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

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

Look for internal leak on capacity side of fate of climb sensor.
Connected with tubing which gives up. TE suction causes flow through
sensor.
Good luck '
UH

Ah, yes, the "fate of climb" sensor. I've got a whole new respect for
"final glide", now.

-John

On Nov 15, 3:01 pm, wrote:
Look for internal leak on capacity side of fate of climb sensor.
Connected with tubing which gives up. TE suction causes flow through
sensor.
Good luck '
UH

I had a problem with my LNAV some years ago. Can't recall details but
might have been similar symptoms to yours and caused by a faulty G-
meter. Turns out (1) I had a spare G-meter because mine had acted up a
few years earlier; I had contacted CAI, and they sent me a new one
that I never installed because the problem went away; and (2) I was
flying a regional at Sugarbush, VT, HQ of CAI at the time! Dave Ellis
himself came over after I landed and installed the new G-meter and
returned the software offsets the proper values (I had changed them in
the air that day in an attempt to "fix" the problem). He also wired up
my old Magellan handheld GPS (this was many years ago) so I had
automatic wind for the first time.

If you're into tinkering, I suppose you could remove the G-meter (it
just plugs in) to see if that makes the problem go away. I don't have
the manual in front of me but you might have to reconfigure the
instrument to work properly. Anyone have a thought on this?

Chip Bearden
ASW 24 "JB"
USA

On Nov 18, 2:32*pm, Chip Bearden wrote:
I had a problem with my LNAV some years ago. Can't recall details but
might have been similar symptoms to yours and caused by a faulty G-
meter. Turns out (1) I had a spare G-meter because mine had acted up a
few years earlier; I had contacted CAI, and they sent me a new one
that I never installed because the problem went away; and (2) I was
flying a regional at Sugarbush, VT, HQ of CAI at the time! Dave Ellis
himself came over after I landed and installed the new G-meter and
returned the software offsets the proper values (I had changed them in
the air that day in an attempt to "fix" the problem). He also wired up
my old Magellan handheld GPS (this was many years ago) so I had
automatic wind for the first time.

If you're into tinkering, I suppose you could remove the G-meter (it
just plugs in) to see if that makes the problem go away. I don't have
the manual in front of me but you might have to reconfigure the
instrument to work properly. Anyone have a thought on this?

Chip Bearden
ASW 24 "JB"
USA

You have to install a jumper across a couple pins when G meter is
removed.
Did once with help from ex Cambridge guy. Gary K at NK would know this
ine.
UH