At 17:02 07 July 2014, jherzog wrote:

I have a nagging, recurring problem with my trusty L-Nav. Occasionally
when I power the unit on, the lift tone sounds constantly, and the vari
display is pegged at maximum lift (10 kts). It's clear that the proble
is with the L-Nav, and not the electric vario display, as the ton
continues to sound once the electric vario display is unplugged, and th
problem continues once the vario is plugged back in.

Cycling power once or twice will sometimes, but not always, make th
problem go away -- until the next time. Last Friday, the proble
persisted for two hours, finally disappearing as mysteriously as i
came. Once the L-Nav powers on correctly, it has always staye
operational for my entire flight.

Has anyone else experienced this, and found a solution?

Thanks,


I have exactly the same issue with my L-Nav and have concluded it is a damp
issue. The problem stopped when I put a dehumidifier in the trailer over
the winter but has recurred over this summer after a damp period. As you
say normally recycling the power stops the problem but I too have had
occassions when the unit simply screams climb for the whole flight.