On Thursday, December 14, 2017 at 2:00:23 PM UTC-8, John Foster wrote:
Why do so many gliders seem to have multiple varios? Is it that critical to have a back-up for this instrument? Do they often fail and leave you in "
the lurch"?


Physiological warfare.
Feeling of inadequacy/vario envy.
Folks wanting multiple things like different time constants/settings.
Display of "other stuff" when the displays start being multi function displays.
Alternate source, e.g. electronic comp vs TE probe
Hiding ugly holes in the panel.
Backup (they really don't fail often if looked after).