Winch Launch Safety Study

On Mar 21, 9:29*pm, wrote:
Bill,
I also wonder if you have considered gusts and turbulence on elevator
authority. The winch RPM speed is not affected by this and will
continue accelerating if that 's what you want, when gusts or
turbulence affect the elevator. Even Tension controlled winches may
not be able to reduce tension quickly enough if this happens. That's
why the initial tension should not be too high to begin with.

RPM is of interest only as far as it is necessary to protect the
engine. It is of no interest in the launch profile. Properly
engineered automatic tension control winches can for all practical
purposes INSTANTLY reduce or increase tension in response to gusts.

I would like to hear your description of how winch settings should be
with some metrics. I know you advocate high initial tow acceleration
launches. But that doesn't really tell me the specifics.

Tension, and therefore acceleration, is limited by the prescribed weak
link strength to no more than about 1.2 G. George Moore has
extensively studied this and shows that a slight tension reduction at
rotation is needed although more actual measurements are needed to
validate that.