. For example: VOR-A.

That said, what is the difference between VOR-A, VOR-B, VOR-C, etc? Does
the letter have any additional significance? Why, at some airports is there
a VOR-B or VOR-C but no VOR-A? Is it because there used to be a VOR-A and
it was decommissioned?

Thanks,

Russ MacDonald, CFII

[Stan Prevost]

The "A " suffix is applied to the first approach generated for that city
name. "B" is for the second approach for that city name. It is not by
airport, but by city name.


"Russ MacDonald" > wrote in message
news:tJV6f.11984$gF4.4699@trnddc07...
> One of my students asked me a question the other day that I have been
> unable to answer.
>
> Many instrument approaches are labeled with a letter following the primary
> name and the letter indicates that the final approach course is not lined
> up (beyond 30 degrees) with any runway, and that a circling approach is
> required. For example: VOR-A.
>
> That said, what is the difference between VOR-A, VOR-B, VOR-C, etc? Does
> the letter have any additional significance? Why, at some airports is
> there a VOR-B or VOR-C but no VOR-A? Is it because there used to be a
> VOR-A and it was decommissioned?
>
> Thanks,
>
> Russ MacDonald, CFII
>

[Roy Smith]

In article <tJV6f.11984$gF4.4699@trnddc07>,
"Russ MacDonald" > wrote:

> One of my students asked me a question the other day that I have been unable
> to answer.
>
> Many instrument approaches are labeled with a letter following the primary
> name and the letter indicates that the final approach course is not lined up
> (beyond 30 degrees) with any runway, and that a circling approach is
> required. For example: VOR-A.
>
> That said, what is the difference between VOR-A, VOR-B, VOR-C, etc? Does
> the letter have any additional significance? Why, at some airports is there
> a VOR-B or VOR-C but no VOR-A? Is it because there used to be a VOR-A and
> it was decommissioned?

There is no significance other than the order the approaches were first
published. They start at A for the first circling approach at an airport,
and work their way through the alphabet. Some airports have a bunch of
them; LGA has an LDA-A, VOR/DME-E, VOR-F, VOR-DME/G, and VOR-DME/H.
Presumably at some time there were B, C, and D approaches which have since
been revoked.

BTW, it's not just mis-alignment between the FAC and the runway. An
approach will also not get straight-in minimums if the descent profile is
too steep (IIRC, 400 ft/nm). Compare and contrast, for example, the VOR-A
and the VOR/DME-24 at POU. Exactly the same FAC, but the DME approach gets
you a couple hundred feet lower at the FAF, so it qualifies for straight-in.

[[email protected]]

Roy Smith wrote:

>
> approach will also not get straight-in minimums if the descent profile is
> too steep (IIRC, 400 ft/nm).

Correct, except for CAT D, the limit is 350 feet per mile. (Used to be 400 like
A,B, and C.)

[Steven P. McNicoll]

"Russ MacDonald" > wrote in message
news:tJV6f.11984$gF4.4699@trnddc07...
>
> One of my students asked me a question the other day that I have been
> unable to answer.
>
> Many instrument approaches are labeled with a letter following the primary
> name and the letter indicates that the final approach course is not lined
> up (beyond 30 degrees) with any runway, and that a circling approach is
> required. For example: VOR-A.
>

It's not just the alignment of the FAC, if the approach gradient is too
steep or the runway is indistinct there will be no straight-in minima.


>
> That said, what is the difference between VOR-A, VOR-B, VOR-C, etc? Does
> the letter have any additional significance? Why, at some airports is
> there a VOR-B or VOR-C but no VOR-A? Is it because there used to be a
> VOR-A and it was decommissioned?
>

The alphabetical suffix for circling procedures is not duplicated at
airports with identical city names within the same state.

[Randy]

OK maybe somebody can answer this one...on the NOAA plates near the top
of the page there is a little three or four digit number that
corresponds to the airport...anybody know where I can find a list of
airport names that match the numbers?