CNS-80 VNAV

On Tue, 26 Oct 2004 03:37:16 GMT, "John R. Copeland"
wrote:

Now, though, non-precision LNAV approaches with defined vertical paths will
display vertical guidance only on the new NAV display page of the CNX-80,
but the external VDI instrument will not display that same vertical guidance.
In LNAV, my glideslope flag is retracted, but the glideslope pointer is driven
beyond the end of the scale, hiding it from view throughout the approach.

That's unfortunate. But I would think it would be more logical to also
flag the glideslope.


In the remaining case of LNAV approaches without defined vertical path,
the VDI portion of the CNX-80's NAV page is entirely absent.

That makes sense.


As I mentioned in a follow-up post, later than the one you replied to,
the intentional suppression of drive to external VDIs effectively prevents
a 3-axis autopilot from locking onto the vertical guidance information
during a non-precision approach. The pilot must manage the descent.

I do not know whether that choice was at Garmin's volition,
or whether it was an FAA requirement.

I suspect the latter.


--ron

"Ron Rosenfeld" wrote in message =
...
On Tue, 26 Oct 2004 03:37:16 GMT, "John R. Copeland"
wrote:
=20
Now, though, non-precision LNAV approaches with defined vertical paths =
will
display vertical guidance only on the new NAV display page of the =
CNX-80,
but the external VDI instrument will not display that same vertical =
guidance.
In LNAV, my glideslope flag is retracted, but the glideslope pointer =
is driven
beyond the end of the scale, hiding it from view throughout the =
approach.
=20
That's unfortunate. But I would think it would be more logical to =
also
flag the glideslope.
=20
--ron

I was about to speculate that the glideslope flag might get retracted by =
the
flight director, because it receives a strong signal to overdrive the =
VDI pointer.
But then I checked the CNX-80 Installation Manual, and I found that
the I/O Expansion Connector P5, pins 52 and 55, are the Aux VDI +Valid,
and the Aux VDI -Valid (the current-return path), respectively.
So the CNX-80 is designed to control the external VDI flag,
and I'm assuming that my flight director is wired accordingly.

I, too, was surprised by the retracted flag with denied aux-VDI =
guidance.
But it's no big deal. I could see it as a reminder to watch the NAV =
page.
Things like these are why we don't learn our equipment from books alone.
We must fly to really learn.
---JRC---

"John R. Copeland" wrote in message
...
I was about to speculate that the glideslope flag might get retracted by
the
flight director, because it receives a strong signal to overdrive the VDI
pointer.
But then I checked the CNX-80 Installation Manual, and I found that
the I/O Expansion Connector P5, pins 52 and 55, are the Aux VDI +Valid,
and the Aux VDI -Valid (the current-return path), respectively.
So the CNX-80 is designed to control the external VDI flag,
and I'm assuming that my flight director is wired accordingly.

Ya' know, Dave Barry says the first inclination of a "Real Guy" is that when
he gets a new gadget, he wants to take it apart.


Matt
---------------------
Matthew W. Barrow
Site-Fill Homes, LLC.
Montrose, CO

"Matt Barrow" wrote in message =
...
=20
=20
Ya' know, Dave Barry says the first inclination of a "Real Guy" is =
that when
he gets a new gadget, he wants to take it apart.
=20
Matt

That would be me, alright!
What're we gonna do without Dave Barry after the first of the year?
---JRC---

In article , "John R.
Copeland" wrote:

What're we gonna do without Dave Barry after the first of the year?

????

--
Bob Noel
Seen on Kerry's campaign airplane: "the real deal"
oh yeah baby.

"Bob Noel" wrote in message =
...
In article , "John R.=20
Copeland" wrote:
=20
What're we gonna do without Dave Barry after the first of the year?
=20
????
=20

Exactly! I don't know, either. :-(

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


Ya' know, Dave Barry says the first inclination of a "Real Guy" is that
when
he gets a new gadget, he wants to take it apart.

Matt

That would be me, alright!
What're we gonna do without Dave Barry after the first of the year?

He's not giving up writing books, is he?, or just his column?

"Matt Barrow" wrote in message =
...
=20
"John R. Copeland" wrote in message
...
"Matt Barrow" wrote in message
...


Ya' know, Dave Barry says the first inclination of a "Real Guy" is =
that
when
he gets a new gadget, he wants to take it apart.

Matt

That would be me, alright!
What're we gonna do without Dave Barry after the first of the year?
=20
He's not giving up writing books, is he?, or just his column?


Dunno about books, but he's stopping his column for at least a year.
That's a bad sign. Columnists rarely are the same after a year's =
layoff.