Cambridge L-Nav audio vario just ate it...

On Nov 13, 4:26*pm, Papa3 wrote:
On Nov 13, 5:50*pm, Bruno wrote:

On my last flight my audio vario suddenly started to read a consistent
300-400 fpm too high for the present conditions. *I have a mechanical
vario that remained accurate and on my L-Nav screen my average fpm
sink rate was correct. *Any ideas what I can check? *It was really
annoying when I was sinking at a true 300 fpm on glides but my audio
was telling me I was going up 100fpm. *If only it was always that way
in real life! *

Thanks,
Bruno - B4

Hi Bruno,

What you wrote is a little confusing. *I wonder if you meant that the
dial was showing high along with the audio tone, while the LNAV LCD
screen showed a believable average (and netto)? * *As you probably
know, it is possible to adjust the zero and gain on the vario through
the configure screen, and the manual tells you what the acceptable
zero number ranges are. * *It would at least be interesting to have a
look at those values and see what they show. * But, it wouldn't
explain (at least to me) while the dial and audio are out of sync with
the other values.

Sounds like a trip to NK is in order.

P3

Sorry for being confusing in my description. It is exactly as you
state. I will take a look at those values. Good idea. I wonder why
it would go so out of adjustment when it always was working properly
before?

Thanks for the ideas,
Bruno -B4

Bruno wrote:
On Nov 13, 4:26 pm, Papa3 wrote:
On Nov 13, 5:50 pm, Bruno wrote:

On my last flight my audio vario suddenly started to read a consistent
300-400 fpm too high for the present conditions. I have a mechanical
vario that remained accurate and on my L-Nav screen my average fpm
sink rate was correct. Any ideas what I can check? It was really
annoying when I was sinking at a true 300 fpm on glides but my audio
was telling me I was going up 100fpm. If only it was always that way
in real life!
Thanks,
Bruno - B4
Hi Bruno,

What you wrote is a little confusing. I wonder if you meant that the
dial was showing high along with the audio tone, while the LNAV LCD
screen showed a believable average (and netto)? As you probably
know, it is possible to adjust the zero and gain on the vario through
the configure screen, and the manual tells you what the acceptable
zero number ranges are. It would at least be interesting to have a
look at those values and see what they show. But, it wouldn't
explain (at least to me) while the dial and audio are out of sync with
the other values.

Sounds like a trip to NK is in order.

P3

Sorry for being confusing in my description. It is exactly as you
state. I will take a look at those values. Good idea. I wonder why
it would go so out of adjustment when it always was working properly
before?

Thanks for the ideas,
Bruno -B4

Backup battery? All kinds of really weird stuff happens when they go
flat. Its a little internal coin sized battery. Easily replaced.

Or the sensor could have died, which means a trip to NK...

-Dave
ZL

I am betting with ZL. Data hold battery inside the L-Nav. I had one
that did that. Of course, on the first flight of a new to me plane,
so I had no idea what the varios were trying to tell me. Not that it
mattered, as there was no lift to speak of.

Steve
ZS