En route glide slope?

I was staring at the VOR-head during a flight a while back, and started
wondering why we only use half of it most of the time. Whether by GPS or
VOR, the CDI provides us with lateral navigation. But the glide slope
needle sits unused until the very end of the flight (if then {8^).

Why?

Using older technology, why not have an altitude bug and let the bug and
altimeter feed the GS needle, providing VNAV information en route?

Will WAAS-ified GPSs be able to drive the GS needle en route?

Curiously...

Andrew

On Fri, 19 Nov 2004 15:08:56 -0500, Andrew Gideon
wrote:

I was staring at the VOR-head during a flight a while back, and started
wondering why we only use half of it most of the time. Whether by GPS or
VOR, the CDI provides us with lateral navigation. But the glide slope
needle sits unused until the very end of the flight (if then {8^).

Why?

Using older technology, why not have an altitude bug and let the bug and
altimeter feed the GS needle, providing VNAV information en route?

Will WAAS-ified GPSs be able to drive the GS needle en route?

Not trying to be argumentative, but a simple look at the altimeter
provides all the info you need to know. I do not see much value add
by having a GS needle tell me I am 100 feet too high (enroute), when I
can look at the altimeter and get the same info.

Another issue: The setting of the enroute cruise altitude introduces
an opportunity for error - where the pilot sets the wrong cruise
altitude.

Of course, this issue already exists with the more advanced altitude
preset autopilots. I wonder if setting the wrong altitude is a
problem with those?

-Nathan

Nathan Young wrote:

Will WAAS-ified GPSs be able to drive the GS needle en route?

Not trying to be argumentative, but a simple look at the altimeter
provides all the info you need to know.

Even more to the point, a look at the altimeter provides you with the
correct information, namely pressure altitude.

Stefan

"Stefan" wrote in message
...
Nathan Young wrote:

Will WAAS-ified GPSs be able to drive the GS needle en route?

Not trying to be argumentative, but a simple look at the altimeter
provides all the info you need to know.

Even more to the point, a look at the altimeter provides you with the
correct information, namely pressure altitude.


Uh... Stefan..., a look at the altimeter provides you with *indicated*
altitude. It only shows *pressure* altitude if the altimeter setting is set
to 29.92

Icebound wrote:
"Stefan" wrote in message
...

Nathan Young wrote:


Will WAAS-ified GPSs be able to drive the GS needle en route?

Not trying to be argumentative, but a simple look at the altimeter
provides all the info you need to know.

Even more to the point, a look at the altimeter provides you with the
correct information, namely pressure altitude.



Uh... Stefan..., a look at the altimeter provides you with *indicated*
altitude. It only shows *pressure* altitude if the altimeter setting is set
to 29.92


Sounds like his enroute flight takes place above FL 180

Dave

Dave S wrote
Sounds like his enroute flight takes place above FL 180

Sounds as if you have never flown outside of the USofA.
Notice that he WAS posting from "ch".

Bob Moore

"Icebound" wrote in message
...

"Stefan" wrote in message
...
Nathan Young wrote:

Will WAAS-ified GPSs be able to drive the GS needle en route?

Not trying to be argumentative, but a simple look at the altimeter
provides all the info you need to know.

Even more to the point, a look at the altimeter provides you with the
correct information, namely pressure altitude.


Uh... Stefan..., a look at the altimeter provides you with *indicated*
altitude. It only shows *pressure* altitude if the altimeter setting is
set to 29.92

All altitudes shown on an altimeter are "pressure altitudes" (as opposed to
true altitudes) since the altimeter is an air pressure guage marked in feet.

Mike
MU-2

Icebound wrote:

Uh... Stefan..., a look at the altimeter provides you with *indicated*
altitude. It only shows *pressure* altitude if the altimeter setting is set
to 29.92

Uh... Icebound..., the altimeter *always* indicates pressure altitude.
To get useful information, you must set the altimeter appropriately, of
course. Appropriately may or may not mean 1013.

On the other hand, your GPS always gives you GPS altitude, which is of
no value in flight.

Stefan

"Stefan" wrote in message
...

Uh... Icebound..., the altimeter *always* indicates pressure altitude.
To get useful information, you must set the altimeter appropriately, of
course. Appropriately may or may not mean 1013.

You two are just arguing about terminology. I've always thought the norm is
to refer to an altitude measured on an altimeter (rather than another
instrument like a GPS) as "barometric altitude", with "pressure altitude"
reserved for the indicated altitude with 1013/29.92 set.

Julian Scarfe
..

Andrew,
The software on my Pocket PC provides you with a highway in the sky if
you feed it the altitude you want for each leg.
Michelle

Andrew Gideon wrote:

I was staring at the VOR-head during a flight a while back, and started
wondering why we only use half of it most of the time. Whether by GPS or
VOR, the CDI provides us with lateral navigation. But the glide slope
needle sits unused until the very end of the flight (if then {8^).

Why?

Using older technology, why not have an altitude bug and let the bug and
altimeter feed the GS needle, providing VNAV information en route?

Will WAAS-ified GPSs be able to drive the GS needle en route?

Curiously...

Andrew




--

Michelle P ATP-ASEL, CP-AMEL, and AMT-A&P

"Elisabeth" a Maule M-7-235B (no two are alike)

Volunteer Pilot, Angel Flight Mid-Atlantic

Volunteer Builder, Habitat for Humanity