In article m6YKb.427104$J77.33562@fed1read07,
Greg Arnold wrote:
Marc Ramsey wrote:
If these figures aren't available, is the use of CG hooks being
discouraged based simply on the assumed lack of positive longitudinal
stability during aerotow?
Is the pull on a CG hook during aerotow ever great enough to have much
effect on the longitudinal stability of the glider? I have never
noticed such an effect, so I wonder if pilots who fly from a winch (very
quick acceleration and doubtless a significant effect on longitudinal
stability) are unfairly extrapolating their experience there to the
aerotow situation.
Doubtless a nose hook is better for aerotow, but I wonder if the alleged
advantages aren't being oversold by some posters to this thread.
I've done 36 aero-tow flights in an original model Janus with only a
CofG hook. It's hard to say wihtout being able to try it on a nose hook
but I think the feel-free flying tailplane is a *much* bigger issue with
it than the belly hook. I've noticed a pitch-up tendency as a slack
rope comes tight, but it's always been minor and easily allowed-for.
A couple of days ago I had an opportunity to do a winch launch in the
same model of Janus. Even with a powerful winch (far greater
acceleration than a tow plane), it was easy to hold the glider level
just after it became airborne, and it took positive action to go into
the climb.
I think my attitude towards aero-towing in the Janus is summed up by:
- it's not a problem if you're alert, and it hasn't been a problem even
when I haven't flown anything for 1 - 2 years and then fly the Janus
first-up.
- if it cost in the region of US$1k to put a nose hook on the Janus
then I'd probably think that it was worth doing as a form of insurance.
- I think I'm glad I'm not an instructor trying to teach aerotowing in
it :-)
All in all I think it's just one of those things that contribute to the
Janus providing a noticably higher piloting workload than, say, our Twin
Astirs, but all the same I'll fly it in preference any day of the week.
-- Bruce
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