"Ben Flewett" wrote in message
...
At 15:54 02 November 2004, Stefan wrote:

There is no such thing as 'trapped' by a layer if you
act
as you should.


Sounds like you haven't done much cross country wave
flying.

If you do enough cross country wave flying you will,
sooner of later, get trapped above cloud. Sometimes
you are forced to fly part of your task above 8/8 where
we fly. Other times the cloud can close quickly and
you get caught.

We were trained to position approx 1km downwind of
a known landing point using GPS (depending on terrain),
set the glider up in a stable position and open the
airbrakes at 70kts. Not desirable by any stretch of
the imagination but sometimes a required technique.


I have to agree with Ben.

I got caught above a cloud deck in wave once. It wasn't that the deck
'moved in" below me, it just formed very quickly. One moment there was a
scattered lenticular deck at 22,000 and the next there was a solid deck
below me at 12,000. There was never an option to escape VFR.

Having neither radio nor gyros, I was in no hurry to try a descent either by
benign spiral or in a stable spin so I just sat there and maintained my
position in the wave. The cloud tops marked the wave nicely. After about
an hour, the patch of moisture moved off downwind and a foehn gap appeared
in the cloud deck below. Descending through the gap meant fighting my way
down through the strong lift with full spoilers in a dive. It took almost
an hour.

I'm a believer. Sooner or later, you'll need the ability to make a blind
descent.

Bill Daniels