On Tue, 29 Jul 2003 08:05:21 -0600, "Bill Daniels"
wrote:


"Dave Martin" wrote in message
...
The danger here is that we are talking theory where
we may start to confuse pilots. It is harder to stall
with 60 degrees of bank. Gliders like the K13, by
design run out of elevator in straight and level flight.
They are difficult when flown with heavy pilots to
develop more than a mushing stall in sraight and level
flight.

Put light -- bottom weigh pilots in and they become
a different glider.

The Puchacz on the other hand has plenty of rear elevator
even when banked, quite steeply.

There can be some dangerous assumptions that gliders
will not spin.

The pilot must know the limitations and characteristics
of the glider he/she is flying. This can only be achieved
by carefully experimenting with different configurations
and different flight situations.

Gliders with reputations that they will not spin, can
catch pilots out who load them wrongly, fly them badly
or worse combine both.

Dave Martin

You make a good point. Some gliders are very resistant to stalls and others
will stall readily - especially with light pilots. It seems that trainers
made in Eastern Europe come equipped with large, effective elevators that
can stall the wing in any attitude. On the other hand, many German single
place glass gliders often have small elevators with limited up authority.

For example the Blanik L-23, IS28 b2 Lark and, as another poster pointed out
the Puchacz, can be stalled from a steep bank easily. For this reason, they
make good trainers since the student must learn to be constantly aware of
pre-stall buffet.

However, the point the Derek was making is that it is more difficult, but
not impossible, to stall in a steep turn. I've had this discussion with
pilots who feared steep banks. I suggest that thermalling is steep banks is
easier in that the glider is more difficult to stall and fewer corrections
are needed to stay in the thermal since the turn diameter is smaller.

Bill Daniels

This is an extremely important caution. Gliders do not all have the
same behavior. Along this line, I have been cautioned that in a turn,
the inside wing, even in a coordinated turn, is flying at a higher
angle of attack than the outside wing. The degree of difference would
vary with the bank angle. Thus, some gliders may not only stall in a
steep turn, they can flick into a spin "out the bottom" in the blink
of an eye. This may not be the case with many (most?) "modern"
ships, but none-the-less is worth keeping in mind I guess.