Funny Story on the old Air Port Traffic Area

[BT]

"Danny Deger" > wrote in message
...

> My understanding now is there is no longer this subtle distintion between
> Class D and Class E going to the ground. The area around a controlled
> airport is Class D and is marked with a dashed blue line around the
> airport. No more chance of class D airspace that is "marked" only because
> the airport is blue.
>
> Danny Deger

It may not always be marked, when our local airport first went to "contract
tower" from "no tower", it was CLASS D, and it was painted blue on the
charts, but the CLASS D dashed blue line was not printed on the charts with
no altitude markings. It took two chart revisions to catch up.

The only way to tell was NOTAMS. The question to ask the new "long waiting
time" Lockheed FSS is... if I am filed into a different but nearby airport,
are you going to give me the airspace NOTAM for the new class D at the
airport I am not flying into?

BT

[Ron Natalie]

BT wrote:

>
> It may not always be marked, when our local airport first went to "contract
> tower" from "no tower", it was CLASS D, and it was painted blue on the
> charts, but the CLASS D dashed blue line was not printed on the charts with
> no altitude markings. It took two chart revisions to catch up.
>

Yep, it takes a long time to catch u.

Danny was right. In the old days there were Airport Traffic Areas
which was defined as 5 statute miles from a control tower up to 3000' AGL.
They were not in themselves controlled airspace. They however
were usually colocated with Control Zones. The control zone might
or might not have been 5 miles in diameter. You might also find
control zones inside class B or C airspace. The control zone had
a few additional restrictions on VFR traffic.

When they rewrote the alphabet airspace, they did away with the
goofy unmarked ATA (so they claimed) and added the class D
surface area space to suck up both the CZ and ATA concepts.
The class D is 4.6 NM (which you'll find is about the same
as 5 SM) and they made provision for class E extensions to
the class D (to handle the little notches of CZ that used
to protrude past the ATA boundaries).

Of course, it only took them about a year to realize that there
were times they wanted to have a control tower but didn't want
to set up a class D airspace (controlled airspace takes a NPRM
process to set up). Temporary or new towers frequently get
turned on without the class D having been established. So,
they brought back the ATA except that they don't call it that.
You'll find a quaint additional reg that says you gotta call
the tower while within 4NM and 2500 of an control tower (even
in class E or G airspace... 91.127(c), 91.126(d)).

One problem with the alphabet airspace reclass is we did lose
some nice terms. "Control Zone" was much better than "Surface
Area of controlled airspace designated for an airport". And
Airport Traffic Area is better than "within 4NM miles from the
surface to 2500' agl of an airport with an operating control tower."

[Danny Deger]

Back before we called it class D, we called the area around a controlled
airport an Airport Traffic Area. It extended for 5 NM (SM?) and up to 3,000
AGL from the tower. Just to confuse matters, 99.9% of controlled air ports
had a region around them that controlled airspace went to the ground. It
was always close to the boundary of the ATA, but not the same.

One day I was flying into OK City at night VFR. As I approached the city
from the south I called approach. He imediately tells me to call such and
such tower because I am smack in the middle of his airspace. I look at my
map and see something I had never seen before. A blue airport without the
blue dash lines around it indicating the drop in altitude of controlled
airspace. I had flown this route many times and never seen this fact
before. I talked to the tower, then back to approach control. Approach
asked me to call him on the phone when I got down. I almost didn't. I was
afraid of punitive action. But he was nice and let me know I was not the
first to violate this tower's airspace for the same reason.

My understanding now is there is no longer this subtle distintion between
Class D and Class E going to the ground. The area around a controlled
airport is Class D and is marked with a dashed blue line around the airport.
No more chance of class D airspace that is "marked" only because the airport
is blue.

Danny Deger

[BT]

>>
>
> How does a sectional indicate an airport with a tower but no class D?
>
> Danny Deger

Color of the airport and tower frequency information in the airport data
field next to the colored airport.
It's still BLUE

BT

[Danny Deger]

"Ron Natalie" > wrote in message
m...
snip

> Of course, it only took them about a year to realize that there
> were times they wanted to have a control tower but didn't want
> to set up a class D airspace (controlled airspace takes a NPRM
> process to set up). Temporary or new towers frequently get
> turned on without the class D having been established. So,
> they brought back the ATA except that they don't call it that.
> You'll find a quaint additional reg that says you gotta call
> the tower while within 4NM and 2500 of an control tower (even
> in class E or G airspace... 91.127(c), 91.126(d)).
>

How does a sectional indicate an airport with a tower but no class D?

Danny Deger
> One problem with the alphabet airspace reclass is we did lose
> some nice terms. "Control Zone" was much better than "Surface
> Area of controlled airspace designated for an airport". And
> Airport Traffic Area is better than "within 4NM miles from the
> surface to 2500' agl of an airport with an operating control tower."

[JGalban via AviationKB.com]

Ron Natalie wrote:
>The class D is 4.6 NM (which you'll find is about the same
>as 5 SM) and they made provision for class E extensions to
>the class D (to handle the little notches of CZ that used
>to protrude past the ATA boundaries).
>

As far as I can tell, there's no standard size for a class D circle. They
define the radius when the airspace is established. If you take a look at
a sectional of the airports around Phoenix, you'll see that most are 4NM, but
some are larger and some are smaller. Williams Gateway (IWA) is larger than
average, and on the west side, both Glendale (GEU) and Goodyear (GYR) are
much smaller than average.

John Galban=====>N4BQ (PA28-180)

--
Message posted via http://www.aviationkb.com

[Steven P. McNicoll]

"JGalban via AviationKB.com" <u32749@uwe> wrote in message
news:7230b56508d63@uwe...
>
> As far as I can tell, there's no standard size for a class D circle. They
> define the radius when the airspace is established. If you take a look
> at
> a sectional of the airports around Phoenix, you'll see that most are 4NM,
> but
> some are larger and some are smaller. Williams Gateway (IWA) is larger
> than
> average, and on the west side, both Glendale (GEU) and Goodyear (GYR) are
> much smaller than average.
>

The standard is 3.5 NM plus the distance from the Airport Reference Point to
the end of the outermost runway, rounded up to the next tenth of a mile.
The objective is to maintain departure aircraft within controlled airspace
at a climb fradient of 200' per nautical mile. In cases of rising terrain
the surface area will be a greater.

[Steven P. McNicoll]

"Danny Deger" > wrote in message
...
>
> How does a sectional indicate an airport with a tower but no class D?
>

Here are a couple of examples:

http://map.aeroplanner.com/mapping/chart/chart.cfm?chart=Sectional&typ=APT&txt=ord

http://map.aeroplanner.com/mapping/chart/chart.cfm?chart=Sectional&typ=APT&txt=msn

[Steven P. McNicoll]

"Danny Deger" > wrote in message
...
>
> My understanding now is there is no longer this subtle distintion between
> Class D and Class E going to the ground.
>

There never was. Class D surface areas have always been indicated by a
dashed blue line and Class E surface areas by a dashed magenta line.


>
> The area around a controlled
> airport is Class D and is marked with a dashed blue line around the
> airport.
>

The area around a controlled airport may be Class B, Class C, Class D, Class
E or Class G. If it is Class D it will be designated by a blue dashed line.


>
> No more chance of class D airspace that is "marked" only because
> the airport is blue.
>

There never was.

[Steven P. McNicoll]

"Ron Natalie" > wrote in message
m...
>
> When they rewrote the alphabet airspace, they did away with the
> goofy unmarked ATA (so they claimed) and added the class D
> surface area space to suck up both the CZ and ATA concepts.
> The class D is 4.6 NM (which you'll find is about the same
> as 5 SM) and they made provision for class E extensions to
> the class D (to handle the little notches of CZ that used
> to protrude past the ATA boundaries).
>

There is no standard size for a Class D or Class E surface area. The radius
is 3.5 NM plus the distance from the Airport Reference Point to the end of
the outermost runway, rounded up to the next tenth of a mile. The objective
is to contain departure aircraft within controlled airspace at a climb
gradient of 200' per nautical mile. In cases of rising terrain
the surface area will be larger.

The surface area may also need extensions to contain arrival aircraft. If
all extensions are 2 NM or less they will be Class D airspace. If any
extension is more than 2 NM then all extensions will be Class E.

[Steven P. McNicoll]

"Danny Deger" > wrote in message
...
>
> How does a sectional indicate an airport with a tower but no class D?
>

A blue airport symbol without a blue dashed line.