Sectional Chart Question

[Teranews]

A pilot recently asked me a question, that I cannot find the answer to.

On a sectional chart, around cities, are yellow areas.
What are they?
Where on the legend can this be found?

My answer was "congested areas of a city or town" which I though sounded
official
enough to work. Ah-Ha, he says, "Show me."

The specific area in question is just south of Sunriver, on the Klamath
Falls sectional. (DSD 175 @ about 25nm) I've flown over it, and it is a
combination of golf courses.

Over beer last night, one fellow suggested that it is marked that way
for "National Security Reasons".
Wink, Wink, nudge, nudge, "You are not supposed to ask.", "Why do you think
they left it off the legend."

Am I just blind? Is the print too small? Can anyone else find it on
the legend?

Al Gerharter

[Roy Smith]

Teranews > wrote:
>On a sectional chart, around cities, are yellow areas.
> What are they?
> Where on the legend can this be found?
>
>My answer was "congested areas of a city or town"

Close, They're supposed to be areas which are lit up at night.

>The specific area in question is just south of Sunriver, on the Klamath
>Falls sectional. (DSD 175 @ about 25nm) I've flown over it, and it is a
>combination of golf courses.

Golf courses lit up for night golf???

[Mark Hansen]

On 6/20/2005 12:30, Teranews wrote:

> A pilot recently asked me a question, that I cannot find the answer to.
>
> On a sectional chart, around cities, are yellow areas.
> What are they?
> Where on the legend can this be found?

These represent the congested parts of the cities. This should
(roughly) match the look of the city when lit up at night.

>
> My answer was "congested areas of a city or town" which I though sounded
> official
> enough to work. Ah-Ha, he says, "Show me."

Have him look in the Aeronautical Chart User's Guide (from NACO).
You can see it on line here:

<http://www.naco.faa.gov/index.asp?xml=naco/online/aero_guide>

Specifically, look in the section (PDF) titled "VFR Chart Symbols",
on page 19, under the entry titled "POPULATED PLACES OUTLINED".

>
> The specific area in question is just south of Sunriver, on the Klamath
> Falls sectional. (DSD 175 @ about 25nm) I've flown over it, and it is a
> combination of golf courses.
>
> Over beer last night, one fellow suggested that it is marked that way
> for "National Security Reasons".

No.

> Wink, Wink, nudge, nudge, "You are not supposed to ask.", "Why do you think
> they left it off the legend."

The legend don't cover everything. That's why they have the book.

If you don't have it yet, you should pick on up (you can get one at
most Pilot shops for around $5) and read it. It includes lots of
great information. Then you can ask your pilot friend a few questions
that he won't be able to answer ;-)

>
> Am I just blind? Is the print too small? Can anyone else find it on
> the legend?
>
> Al Gerharter
>
>
>


--
Mark Hansen, PP-ASEL, Instrument Student
Sacramento, CA

[Teranews]

So where did you find it?
Al



"Roy Smith" > wrote in message
...
> Teranews > wrote:
>>On a sectional chart, around cities, are yellow areas.
>> What are they?
>> Where on the legend can this be found?
>>
>>My answer was "congested areas of a city or town"
>
> Close, They're supposed to be areas which are lit up at night.
>
>>The specific area in question is just south of Sunriver, on the Klamath
>>Falls sectional. (DSD 175 @ about 25nm) I've flown over it, and it is a
>>combination of golf courses.
>
> Golf courses lit up for night golf???

[Teranews]

Thanks Mark, good shortcut. I'll get mine soon. Al


"Mark Hansen" > wrote in message
...
> On 6/20/2005 12:30, Teranews wrote:
>
>> A pilot recently asked me a question, that I cannot find the answer to.
>>
>> On a sectional chart, around cities, are yellow areas.
>> What are they?
>> Where on the legend can this be found?
>
> These represent the congested parts of the cities. This should
> (roughly) match the look of the city when lit up at night.
>
>>
>> My answer was "congested areas of a city or town" which I though sounded
>> official
>> enough to work. Ah-Ha, he says, "Show me."
>
> Have him look in the Aeronautical Chart User's Guide (from NACO).
> You can see it on line here:
>
> <http://www.naco.faa.gov/index.asp?xml=naco/online/aero_guide>
>
> Specifically, look in the section (PDF) titled "VFR Chart Symbols",
> on page 19, under the entry titled "POPULATED PLACES OUTLINED".
>
>>
>> The specific area in question is just south of Sunriver, on the Klamath
>> Falls sectional. (DSD 175 @ about 25nm) I've flown over it, and it is a
>> combination of golf courses.
>>
>> Over beer last night, one fellow suggested that it is marked that way
>> for "National Security Reasons".
>
> No.
>
>> Wink, Wink, nudge, nudge, "You are not supposed to ask.", "Why do you
>> think they left it off the legend."
>
> The legend don't cover everything. That's why they have the book.
>
> If you don't have it yet, you should pick on up (you can get one at
> most Pilot shops for around $5) and read it. It includes lots of
> great information. Then you can ask your pilot friend a few questions
> that he won't be able to answer ;-)
>
>>
>> Am I just blind? Is the print too small? Can anyone else find it on
>> the legend?
>>
>> Al Gerharter
>>
>>
>>
>
>
> --
> Mark Hansen, PP-ASEL, Instrument Student
> Sacramento, CA

[Bob Gardner]

I thought that it would make sense to look at the Aeronautical Chart Users
Guide, which is published for the specific purpose of answering questions
like this.

In the section "VFR Aeronautical Charts," under "Culture," we find that the
yellow areas represent "Cities and Large Towns," with a larger blotch of
yellow identified as "Large Cities." Nothing about lights or anything other
than population.

I tell my students to pay no attention to the boundaries of the yellow
blotches, because there is no way to identify city limits from the air, and
towns/cities simply change too fast for chart designations to make any
sense. The only practical use of the yellow blotches is, in my opinion, to
identify places where it is going to be difficult to find a place to land
(in-town airports excluded).

Bob Gardner

"Teranews" > wrote in message
news:1119295818.456e1bd0d1dc4312bea6e25f65e9e825@t eranews...
>A pilot recently asked me a question, that I cannot find the answer to.
>
> On a sectional chart, around cities, are yellow areas.
> What are they?
> Where on the legend can this be found?
>
> My answer was "congested areas of a city or town" which I though sounded
> official
> enough to work. Ah-Ha, he says, "Show me."
>
> The specific area in question is just south of Sunriver, on the Klamath
> Falls sectional. (DSD 175 @ about 25nm) I've flown over it, and it is a
> combination of golf courses.
>
> Over beer last night, one fellow suggested that it is marked that way
> for "National Security Reasons".
> Wink, Wink, nudge, nudge, "You are not supposed to ask.", "Why do you
> think they left it off the legend."
>
> Am I just blind? Is the print too small? Can anyone else find it on
> the legend?
>
> Al Gerharter
>
>
>

[Jose]

> On a sectional chart, around cities, are yellow areas.
> What are they?

Places they are too lazy to chart. :)

Actually, it's only half faceitous - in the yellow areas they do not
chart =anything= (except for a few towers), which makes it hard to use
for navigation. Even roads (which would be =excellent= landmarks at
night) are omitted.

/grouse

Jose
(r.a.student cut, as I don't follow that group)
--
My other car is up my nose.
for Email, make the obvious change in the address.

[Kev]

Bob Gardner wrote:
> In the section "VFR Aeronautical Charts," under "Culture," we find that the
> yellow areas represent "Cities and Large Towns," with a larger blotch of
> yellow identified as "Large Cities." Nothing about lights or anything other
> than population.

True, but they seem to follow the Army Field Manual on Topographic
Symbols:

b. Populated Places. A larger populated place is shown, generally true
to shape, by an outlined and [yellow] tinted area. Within the outline,
the only features usually shown are the mainline railroads and
through-route roads.

c. Use of Tinted Squares. In many areas, there is insufficient
information available to plot the correct outlines of populated places.
In such cases, tinted squares of varying sizes are used as symbols,
with the size depending upon the population or importance.

> I tell my students to pay no attention to the boundaries of the yellow
> blotches, because there is no way to identify city limits from the air, and
> towns/cities simply change too fast for chart designations to make any
> sense.

I dunno, some of the isolated smaller cities here in the Northeast do
have matching outlines at night. I've even matched up some outlines
during the day.

>The only practical use of the yellow blotches is, in my opinion, to
> identify places where it is going to be difficult to find a place to land
> (in-town airports excluded).

Now that's definitely good advice, and a great use of the outline!

Interestingly, I ran across an ultralight website where they described
the yellow outlines as being off-limits to them, because they're
obviously congested areas.

Best regards,
Kev

[Ben Hallert]

Without disagreeing, I'd like to chime in that when learning pilotage,
I found the outlined areas on the TAC for LA to be very helpful at
figuring out where I was with precision when all else failed. There
are a lot of 'water towers' and 'radio masts' and whatnot there, so
just because I'd find a likely looking landmark wouldn't mean I was
where I thought I was.

I had a hairy moment during my checkride trying to find an airport with
a half washed out runway near Camarillo (I think it was Santa Maria)
that the examiner wanted me to point out to him. The city outline
helped me do some triangulation when ye olde Mk I Eyeball initially
failed. Great examiner (GB should id him to the locals), not only did
it give me a real challenge to demonstrate pilotage (and as a result
'put up or shut up'), but he didn't give me an engine failure while I
was circling and looking, for which I'm grateful. :)

[Jimbob]

IIRC, The yellow represents areas under the FAR's which are
considered congested areas and require 1000' clearance within a 2000'
radius.





On Mon, 20 Jun 2005 12:30:08 -0700, "Teranews"
> wrote:

>A pilot recently asked me a question, that I cannot find the answer to.
>
>On a sectional chart, around cities, are yellow areas.
> What are they?
> Where on the legend can this be found?
>
>My answer was "congested areas of a city or town" which I though sounded
>official
>enough to work. Ah-Ha, he says, "Show me."
>
>The specific area in question is just south of Sunriver, on the Klamath
>Falls sectional. (DSD 175 @ about 25nm) I've flown over it, and it is a
>combination of golf courses.
>
> Over beer last night, one fellow suggested that it is marked that way
>for "National Security Reasons".
>Wink, Wink, nudge, nudge, "You are not supposed to ask.", "Why do you think
>they left it off the legend."
>
> Am I just blind? Is the print too small? Can anyone else find it on
>the legend?
>
> Al Gerharter
>
>

Jim

http://www.unconventional-wisdom.org

[Steven P. McNicoll]

"Jimbob" > wrote in message
...
>
> IIRC, The yellow represents areas under the FAR's which are
> considered congested areas and require 1000' clearance within a 2000'
> radius.
>

From what do you recall that?

[Dave Stadt]

\
"Jimbob" > wrote in message
...
> IIRC, The yellow represents areas under the FAR's which are
> considered congested areas and require 1000' clearance within a 2000'
> radius.

Well no. Don't think you can find any legal reference to support your
claim. If you compare the yellow on a sectional and a terminal area chart
they don't match.

[tony roberts]

> On a sectional chart, around cities, are yellow areas.
> What are they?
> Where on the legend can this be found?


"From the Ground Up" P:177

Communities, Roads, Railways
Yellow squares represent towns and small villages. Hamlets are
represented by small circles. A city is depicted by a yellow area
outlined in black that corresponds to the actual shape and size of the
community.

Tony

Tony Roberts
PP-ASEL
VFR OTT
Night
Cessna 172H C-GICE

[Cub Driver]

On Mon, 20 Jun 2005 12:40:40 -0700, Mark Hansen >
wrote:

>These represent the congested parts of the cities. This should
>(roughly) match the look of the city when lit up at night.

Amazing. Nobody ever told me that!

What would we do with newsgroups to consume our time and fill our
minds with facts?



-- all the best, Dan Ford

email (put Cubdriver in subject line)

Warbird's Forum: www.warbirdforum.com
Piper Cub Forum: www.pipercubforum.com
the blog: www.danford.net
In Search of Lost Time: www.readingproust.com

[Gary Drescher]

"Mark Hansen" > wrote in message
...
> On 6/20/2005 12:30, Teranews wrote:
>> On a sectional chart, around cities, are yellow areas.
>> What are they?
>> Where on the legend can this be found?
>
> These represent the congested parts of the cities. This should
> (roughly) match the look of the city when lit up at night.
> ...
> <http://www.naco.faa.gov/index.asp?xml=naco/online/aero_guide>

Useful pointer--thanks!

Note though that it refers to "populated" places, not "congested" places.
"Congested" has technical meaning in the FARs (regarding altitude rules),
and it's not clear whether "populated" means the same thing.

--Gary

[George Patterson]

Gary Drescher wrote:
>
> Note though that it refers to "populated" places, not "congested" places.
> "Congested" has technical meaning in the FARs (regarding altitude rules),
> and it's not clear whether "populated" means the same thing.

It doesn't. According to the local FAA, the beaches around here are congested
areas during the summer season. They aren't congested in the winter. Sandy Hook
during summer is an example of an unpopulated congested area.

George Patterson
Why do men's hearts beat faster, knees get weak, throats become dry,
and they think irrationally when a woman wears leather clothing?
Because she smells like a new truck.

[Gary Drescher]

"George Patterson" > wrote in message
news:IFUte.272$2s.101@trndny02...
> Gary Drescher wrote:
>>
>> Note though that it refers to "populated" places, not "congested" places.
>> "Congested" has technical meaning in the FARs (regarding altitude rules),
>> and it's not clear whether "populated" means the same thing.
>
> It doesn't. According to the local FAA, the beaches around here are
> congested areas during the summer season. They aren't congested in the
> winter. Sandy Hook during summer is an example of an unpopulated congested
> area.

Good point. I wonder though about the converse--are populated areas always
considered congested, or can there be (sparsely) populated areas that are
considered uncongested?

--Gary

[Mark Hansen]

On 6/21/2005 04:06, Gary Drescher wrote:

> "Mark Hansen" > wrote in message
> ...
>> On 6/20/2005 12:30, Teranews wrote:
>>> On a sectional chart, around cities, are yellow areas.
>>> What are they?
>>> Where on the legend can this be found?
>>
>> These represent the congested parts of the cities. This should
>> (roughly) match the look of the city when lit up at night.
>> ...
>> <http://www.naco.faa.gov/index.asp?xml=naco/online/aero_guide>
>
> Useful pointer--thanks!
>
> Note though that it refers to "populated" places, not "congested" places.
> "Congested" has technical meaning in the FARs (regarding altitude rules),
> and it's not clear whether "populated" means the same thing.

Yes ... I meant Populated, not congested.
Thanks for catching that.

>
> --Gary
>
>


--
Mark Hansen, PP-ASEL, Instrument Student
Sacramento, CA

[Mark Hansen]

On 6/21/2005 06:40, Gary Drescher wrote:

> "George Patterson" > wrote in message
> news:IFUte.272$2s.101@trndny02...
>> Gary Drescher wrote:
>>>
>>> Note though that it refers to "populated" places, not "congested" places.
>>> "Congested" has technical meaning in the FARs (regarding altitude rules),
>>> and it's not clear whether "populated" means the same thing.
>>
>> It doesn't. According to the local FAA, the beaches around here are
>> congested areas during the summer season. They aren't congested in the
>> winter. Sandy Hook during summer is an example of an unpopulated congested
>> area.
>
> Good point. I wonder though about the converse--are populated areas always
> considered congested, or can there be (sparsely) populated areas that are
> considered uncongested?

Well, the purpose of the detail on the chart is to provide visual cues
as to your location with respect to the populated area. Not (as far as
I know) to determine whether or not you are over a "congested" area.

However, when I was flying ultralights (which cannot be flown over
congested areas at all), my instructor would not let me fly over areas
depicted as populated on the sectional. I think he was going overboard,
but as a training rule, it was fine.

From what I've seen/read, what is or is not a congested area is not
defined well. Perhaps there are some 'legal interpretations' out there
that I've not seen yet.

>
> --Gary
>
>


--
Mark Hansen, PP-ASEL, Instrument Student
Sacramento, CA

[john smith]

Gary Drescher wrote:
> Good point. I wonder though about the converse--are populated areas always
> considered congested, or can there be (sparsely) populated areas that are
> considered uncongested?

Note that you will not find a definition of "congested" in any FAA
document. It is deliberately undefined to allow for broadly varying
enforcement.

[Mark Hansen]

On 6/20/2005 17:52, Kev wrote:

>
> Interestingly, I ran across an ultralight website where they described
> the yellow outlines as being off-limits to them, because they're
> obviously congested areas.

Obviosly congested? No... These are city/town areas, but they include
congested and non congested areas. The Ultralight club's rule is a good
rule of thumb, but it's not a FAR.

The thing about Ultralights is, they need to stay 'under the radar'
such that they don't raise a lot of complaints and invite extra
legislation prohibiting their use. So, rules like these keep them
well outside the 'problem areas'.

You can legally fly an ultralight through an area depicted in yellow
on the sectional, you just need to fly over only un-congested areas.

>
> Best regards,
> Kev
>


--
Mark Hansen, PP-ASEL, Instrument Student
Sacramento, CA

[Matt Barrow]

"Cub Driver" > wrote in message
...
> On Mon, 20 Jun 2005 12:40:40 -0700, Mark Hansen >
> wrote:
>
> >These represent the congested parts of the cities. This should
> >(roughly) match the look of the city when lit up at night.
>
> Amazing. Nobody ever told me that!

You've had a deprived life. :~(

>
> What would we do with newsgroups to consume our time and fill our
> minds with facts?

How would you handle this:

ATC tells me "Stay west of Federal Blvd during your departure".

I response "I can't make out the street signs from up here".

[Mark Hansen]

On 6/21/2005 13:59, Matt Barrow wrote:

> "Cub Driver" > wrote in message
> ...
>> On Mon, 20 Jun 2005 12:40:40 -0700, Mark Hansen >
>> wrote:
>>
>> >These represent the congested parts of the cities. This should
>> >(roughly) match the look of the city when lit up at night.
>>
>> Amazing. Nobody ever told me that!
>
> You've had a deprived life. :~(
>
>>
>> What would we do with newsgroups to consume our time and fill our
>> minds with facts?
>
> How would you handle this:
>
> ATC tells me "Stay west of Federal Blvd during your departure".
>
> I response "I can't make out the street signs from up here".

Was this a rhetorical question? If ATC references the landmark, it
should be a navigation landmark, and indicated on the sectional
with a magenta flag; right?

The A/FD and Flight Guide are other good places for 'local'
information like this. When they have a documented procedure like
this, they will usually show it on the airport diagram in or both
of those books.

--
Mark Hansen, PP-ASEL, Instrument Student
Sacramento, CA

[Matt Barrow]

"Mark Hansen" > wrote in message
...
> On 6/21/2005 13:59, Matt Barrow wrote:
>
> >
> > How would you handle this:
> >
> > ATC tells me "Stay west of Federal Blvd during your departure".
> >
> > I response "I can't make out the street signs from up here".
>
> Was this a rhetorical question?

Not entirely.

> If ATC references the landmark, it
> should be a navigation landmark, and indicated on the sectional
> with a magenta flag; right?

Yes.

> The A/FD and Flight Guide are other good places for 'local'
> information like this. When they have a documented procedure like
> this, they will usually show it on the airport diagram in or both
> of those books.

In the case in point (several years ago), I did know the location but I
don't recall if it was on the chart and it most definitely was NOT on the
procedure chart. I wonder how many such Nav fixes are discernable to
non-locals?


--
Matt
---------------------
Matthew W. Barrow
Site-Fill Homes, LLC.
Montrose, CO

[Jimbob]

My flight instructor. I haven't verified it, but it made sense.



On Tue, 21 Jun 2005 03:08:45 GMT, "Steven P. McNicoll"
> wrote:

>
>"Jimbob" > wrote in message
...
>>
>> IIRC, The yellow represents areas under the FAR's which are
>> considered congested areas and require 1000' clearance within a 2000'
>> radius.
>>
>
>From what do you recall that?
>

Jim

http://www.unconventional-wisdom.org

[Steven P. McNicoll]

"Jimbob" > wrote in message
...
>
> My flight instructor. I haven't verified it, but it made sense.
>

I think your instructor was blowing smoke.

[Jimbob]

Hmm. Then the question arises, what feature of a VFR sectional shows
the boundaries of congested areas? If it isn't documented, I don't
see how legally they can enforce it.

Other than the obvious "We're the FAA, that's how"


On Tue, 21 Jun 2005 03:42:06 GMT, "Dave Stadt" >
wrote:

>\
>"Jimbob" > wrote in message
...
>> IIRC, The yellow represents areas under the FAR's which are
>> considered congested areas and require 1000' clearance within a 2000'
>> radius.
>
>Well no. Don't think you can find any legal reference to support your
>claim. If you compare the yellow on a sectional and a terminal area chart
>they don't match.
>

Jim

http://www.unconventional-wisdom.org

[George Patterson]

Jimbob wrote:
> Hmm. Then the question arises, what feature of a VFR sectional shows
> the boundaries of congested areas? If it isn't documented, I don't
> see how legally they can enforce it.
>
> Other than the obvious "We're the FAA, that's how"

That's basically it. The no-so-funny joke goes that, if someone can get your
N-number without binocs and registers a complaint, you were too low.

George Patterson
Why do men's hearts beat faster, knees get weak, throats become dry,
and they think irrationally when a woman wears leather clothing?
Because she smells like a new truck.