At 19:24 29 June 2007, Brtlmj wrote:
structurally damage a glider during a winch launch
from overspeeding.
Providing the correct weak is used, that is not possible.
Old myths
die hard though.
Why, then, is the winch launch maximum speed not Vne?

If I understand it correctly, flying at maximum winch
speed or below
ensures that you won't lose your wings even if you
use a wrong weak
link or no weak link at all.

Bartek

VNE in free air is determined by the amount of lift
a wing can generate vs. it's load strength; ie the
wings can only generate as much lift as the spar/structure
can safely handle.--During a winch launch there is
significantly more stress for a given airspeed due
to the downward force being applied to it by the winch
pulling it, counteracting some the lift the wings are
generating. The wings generate the same amount of lift
at any given airspeed, whether on or off the cable,
but while it is attached to the cable a lot more of
the force is being directed into the airframe, since
the hook/cable is keeping it from being able to zoom
in it's normal path physics would otherwise dictate,
were it not attached at that speed; and naturally the
forces increase with increases in speed.
I have a novel idea--how about a new thread about winching,
so this one can remain on the subject: New Trainer
from SZD Bielsko. I personally ca not wait to fly one
of these beautiful new aircraft. I think it is about
time that an alternative to the K-21, 1000, Duo, and
Fox be available. It seems like it will make a great
trainer for XC, acro, or maybe even beginners that
show aptitude. All this and for much less money than
the other options (OK, priced similar to the Fox, but
the Fox is not really an XC ship). Not knocking any
of the other ships, they all have their ups and downs.
I still say hats off to SZD!!

Paul Hanson
"Do the usual, unusually well"--Len Niemi