tow rope brake practice crash, what can we learn...

On Jul 13, 3:01*am, Cats wrote:
On Jul 12, 3:11*am, Tony V wrote:
snip



Forgot point number 3. You can't just point the nose down and start your
turn back to the airport. You have to wait until you have enough
airspeed to pull that off. Something that gets drilled into every winch
student (I hope).

Interesting. *In my own glider a typical tow speed is somewhat above
best l/d speed so the first things would be to lift the nose slightly
and trim for approach speed. *It's a typical 15m unflapped glass
glider so 60 knots is fine, typical tow speeds are 70-80 knots.

Yes, tow speeds are usually greater than approach speeds.....this
means simply that you have "energy" in speed....

In practice at altitude, we often make a 180 degree turn off of tow,
with no loss of altitude.....and just a slight loss of speed...as you
say, staying at or above best l/d speed..We can even do a gently
climbing turn off tow, at altitude, and gain maybe 100' while slowing
from tow speed to best l/d or even slow to min sink. But I would not
recommend this near the ground.

Another point to consider, the faster the speed in a turn, the larger
the radius of turn......there may be some benefit to a slightly slower
turn (but not too slow).

We know that angle of attack is the concern in stall avoidance....any
stall spin accident off of low rope break has to have had too much
angle of attack, one way or another....This means too much stick back
pressure....This is why I like to see an obvious stick forward and
nose pitch down reaction upon rope break.....also smooth control
inputs....

But speed (suffecient speed) is also necessary for good control,
handling, dealing with gusts etc.

I think you did miss one slight concept however, that when we are on
tow, our attitude is slightly more nose up at a given speed, than what
the nose attidude would be at the same speed while not on
tow.......thrust is the variable ....

Most gliders tow with a slight nose up attitude....So if you release
from tow, and maintain the same nose attitude, or even raise the nose
further as you suggest, I think you will find a rapid decrease in
airspeed...not to mention that the thought of raising the nose while
turning, while low, just sends shivers down my spine.....

On a rope break, I instruct my students to establish the same nose
down attitude that would be used in a "normal" pattern. I find that
making the turn seems to work out well for most pilots, but the
decision making after the completion of the 180 is often
lacking......they do not recognize the problems associated with a down
wind landing...(use of spoiler and need for slip for instance)

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