ATC Altimeter Settings

John R. Copeland wrote:



Chip, you didn't mention enroute altimeter settings being different from surface ones.
I've seen that condition in the Rocky Mountains, but I can't specifically recall
if I've ever seen it in the central and eastern U.S.

Controllers issue altimeter settings from ground stations. Where else
would they come from?

In article ,
Newps wrote:

John R. Copeland wrote:



Chip, you didn't mention enroute altimeter settings being different from
surface ones.
I've seen that condition in the Rocky Mountains, but I can't specifically
recall
if I've ever seen it in the central and eastern U.S.

Controllers issue altimeter settings from ground stations. Where else
would they come from?

You get them off DUATS like the rest of us?

Roy Smith wrote:
In article ,
Newps wrote:


John R. Copeland wrote:


Chip, you didn't mention enroute altimeter settings being different from
surface ones.
I've seen that condition in the Rocky Mountains, but I can't specifically
recall
if I've ever seen it in the central and eastern U.S.

Controllers issue altimeter settings from ground stations. Where else
would they come from?


You get them off DUATS like the rest of us?

Yes, and they come from ground stations. There are no special enroute
airborne stations in the mountains.

I fail to see what the usefulness would be.

As long as everyone is flying with the same lapse rate error, who
cares?




On Mon, 04 Apr 2005 08:12:04 -0600, Newps wrote:



Roy Smith wrote:
In article ,
Newps wrote:


John R. Copeland wrote:


Chip, you didn't mention enroute altimeter settings being different from
surface ones.
I've seen that condition in the Rocky Mountains, but I can't specifically
recall
if I've ever seen it in the central and eastern U.S.

Controllers issue altimeter settings from ground stations. Where else
would they come from?


You get them off DUATS like the rest of us?

Yes, and they come from ground stations. There are no special enroute
airborne stations in the mountains.

"Newps" wrote in message =
...
=20
=20
Roy Smith wrote:
In article ,
Newps wrote:
=20
=20
John R. Copeland wrote:


Chip, you didn't mention enroute altimeter settings being different =
from=20
surface ones.
I've seen that condition in the Rocky Mountains, but I can't =
specifically=20
recall
if I've ever seen it in the central and eastern U.S.

Controllers issue altimeter settings from ground stations. Where =
else=20
would they come from?
=20
=20
You get them off DUATS like the rest of us?
=20
Yes, and they come from ground stations. There are no special enroute =

airborne stations in the mountains.

In the Rockies, there are ground stations at widely varying elevations.
I've guessed that ATC might not use settings from airports in deep =
valleys
for enroute settings, wherever more representative values are available.
The terminology I've heard used at specific locations is something like:
"XXX altimeter nn.nn, Area altimeter nn.mm."
I don't really know how the "Area" numbers are established,
but I'd certainly want to use the local airport setting for landings.

"John R. Copeland" wrote in message
...

In the Rockies, there are ground stations at widely varying elevations.
I've guessed that ATC might not use settings from airports in deep valleys
for enroute settings, wherever more representative values are available.
The terminology I've heard used at specific locations is something like:
"XXX altimeter nn.nn, Area altimeter nn.mm."
I don't really know how the "Area" numbers are established,
but I'd certainly want to use the local airport setting for landings.


Where did you hear "area altimeter nn.nn"?

"John R. Copeland" wrote in message
...

In the Rockies, there are ground stations at widely varying elevations.
I've guessed that ATC might not use settings from airports in deep valleys
for enroute settings, wherever more representative values are available.

How would a station be more representative if it was/wasn't in a valley or
on a hill top?

"Steven P. McNicoll" wrote in message =
. net...
=20
"John R. Copeland" wrote in message=20
...

In the Rockies, there are ground stations at widely varying =
elevations.
I've guessed that ATC might not use settings from airports in deep =
valleys
for enroute settings, wherever more representative values are =
available.
The terminology I've heard used at specific locations is something =
like:
"XXX altimeter nn.nn, Area altimeter nn.mm."
I don't really know how the "Area" numbers are established,
but I'd certainly want to use the local airport setting for landings.

=20
Where did you hear "area altimeter nn.nn"?


One place I recall specifically was KBCE.

"Matt Barrow" wrote in message =
...
=20
"John R. Copeland" wrote in message
...
=20
In the Rockies, there are ground stations at widely varying =
elevations.
I've guessed that ATC might not use settings from airports in deep =
valleys
for enroute settings, wherever more representative values are =
available.
=20
How would a station be more representative if it was/wasn't in a =
valley or
on a hill top?
=20


In the case of non-standard lapse rates, the lower the airport,
the more the altimeter differs from true height across mountain peaks.

John R. Copeland wrote:

In the case of non-standard lapse rates, the lower the airport,
the more the altimeter differs from true height across mountain peaks.

Lapse rate is temp and has little effect on the altimeter setting.
Because you are already separated from the ground by 2000 feet it is
much more important that everybody have the same setting. No such thing
as an area altimeter setting.