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Old July 20th 09, 03:15 PM posted to rec.aviation.soaring
Don Johnstone[_4_]
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Posts: 398
Default SAFE Winch Launching and automatic gearboxes

At 11:50 20 July 2009, brian whatcott wrote:
Don Johnstone wrote:
... a "tension controlled" winch is about the craziest idea I have

ever
heard, not least because, thankfully, it would never work.


Why not?

Brian W



Because there is no direct relationship between the tension experienced at
the winch and that experienced at the glider release using wire rope.
Even with plastic rope the relationship is tenuous at best, the rope does
have some mass and in addition has an elastic quality as well. The
tensions experienced at each end of the cable can be vastly different and
are different more often than they are equal, so measuring at the winch
end tells you very little about what is happening at the glider, it may
indicate what has happened but even this is not likely to be very
accurate.