Questions on VFR sectionals and TACs

"Ron Natalie" wrote in message
m...

The nominal diameter is 4.3 NM (5 SM). There
may be extensions either as class D or class E surface area that
accomodate the instrumetn approaches. They're centered on the
airport reference point.


There is no nominal diameter for Class D or E surface areas. The standard
is 3.5 NM plus the distance from the Airport Reference Point to the end of
the outermost runway.

Christopher Brian Colohan writes:

North of Boston you will find a large white-ground circle outlined by
a thick cyan dashed line.

Looks like the one around Washington. I think it means that one of
the President's friends lives somewhere near there, so all aircraft
for dozens of miles around are prohibited so as not to disturb the
royals.

--
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Christopher Brian Colohan writes:

I've assumed that the reason for doing this is to identify areas in
which you can expect to find IFR planes. I would guess that you don't
want to have IFR planes going through areas too low or far away from
antennas to have radio communications with ATC. (Could someone
correct me if my guess is wrong?)

Isn't IFR allowed in both Class E and Class G?

--
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Dashed cyan is actually class E surface area.

Not cyan. Rather, class E is depicted by that horrible purply color the
FAA erroniously calls "magenta". What they print on the chart is not
magenta by any stretch of the imagination. Magenta is beautiful; you
can see magenta in the deluxe Crayola crayon box. The FAA color should
be called "FAA feh".

Cyan is more like a deep blue. Real cyan is also beautiful.

Jose
--
"Never trust anything that can think for itself, if you can't see where
it keeps its brain." (chapter 10 of book 3 - Harry Potter).
for Email, make the obvious change in the address.

Bob Noel writes:

In article ,
Christopher Brian Colohan wrote:

North of Boston you will find a large white-ground circle outlined by
a thick cyan dashed line.

Not anymore (look at the 74th edition of the NY sectional)

Heh. Don't have that one yet. :-)

The meaning of white ground or a thick cyan dashed line is not defined
in the chart legend, nor is it defined in the book you point at. Any
guess what this is? (And why the FAA thinks it is worth putting on
the chart, but not worth documenting what it means?)

On the 73rd edition of the NY sectional there is indeed a note
that P-67 is expanded by special notam.

I found the note, but only figured out what it was associated with
_after_ someone explained the dashed circle to me. I guess I find it
puzzling that there are symbols used on the map which don't appear in
any legend... (Especially when just adding them to the legend with a
description like "heavy cyan dashed line == TFR outline" would clear
everything up.)

Chris

Mxsmanic,

It's just hard to figure out whether I'm inside or outside the
boundaries without a radius and center point.


You're going at this the wrong way. In flight, what you do is simply
look at the chart, find some ground features close to the border line
of the airspace, look out the window, find the same ground features -
and presto, you know where you are in relation to the airspace. For IFR
flight, airspace doesn't matter much, since the controller will do
everything necessary for you.

Also, many circular airspaces are centered around a VOR-DME, so there's
another help. Figuring the radius (which is normally standardized for
certain types of airspace) is pretty easy, since the scale of a
sectional is the same every time and you have a ruler.

The logic for class E lower limits is in IFR traffic being in it. Class
E means higher visibility requirements for VFR, so they can separate
themselves from IFR traffic. You may recall the thread in which we
tried VERY HARD to make you understand that concept. If you still
haven't grasped it, it's no surprise you don't understand the logic of
Class E lower limits. What comes round...

--
Thomas Borchert (EDDH)

Mxsmanic,

Isn't IFR allowed in both Class E and Class G?


Yes, but along an airway or and approach, IFR traffic is much more
likely.

--
Thomas Borchert (EDDH)

In article ,
Christopher Brian Colohan wrote:

North of Boston you will find a large white-ground circle outlined by
a thick cyan dashed line.

Not anymore (look at the 74th edition of the NY sectional)

Heh. Don't have that one yet. :-)

I literally got it from the club a few hours earlier as he unpacked
the boxes. :-)

--
Bob Noel
Looking for a sig the
lawyers will hate

Christopher Brian Colohan wrote:


The meaning of white ground or a thick cyan dashed line is not defined
in the chart legend, nor is it defined in the book you point at. Any
guess what this is? (And why the FAA thinks it is worth putting on
the chart, but not worth documenting what it means?)

Correct. NACO finally adopted that to mean special flight restricted
airspace. The other big use fo it is the FRZ in Washington and P-40
(Camp David) in DC.

Are we talking about the one over Bush the First's place in
Kennebunkport?

I've assumed that the reason for doing this is to identify areas in
which you can expect to find IFR planes. I would guess that you don't
want to have IFR planes going through areas too low or far away from
antennas to have radio communications with ATC. (Could someone
correct me if my guess is wrong?)

Not where you can expect to find IFR planes, but where you can
expect NOT to find VFR planes if the weather is below minimums.