"F.L. Whiteley" wrote in message
...
Ian Johnston wrote:

On Tue, 5 Jul 2005 16:57:36 UTC, "F.L. Whiteley"
wrote:

NDT would work if you jigged up an accurate test bed. I would be more
concerned with rope weak links used in aerotowing than TOST weak links
if
I
wanted to test something. From many years of observation I'm pretty
confident that the TOST links perform as expected.

Me too. Tost aerotow weak links are pretty good as well - I thought
just about everyone had gone over to them in place of rope. Mind you,
I knew one club which put a good stout length of rope in parallel with
the Tost link "because they are so expensive if they break and we lose
half the connector."

Ho hum.

Ian


--
I don't recall having seen a TOST aerotow weak link in use in the US.
Perhaps some are using them.

Frank

There's no (legal) reason not to use the Tost weak-links for air tow in the
USA as long as the strength satisfies the FAR 91.309 80%-200% rule. (Note
that 200% of the MTOW allowed by that FAR is generally much stronger than
the manufacturer's mandated winch weak-link strength.)

The POH for my Nimbus 2C states that the weak-link for air tow is the same
(92% of MTOW) as for winch launch. It's interesting to note that S-H
specifies the weak-link strength for air tow just as tightly as for winch
which may imply that the designers concern was not the wing but the tow hook
mounting structure.

Bill Daniels