"Ian Johnston" wrote in message
news:dzZo7CxomoOm-pn2-1IU6gvmrdIOd@localhost...
On Tue, 5 Jul 2005 15:59:24 UTC, M B
wrote:

Is there any commonly known way to test a weak
link non-destructively (other than launching a glider)?

The Tost system uses two in parallel, one slightly longer than the
other. Whoever hooks up the glider should always check that both links
are intact and that only one is taking the load.

Ian

To expand on what Ian wrote, the parallel weak-link system places only the
primary weak-link under load with a unloaded spare in place to take the load
should the first one fail below its rated strength as a result of fatigue
from repeated load cycles. If the failure is due to an overload, the spare
will fail a millisecond after the primary and the glider will be protected
from excessive cable force.

If the person hooking up the glider to the winch line shows these weak links
to the pilot, a crack in the primary will be obvious and can be quickly
replaced with a new one of the correct strength for the glider.

The Tost weak-link system is very well thought out and correct weak-link
color is universally referenced in German glider handbooks. It should be
used in every winch operation. I find it very comforting to know that the
glider will be protected from excessive loads while the weak-link itself is
backed up by a full strength spare.

Using either over or understrength weak-links is very hazardous.

Bill Daniels