"Andrew Warbrick" wrote in message
...
At 20:54 30 June 2005, Stefan wrote:
Chris Reed wrote:

And I should add that I was explaining the exercise
from memory and may
have got the speeds wrong. 90 kts is definitely over
the top for

Watch the limits: The LS 4 for example is limited to
77 knots on the winch.

As you are fond of pointing out, read the thread.

What Chris is describing is an upper air excercise
(no winch involved), Va and Vne are relevant, the max
winch speed is of no concern (personally I favour 70-75kts
as an entry speed, 60 isn't quite enough to get the
glider into the winch launch attitude, push over and
then stop the nose dropping on the horizon, 90 would
work but you'd be wasting height).

To simulate the situation which kills people (namely
spinning as a result of commencing a turn before flying
speed is regained after a cable break) you dive to
acquire speed, pull up into the winch launch attitude
then, at the appropriate moment, shout 'bang' and recover,
but check the pitch down at the normal gliding attitude
for 60kts, then immediately start a co-ordinated turn.
A Puchacz will immediately spin off this if you get
it right (the speeds are quite critical), too slow
you can't hold the nose up, too fast and it gets 'untidy'.
Trying to do this demo off a real winch launch would
hurt.

You guys do this a little bit more subtly than I did it. I just asked the
student to deliberately botch the simulated wire break by doing nothing at
first. Just leave the glider pointed at the sky until it runs out of energy
and the nose falls through on it own and THEN, just as the nose falls
through the horizon, yank hard back on the stick while attempting a turn.
Almost any spinable glider will spin with enthusiasm under those conditions.
Of course, I'm talking about doing this at a safe altitude.

Fiveniner's point that this is abnormal use of controls is a fact but a
rusty or inexperienced pilot already unnerved by a wire break and now seeing
the nose fall toward the earth may just do it this way if not for this sort
of explicit training. It would appear that there are several cases in the
BGA accident database where this might have happened.

Just in case there are lurkers reading this who are getting the impression
that this is a sort of trap for the unwary should carefully read fiveniner's
flight test report. It DOES require the pilot to use very abnormal, in fact
illogical, control inputs. The training just reinforces the very basic idea
that the pilot must see a safe airspeed for the glider being flown before
establishing a normal glide or attempting a turn. No rocket science here,
just mind your airspeed and use smooth, logical control inputs.

Bill Daniels