tow hook limitation question

On Feb 4, 10:54 am, "Jim Vincent" wrote:
wrote in message

oups.com...



Several years ago in soaring magazine
there was an article about a glider kiting and the
tow pilot was unable to release. However the cause
was not that the schweizer release jammed, it was the
result of a poorly installed and secured release cable
housing. The cable ties used to secure the release
cable housing to the airframe failed, which then resulted
in excessive slack in the release cable. This excessive
slack meant that the tow pilots release handle was
incapable of pulling on the schweizer release lever.

Many years ago there were tests of Schwiezer releases that showed that
they did, indeed jam. These should all be replaced ASAP. Anyone with
a brain can look at a Schwiezer release and see why it will jam under
high loads.

2c

I'll bite....why will it jam under high loads?

This is extremely difficult to describe without a diagram, but the way
the release is constructed causes pressure to be applied to the
mechanism in such a way that higher forces are required in the cockpit
as upward pressure on the mechanism is applied (towplane low, glider
high). Too much pressure can cause this force to be great enough that
the pilot will not be able to deliver such pressure in an emergency
situation.

2c