Winter Vario

When circling at the normal thermalling speeds my Winter vario seems to
reflect the sailplane actual rate of climb however when flying at a
higher constant speed (example 100 knots) the vario does not reflect
the rate of climb. I first noticed this when penetrating into a wave
where the vario was giving a positive rate of climb (example 4 knots)
for several minutes however the sailplane continues to descend. Is
this normal?

I also have a 302 however I have developed the habit (probably bad
habit)of looking at the winter vario and I can't really say what the
302 was indicating although I believe it to be more accurate.

Hal:
Forgive me if this is obvious and you have checked it - but Winter varios
can freeze in operation due to the presence of moisture and cold
(especially from wave or spring flying). Are you sure that this is not
what is happening? It happens in my Nimbus 3 every spring for a few
flights after the winter season layover. My 302 works fine but the Winter
vario is sometimes sticks pointing in the opposite direction - and then it
"unsticks". Sunlight on the panel can make the problem go away.

Just a thought

Roy B.



Roy A. Bourgeois
Bourgeois Dresser White & Beard
4 Dix Street
Worcester MA 01609

tel: 508 798 8801
fax: 508 754 1943

Sounds like symptoms compatible with a leak on the
flask side of the vario. The faster you go the greater
the negative pressure in the TE line sucking air through
the vario so giving a false positive reading.

Also if you have mini winter vario the pneumatic connections
on the back are quite fragile and can be loosened when
pulling tubes off. That could be a leak source. I've
done that.

John Galloway


At 00:24 17 August 2005, Roy Bourgeois wrote:
Hal:
Forgive me if this is obvious and you have checked
it - but Winter varios
can freeze in operation due to the presence of moisture
and cold
(especially from wave or spring flying). Are you sure
that this is not
what is happening? It happens in my Nimbus 3 every
spring for a few
flights after the winter season layover. My 302 works
fine but the Winter
vario is sometimes sticks pointing in the opposite
direction - and then it
'unsticks'. Sunlight on the panel can make the problem
go away.

Just a thought

Roy B.



Roy A. Bourgeois
Bourgeois Dresser White & Beard
4 Dix Street
Worcester MA 01609

tel: 508 798 8801
fax: 508 754 1943