Rings on Approach Plates

Stan Prevost

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Mar 31, 2001, 11:19:23 PM3/31/01

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Hi, y'all -

I've been helping a friend study for his instrument orals. A couple of
things came up that I don't know. We are using FAA charts, not Jepp.

1. What is the 10 nm ring centered on? Does the chartmaker just move it
around however works best to be able to depict the important stuff to scale
within the ring?

2. I can find no description of feeder facility rings and enroute facility
rings, and the various plates I have examined have not given up their
secrets. Where I have seen facilities or fixes shown on the feeder ring,
they are in the enroute structure (on airways), just like the ones shown on
the enroute ring. Missed approach points are shown on both rings. Anyone
have a good description? An example plate in my area is Birmingham
International in Alabama. Some airports show only the enroute ring, some
only the 10 nm ring, some no rings. Does airport size or class determine
what is shown, or what?

Stan

Gus Elterman

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Apr 1, 2001, 1:08:37 AM4/1/01

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Your problem although well intentioned is: You are not a CFI.
Alabama pilots could somehow, someday venture across state lines.

Stan Prevost

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Apr 1, 2001, 1:58:15 AM4/1/01

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No, we are not allowed to do that, even if we could figure out how.

"Gus Elterman" <elte...@hotmail.com> wrote in message
news:3AC6C5...@hotmail.com...

Marcelo Pacheco

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Apr 1, 2001, 5:08:08 PM4/1/01

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Stan Prevost wrote:
>
> Hi, y'all -
>
> I've been helping a friend study for his instrument orals. A couple of
> things came up that I don't know. We are using FAA charts, not Jepp.
>
> 1. What is the 10 nm ring centered on? Does the chartmaker just move it
> around however works best to be able to depict the important stuff to scale
> within the ring?

Interesting question, not something that need to be known to be an instrument
pilot. Browsing through FL aproach plates, the 10nm ring is centered on the FAF
mostly, when the FAF isn't a fix (for example, when there's no charted
transition that avoids a procedure turn), it's the IAF, standalone GPS
procedures don't seem to have it at all.

> 2. I can find no description of feeder facility rings and enroute facility
> rings, and the various plates I have examined have not given up their
> secrets. Where I have seen facilities or fixes shown on the feeder ring,
> they are in the enroute structure (on airways), just like the ones shown on
> the enroute ring. Missed approach points are shown on both rings. Anyone
> have a good description? An example plate in my area is Birmingham
> International in Alabama. Some airports show only the enroute ring, some
> only the 10 nm ring, some no rings. Does airport size or class determine
> what is shown, or what?

Enroute facilities mean that all fixes that will be shown in low/high altitude
enroute charts, while feeders won't necessarily.

> Stan

Marcelo Pacheco
PP-ASEL IFR

Dan Luke

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Apr 2, 2001, 1:13:54 PM4/2/01

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"Stan Prevost" wrote:
> No, we are not allowed to do that, even if we could figure out how.

You just have to know what to say to ATC. Example:

"Houston Center, Porterfield 123AL, 5 miles on the Brookley 27 radial,
request permission to leave the Class GB (Goober) airspace, destination New
Orleans Lakefront."

"Porterfield 123AL, Houston Center. Squawk 7100 and verify you have had your
shots."

"Porterfield 123AL, affirmative Foot-and-Mouth and Swine Flu. Unable squawk
but I do have aluminum foil wrapped around my wing struts."

"Porterfield 123AL primary radar contact. Cleared out of the Class Goober
airspace. Maintain one thousand one hundred..."

It's easy if you know how. Just be sure to be back across the state line
before midnight local.

Dan
N9387D at BFM

Jim Fisher

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Apr 2, 2001, 2:36:15 PM4/2/01

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"Dan Luke" <walters_...@hotmail.com> wrote in message

> "Porterfield 123AL, Houston Center. Squawk 7100 and verify you have had
your
> shots."
>
> "Porterfield 123AL, affirmative Foot-and-Mouth and Swine Flu. Unable
squawk
> but I do have aluminum foil wrapped around my wing struts."

Guffaw!

--
Jim Fisher
North Alabama
Cherokee 180

Ben Bothma

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Apr 11, 2001, 2:11:19 PM4/11/01

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Hi Stan, herewith some info from Kershner: The Instrument Flight Manual
which may help,

> 1. What is the 10 nm ring centered on? Does the chartmaker just move it
> around however works best to be able to depict the important stuff to
scale
> within the ring?

According to the book: "The radio aid to navigation for the final part of
the instrument approach is positioned in the center of the inner ring." Note
that this can also be a fix e.g. DICKY HYK 12 DME, all very confusing, note
that it is not allways the FAF. The center can therefore be different for
different approaches to the same runway.

> 2. I can find no description of feeder facility rings and enroute
facility
> rings, and the various plates I have examined have not given up their
> secrets. Where I have seen facilities or fixes shown on the feeder ring,
> they are in the enroute structure (on airways), just like the ones shown
on
> the enroute ring. Missed approach points are shown on both rings. Anyone
> have a good description? An example plate in my area is Birmingham
> International in Alabama. Some airports show only the enroute ring, some
> only the 10 nm ring, some no rings. Does airport size or class determine
> what is shown, or what?

Not all approach charts have feeder facilities. Feeder facilities are used
by ATC to direct you from the route structure to the IAF. Also not all
charts show the en route facilities, some charts without en-route/feeder may
say "Radar Required" or Radar and DME Required".
My own deduction is basically that the larger the facility, the more fixes
and routes are required to seperate all aircraft converging on the airport.
I don't know of a rule as such, maybe someone else can help.

Cheers
Ben