Vertical Card Compasses vs GPS Compass Display

How well do the vertical card compasses work and hold up in real world
conditions ( constantly circling, sticking etc) ?

Some of the GPS's have a compass display. Is that a viable alternative
to a vertical card compass (still having regular old style compass as
backup) ?

I would welcome replies from those with experience with either or
both.

Stan

wrote:

How well do the vertical card compasses work and hold up in real world
conditions ( constantly circling, sticking etc) ?

Some of the GPS's have a compass display. Is that a viable alternative
to a vertical card compass (still having regular old style compass as
backup) ?

I would welcome replies from those with experience with either or
both.

Stan

Unless the GPS has a magnetic compass sensor, its compass display
gives you direction in which you are moving on the ground, not your
heading. This may or may not be desirable depending on what you want
to do with the information. If you want to get to destination based on
magnetic direction it is fine. If you want to compute winds it is
totally wrong. Converse is true if GPS has magnetic sensor and gives
you it's information. The only problem there is that so far I have not
seen one like that that I would trust.

Cheers,
Henryk Birecki

My vertical card compass is terrible, it sticks alot, then spins out.
And it is mounted up on top of my glare hood obstructing vision.

I frankly don't see the need for a compass much in a glider. I keep
orientated using landmarks like mountains (ridges are great),
rivers,lakes highways etc.

The gps is also good for direction in straight flight, but I just use
a digital display, not a compass card display.

Todd Smith
3S

"toad" wrote in message
oups.com...
My vertical card compass is terrible, it sticks alot, then spins out.
And it is mounted up on top of my glare hood obstructing vision.


This can be fixed. The rotating card is made of cardboard which warps and
rubs on the instrument glass. I removed the glass and straightened the
cardboard so the compass spins easily.

I frankly don't see the need for a compass much in a glider. I keep
orientated using landmarks like mountains (ridges are great),
rivers,lakes highways etc.

The gps is also good for direction in straight flight, but I just use
a digital display, not a compass card display.

Todd Smith
3S


Me too. Thats why my vertical card compass is on a shelf and not in the
glider.

BD

wrote:

Some of the GPS's have a compass display. Is that a viable alternative
to a vertical card compass (still having regular old style compass as
backup) ?

That works for me. I have a Garmin GPS II+ and the bearing page is my
preferred directional display when I'm flying. My compass is tucked away
at the bottom of the panel for emergency use only.

As it sounds like you haven't seen a GPS II+, here's a description. The
bearing page shows a circular disk containing a large arrow that points
at the selected waypoint. Round it is a ring showing the main compass
points. Like a compass card, the ring rotates so heading is always at
the top of the display. For good measure the heading and waypoint
bearing are also shown as three digit numbers.

Some other basic handheld Garmins (12XL, GPS III+, eTrex, GPSMAP 60 and
76) also have this display page.

You may still be able to find the older models (GPS II+, III+, 12XL) on
eBay. Of the current basic handhelds, the GPSMAP series look the best
suited for our use because all controls are on the front next to the
display. The Geko series are too small to be practical while the eTrex
series have their controls on the edges which probably makes a panel
mounted one harder to use.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

On Sep 20, 8:09 pm, Bill Zaleski wrote:
On Fri, 21 Sep 2007 00:01:32 +0100, Martin Gregorie





wrote:
wrote:

Some of the GPS's have a compass display. Is that a viable alternative
to a vertical card compass (still having regular old style compass as
backup) ?

That works for me. I have a Garmin GPS II+ and the bearing page is my
preferred directional display when I'm flying. My compass is tucked away
at the bottom of the panel for emergency use only.

As it sounds like you haven't seen a GPS II+, here's a description. The
bearing page shows a circular disk containing a large arrow that points
at the selected waypoint. Round it is a ring showing the main compass
points. Like a compass card, the ring rotates so heading is always at
the top of the display. For good measure the heading and waypoint
bearing are also shown as three digit numbers.

Some other basic handheld Garmins (12XL, GPS III+, eTrex, GPSMAP 60 and
76) also have this display page.

You may still be able to find the older models (GPS II+, III+, 12XL) on
eBay. Of the current basic handhelds, the GPSMAP series look the best
suited for our use because all controls are on the front next to the
display. The Geko series are too small to be practical while the eTrex
series have their controls on the edges which probably makes a panel
mounted one harder to use.

A GPS can not, and will not display heading. No GPS can do this. The
most it can do is display track, which is also heading only if there
is no wind correction. It can not be substituted for a compass.- Hide quoted text -

- Show quoted text -

I love my vertical card compass. It is a PAI-700. I have it mounted
on the bottom of the pedestal where I occasionally look at it. No
problems with sticking. I use it to verify rough heading before my
GPS has a chance to register my track. In some parts of the country
the landscape is monotonous without distinguishing landmarks such as
mountains or ridges. I also believe that a compass is required
equipment for any aircraft - GPS is not a substitute.

Tom Nau

"Tom N." wrote in message
ps.com...
On Sep 20, 8:09 pm, Bill Zaleski wrote:
On Fri, 21 Sep 2007 00:01:32 +0100, Martin Gregorie





wrote:
wrote:

Some of the GPS's have a compass display. Is that a viable alternative
to a vertical card compass (still having regular old style compass as
backup) ?

That works for me. I have a Garmin GPS II+ and the bearing page is my
preferred directional display when I'm flying. My compass is tucked away
at the bottom of the panel for emergency use only.

As it sounds like you haven't seen a GPS II+, here's a description. The
bearing page shows a circular disk containing a large arrow that points
at the selected waypoint. Round it is a ring showing the main compass
points. Like a compass card, the ring rotates so heading is always at
the top of the display. For good measure the heading and waypoint
bearing are also shown as three digit numbers.

Some other basic handheld Garmins (12XL, GPS III+, eTrex, GPSMAP 60 and
76) also have this display page.

You may still be able to find the older models (GPS II+, III+, 12XL) on
eBay. Of the current basic handhelds, the GPSMAP series look the best
suited for our use because all controls are on the front next to the
display. The Geko series are too small to be practical while the eTrex
series have their controls on the edges which probably makes a panel
mounted one harder to use.

A GPS can not, and will not display heading. No GPS can do this. The
most it can do is display track, which is also heading only if there
is no wind correction. It can not be substituted for a compass.- Hide
quoted text -

- Show quoted text -

I love my vertical card compass. It is a PAI-700. I have it mounted
on the bottom of the pedestal where I occasionally look at it. No
problems with sticking. I use it to verify rough heading before my
GPS has a chance to register my track. In some parts of the country
the landscape is monotonous without distinguishing landmarks such as
mountains or ridges. I also believe that a compass is required
equipment for any aircraft - GPS is not a substitute.

Tom Nau


We need an FAR reference.

Does the FAR say that ALL aircraft MUST have a compass? Or does it say that
the aircraft in question must be equipped as shown in the Minimum Equipment
List found in the certification documents and reflected in the POH? I think
it's the later where if the POH doesn't list a compass as required
equipment, you can fly without one. Of course, MOST aircraft POH's do list
a compass - but not all.

Yes it's true that ordinary GPS receivers do not generate and display
compass heading - but some do. These are dual-antenna, carrier-phase
receivers that generate compass heading data referenced to TRUE NORTH. This
heading data is in NMEA format that some glide computers can use to generate
extremely accurate real-time vector wind.

Whether a particular receiver does or does not display compass data, ground
track is far more useful anyway. I care about the direction I'm going much
more than the direction I'm pointing. A long time ago I was given a vector
of 270 degrees magnetic when there was a 50 knot north wind. The resulting
ground track was WSW. The controller grumbled at me until I turned NW to
achieve a ground track of 270. The ATC controllers were much happier with
me when I flew ground track vectors.

Bill Daniels

On Sep 20, 7:37 pm, "Bill Daniels" bildan@comcast-dot-net wrote:
"Tom N." wrote in message

ps.com...





On Sep 20, 8:09 pm, Bill Zaleski wrote:
On Fri, 21 Sep 2007 00:01:32 +0100, Martin Gregorie

wrote:
wrote:

Some of the GPS's have a compass display. Is that a viable alternative
to a vertical card compass (still having regular old style compass as
backup) ?

That works for me. I have a Garmin GPS II+ and the bearing page is my
preferred directional display when I'm flying. My compass is tucked away
at the bottom of the panel for emergency use only.

As it sounds like you haven't seen a GPS II+, here's a description. The
bearing page shows a circular disk containing a large arrow that points
at the selected waypoint. Round it is a ring showing the main compass
points. Like a compass card, the ring rotates so heading is always at
the top of the display. For good measure the heading and waypoint
bearing are also shown as three digit numbers.

Some other basic handheld Garmins (12XL, GPS III+, eTrex, GPSMAP 60 and
76) also have this display page.

You may still be able to find the older models (GPS II+, III+, 12XL) on
eBay. Of the current basic handhelds, the GPSMAP series look the best
suited for our use because all controls are on the front next to the
display. The Geko series are too small to be practical while the eTrex
series have their controls on the edges which probably makes a panel
mounted one harder to use.

A GPS can not, and will not display heading. No GPS can do this. The
most it can do is display track, which is also heading only if there
is no wind correction. It can not be substituted for a compass.- Hide
quoted text -

- Show quoted text -

I love my vertical card compass. It is a PAI-700. I have it mounted
on the bottom of the pedestal where I occasionally look at it. No
problems with sticking. I use it to verify rough heading before my
GPS has a chance to register my track. In some parts of the country
the landscape is monotonous without distinguishing landmarks such as
mountains or ridges. I also believe that a compass is required
equipment for any aircraft - GPS is not a substitute.

Tom Nau

We need an FAR reference.

Does the FAR say that ALL aircraft MUST have a compass? Or does it say that
the aircraft in question must be equipped as shown in the Minimum Equipment
List found in the certification documents and reflected in the POH? I think
it's the later where if the POH doesn't list a compass as required
equipment, you can fly without one. Of course, MOST aircraft POH's do list
a compass - but not all.

Yes it's true that ordinary GPS receivers do not generate and display
compass heading - but some do. These are dual-antenna, carrier-phase
receivers that generate compass heading data referenced to TRUE NORTH. This
heading data is in NMEA format that some glide computers can use to generate
extremely accurate real-time vector wind.

Whether a particular receiver does or does not display compass data, ground
track is far more useful anyway. I care about the direction I'm going much
more than the direction I'm pointing. A long time ago I was given a vector
of 270 degrees magnetic when there was a 50 knot north wind. The resulting
ground track was WSW. The controller grumbled at me until I turned NW to
achieve a ground track of 270. The ATC controllers were much happier with
me when I flew ground track vectors.

Bill Daniels- Hide quoted text -

- Show quoted text -

I have to agree. Perhaps it's just my ignorance, but when is the
direction that the nose is pointing useful information? My compass
works fine, and is a great source of amusement, but gives me little
useful information, other than helping guesstimate winds by comparing
it to my track.
Jim

Bill Daniels wrote:

We need an FAR reference.

No idea about FAR, but in JAR country, a magnetic compass is required
for motorgliders (self sustainers count, too). No magnetic compass is
required for gliders without a fuel to noise converter.

wrote:

I have to agree. Perhaps it's just my ignorance, but when is the
direction that the nose is pointing useful information?

In motorized IFR flights, ATC may ask for your heading and speed. Based
on that information and their radar plot, they can calculate the wind at
your altitude. This is useful information to them plus they then can
vector you by giving you headings.

Not much useful information in a glider, though, as long as your glide
computer works. If however you suffer a power failure in unknown country
with no distinct landmarks and/or poor visibility, I can tell you that
you will be glad to have that gadget. Dont' ask me why I know.