Sectional Chart Question

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

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???

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 he

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

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???

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 he

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

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

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.

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

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.

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