A very good friend of mine died several years ago in
a tug upset.
He was aero-towing I believe a Ka6 out of a wave site
when turbulence caused the glider to loose sight of
the tug at about 300ft. The glider pilot did not release
and the tug pilot could not as his inertia reel harness
had locked and he was unable to reach the release (conclusion
of the AAIB). The uspet was so bad that the tug was
hanging vertically from the glider before the rope
broke. The resulting dive was irrecoverable and the
pilot died when the tug hit the ground, the glider
pilot of course survived.

I recall fitting a new rear end to a Tiger Moth that
had been used for glider towing, 3 of the four rear
longerons were almost pulled completely apart. None
of the other Tiger Moths, which were not tugs, serviced
by the same organisation had the same problem. Co-incidentaly
the main pilot of the Tiger Moth was the pilot mentioned
above but he was not flying the Tiger in the incident.

The answer to the original poster is, yes they bl00dy
well are, and you would do well to remember it especially
if you are a tuggie.
Glider pilots always seem to survive tug upsets it's
the tuggie that gets it.

At 21:06 17 September 2006, Doug Haluza wrote:

KM wrote:
OK now focus here Doug, the math is not in dispute.
The question is
whether a glider could exert this force while on tow.

If both aircraft are in a steep dive from a high altitude
upset, and
the glider pilot panics and pulls the sitck, it certainly
can. But it
really doesn't matter--using a dockline as a tow rope
means it won't
break before one of the aircraft does.

But what makes you think the dive would be 'Unrecoverable'
just because
the tow plane is past its manurering speed?

The dive after an upset will be unrecoverable as long
as the glider
stays attached to the towplane.