At 16:12 02 June 2012, Dan Marotta wrote:
All the concern about nose vs. CG release and the correcting force of the

nose release indicates, to me, poorly trained or lazy pilots. If you will

simply fly the aircraft and pay attention to your flight path, you'll find

that it makes no difference what type of release you have (unless you're
doing a ground launch).

[snip]

The concern in the UK about towing on CG hook when a nose hook is available
came from tug pilot fatalities. The first, and most of the other, such
accidents happened with CG hooks, and one or more of the other factors,
which led to kiting, tug upset, and tug hitting the deck. As a result, the
BGA issued a poster listing the 6 factors most closely associated with
upsets, and advised having not more that two (IIRC) such factors on any one
launch.

More recently we started to have upsets again, so far fortunately without
fatality. Unable to find the original poster, we issued another which had
the following:
-------------------
Tug Upsets

These happen when the glider suddenly zooms above the tug, putting it into
a steep dive requiring considerable height to recover.

The BGA ran a successful campaign to end these fatalities to tug pilots,
but several years without incident now appear to have ended. This year
there have been two reported upsets and at least one other not reported.
Fortunately none resulted in crashes.

Six factors make upsets more likely:

 Lightweight, low wing-loading

 C of G hooks intended for winch launching

 Short ropes

 Inexperienced pilots

 Near aft C of G.

 Turbulent conditions

If two of these are present the danger becomes significant. More than
two should be considered unacceptable.

-----------------
Chris N