On Oct 19, 7:38*pm, Steve Leonard wrote:
On Oct 19, 11:28*am, Mike the Strike wrote:



A steep climb on a short rope attached to the CG hook will likely
exceed the weak-link strength (1,000 pounds?) long before you get to
200 feet.

Mike-

Mike, how is the load on the rope higher if the rope is short than it
is if the rope is long,as you propose? *Answer: *It isn't. *Angle of
attack (lift) and speed determine line tension during the climb.

The difference in the long rope and a short rope is that if you assume
the same deck angle for the airplane, you get to the critical back
release angle at a much lower altitude on a short rope than you do on
a long rope. *Same climb rate with the same plane at the same speed
gives the same line tension on a rope that is 200 feet long or 2000
feet long. *You just hit max altitude much faster on the shorter rope.

There are clearly some differences in the dynamics of short vs. long
ropes. In particular, the shorter rope constrains the flight path to
smaller radius, which I assume causes a somewhat greater than normal
"water skier" effect once the glider pitches up to climb attitude. I
can imagine how a heavy SUV and short elastic rope, combined with a
slight over-rotation on takeoff, could easily degenerate into rapidly
increasing pitch angle, airspeed, lift, and rope tension...

Marc