At 02:30 15 December 2016, wrote:
Having the tailwheel rolling along the ground with=20
the mainwheel several feet in the air is not, and never should be,=20
considered a normal winch launch.

Absolutely true, but counter-intuitively, the only way this could happen
is with low acceleration. High acceleration means high rope tension
which
acts to pull the nose down if the tailwheel is still rolling.


Not really. Where you go wrong is assuming that the tailwheel is the centre
of rotation -
it isn't, it's an arm hitting a limit.

If you look at videos of winch launch takeoffs frame-by-frame you'll find
that it's not unusual to see the main wheel a few centimeters off the
ground while the tailwheel is still rolling on the runway. The ASK-21
photo in
the paper is typical of this. The duration of a "spur roll" is usually
onlya few frames of video so it's very hard to catch with a still camera.

One can get these videos with a YouTube downloader. Then, the file can
be
played back frame-by-frame.