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Old March 7th 11, 11:46 PM posted to rec.aviation.soaring
Bruce Hoult
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Posts: 961
Default Aerodynamics of aero towing

On Mar 8, 4:24*am, Mike the Strike wrote:
I find my Discus 2 won't high-tow very well below 60 knots, even
though its stall speed is nearer 40 or 45. *One strategy I use if the
tow plane won't or can't speed up is to descend into low tow, which
buys an extra 5 knots or so.


I suspect you're flying the tow too high behind a powerful tug that is
climbing at a steep angle e.g. flying with the tug on the horizon
rather than just above its slipstream.

The rope can't possibly make enough of a difference to the lift needed
from the wings to make a difference of 5 knots, but it can make you
run out of elevator power.

If low tow is ok then a high tow just above the slipstream will be
too.