KLN94 Question

"Bill" wrote in message
ups.com...
On Apr 19, 2:35 pm, "Allen" wrote:
"kevmor" wrote in message

ups.com...

I flew today to try out some more approaches with the KLN94 and the
entire time I was getting "Altitude Fail" in the MSG area, which the
manual says will display "When the altitude input becomes invalid
during operation". If I remember correctly, I think I saw when
turning it on or setting the ALT that it wasn't receiving any altitude
input, so I pushed ALT and set the altimeter to the current setting.
It kept redisplaying though... am I doing something wrong, or is it
getting a bad input possibly?

You do have either an encoding altimeter or blind encoder and it is
hooked
up to the GPS and is functioning properly? You have your transponder
turned
to ALT and not just to on? If the GPS is not hooked up to the encoder
there
should be a way in the setup to tell it there is no encoder connected. I
am
not familiar with the KLN94 but these things are pretty common to all
panel
mount GPS.

The encoder lines are a big party line. They are pulled high by
the transponder usually and the altimeter pulls them low to
signify a "1". The GPS just monitors the lines--or should.
On 90B installations, you are ordered to put some diodes in the
lines so that if the 90B is turned off it won't pull the lines low and
flummox
the transponder-encoder connection.

Might also be that the encoder only gets power if the transponder
is in ALT position; haven't heard of that one. I know that on Narcos,
the encoder only got strobed in mode C--at least on really
old models.

So check your plane: You should be able to turn off the GPS
and still squak the correct altitude; you should be able to turn the
transponder off and still indicate the correct altitude on the GPS.

Bill Hale

I have flown several different aircraft that had GPS that would complain
about no altitude if the transponder wasn't squawking ALT.

Mark Hansen wrote:
On 04/19/07 12:49, kevmor wrote:

I flew today to try out some more approaches with the KLN94 and the
entire time I was getting "Altitude Fail" in the MSG area, which the
manual says will display "When the altitude input becomes invalid
during operation". If I remember correctly, I think I saw when
turning it on or setting the ALT that it wasn't receiving any altitude
input, so I pushed ALT and set the altimeter to the current setting.
It kept redisplaying though... am I doing something wrong, or is it
getting a bad input possibly?



I was told by one of the club CFIs that you need to have your transponder
set to Mode C for this feature to work. So, while on the ground prior
get turning on the transponder (to mode-C), I get the same thing.

Once I've turned on the mode-c, I no longer get the message.

Is it possible the message was originally received while you were on
the ground (before you turned on the mode-c) and you never cleared
the message?


On my KLN 89B I will get that message until the blind encoder is warmed
up and outputting data. It can take up to 6 or 7 minutes.

--

Regards, Ross
C-172F 180HP
KSWI

Peter wrote:

kevmor wrote

I'm learning to use the KLN94 IFR GPS and was wondering about using
the ALT button to set the current altimeter setting. I can see why it
would use this for VNAV, but is it required to set it for normal non-
precision approaches? I think the only thing I've read in the manual
so far was it helps to get the RAIM check done faster or something
like that.

Coming late into this thread...

I have a KLN94, and a KMD550.

*AFAIK* the KLN94 uses the altitude encoder input for only *one*
purpose, and that is RAIM checking if it is receiving less than 4 (or
5?) satellites. Once it is receiving sufficient satellites, the alt
input is ignored.

There is a crude VNAV calculator in the KLN94 which I believe uses the
current GPS altitude, but it could be an exception to that I am
saying.

I have the installation and/or maintenance manuals for the KLN94 -
email me if you would like a copy. It should answer most of the tech
(if not the operating) questions.

Both are available online. Here's the relevant section:

"The KLN 94 functions which use the altitude input are special use
airspace (SUA) alerting, altitude alerting, vertical navigation (VNAV),
and the GPS approach mode. It is a good idea to update the altimeter
baro setting on the ALT 1 page each time you make a change to the
aircraft's altimeter setting."

email: peter at peter2000 dot co dot uk

It's a great GPS for typical enroute GPS usage, plus it displays the
final approach track on conventional approaches, enabling e.g. an NDB
approach to be flown inbound using the GPS / autopilot. I am not sure
how it works for a full US-style GPS approach but we don't have any
over here anyway.

It's also great for full US-style GPS approaches.

--
Don Poitras

Peter wrote:
(Don Poitras) wrote


Both are available online. Here's the relevant section:


Where?


It's also great for full US-style GPS approaches.


I am OK with it for the approach itself, but how does the waypoint
sequencing work after the MAP?

Not sure about the 94, but my 89B will not sequence past the MAP by
design. You have to envoke it. It is ready in the display for you.

--

Regards, Ross
C-172F 180HP
KSWI

Peter wrote:

(Don Poitras) wrote

Both are available online. Here's the relevant section:

Where?

Do a Google for ""kln 94 pilots guide". First hit.
Ditto '"Avionics Library" bendix-king' (without the single quotes). Second
hit, dig down.

I don't verify the accuracy or legality of either of these, but I'm
sure with some digging you could find more.

It's also great for full US-style GPS approaches.

I am OK with it for the approach itself, but how does the waypoint
sequencing work after the MAP?

From the book:

"To perform the published missed approach procedure, press D- to bring
up the direct-to page. The default waypoint will usually be the first
waypoint of the missed approach procedure."

"Confirm this waypoint as the direct to waypoint and press ENTER."

--
Don Poitras

At time of installation, the Maintenance 7 (MNT 7) page should have
been set. Enhanced RS232 data output is selected when a KMD550 is
connected, provided there are no other devices on the same RS232 bus.
The Enhanced RS232 data output includes extra (and as I understand it,
BK-specific and non-standard) output for the display of curved
segments.



On Fri, 04 May 2007 07:48:13 +0100, Peter
wrote:
One Q, since you seem to know this stuff: is there *any* way to get a
KMD550 to display arcs, from the KLN94 database? Mine only ever
displays straight lines, and STARs/SIDs tend to look unrecognisable.

Peter wrote:

(Don Poitras) wrote

Peter wrote:

(Don Poitras) wrote

Both are available online. Here's the relevant section:

Where?

Do a Google for ""kln 94 pilots guide". First hit.
Ditto '"Avionics Library" bendix-king' (without the single quotes). Second
hit, dig down.

I don't verify the accuracy or legality of either of these, but I'm
sure with some digging you could find more.

Yes, excellent. I have my own slightly bigger collection but this one
is interesting.

It's also great for full US-style GPS approaches.

I am OK with it for the approach itself, but how does the waypoint
sequencing work after the MAP?

From the book:

"To perform the published missed approach procedure, press D- to bring
up the direct-to page. The default waypoint will usually be the first
waypoint of the missed approach procedure."

"Confirm this waypoint as the direct to waypoint and press ENTER."

So you get the 1st WP of the missed approach, only?

No, you get the entire missed approach to the hold. They make you hit
D- because often you need to fly a certain heading and/or reach
a certain height before turning to the first missed approach waypoint.

One Q, since you seem to know this stuff: is there *any* way to get a
KMD550 to display arcs, from the KLN94 database? Mine only ever
displays straight lines, and STARs/SIDs tend to look unrecognisable.

I don't own a KMD550, but I see someone else has answered this.

--
Don Poitras