Interesting. What sort of telemetry equipment are you using? I had
proposed this several years ago but the consensus was that it would be too
expensive to equip each glider with a telemetry transmitter. Constant
tension puts all the sensors at the winch and requires no extra equipment in
the glider.

George Moore has written a series of excellent papers on automatic control
of winch launches. George favors the constant tension approach but with
cable speed regulation in the ground roll and rotation phases to prevent
overspeeding the glider. These papers are available for download from the
files section of the Yahoo group "winchdesign".

Bill Daniels


"alex8735" wrote in message
oups.com...
I personally don't think that a constant force regulation results in an
ideal winch tows. I have observed a number of tows in which the glider
was initially accelerated to quickly so that the pilot reacted by
maintaining a low climb angle. This low angle results in lower force
measured by the winch and leads to a further increase of power. In a
Ka8 nearing Vne the only possible action is to abort the tow.

At our airfield we use a system which transmits the airspeed of the
glider to the winch operator. Pared with a good winch operator and a
powerful winch, this results in very good winch tows.