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Old June 2nd 10, 03:00 PM posted to rec.aviation.soaring
bildan
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Posts: 646
Default Use of weak links

On Jun 2, 2:43*am, Paul wrote:
Currently the club that I am part of don't seem to be too concerned about
the safety aspects of using the correct weak links for winch launching
and I'd like to know how safe it is.

Currently I see two issues with the winch launching:

1. Sometimes a weak link is not used at all. The gliders are attached
directly to the winch cable (via drogue chute and various connectors).

2. When a weak link is included in the cable (only a primary link - no
reserve link) it is used for all glider types (G102 Astir, G103 Twin II,
ASW20, LS4) and I'm not even sure what the breaking strain is. My guess
is it's a Tost #1 black (1000 daN) weak link but that's hard to tell
because its weathered and the protective sleeve obscures the Tost number.
The weak link is never changed between glider types.

According to what I have read (glider manuals and Tost manual) the
maximum winch load that should be exerted on most of the single seaters
is 500 daN and on the G103 Twin II it's 750 daN.

Am I being paranoid about safety? Are weak links not that important for
safe winch launching?

I took the matter up with the safety officer who said I need to take it
up with the CFI but I'd like to get some advice and input before I engage
with the CFI over the matter.
I'm new to soaring so I don't know it all.

Thanks


You are not alone. There is a terrible casualness about weak links
out there.

The FAR's are clear. FAR 91.9(a) says if your glider has an Aircraft
Flight Manual which is part of the airworthiness documentation, you
must operate in compliance with that manual. AFM will mandate a
precise (+or- 10%) weak link for both aero tow AND winch launch. As a
practical matter, the best way to comply is to use a steel Tost weak
link. Knots and bits of rope just don't make the grade.

Not using the correct weak link is not only an FAR violation, it
violates common sense. Operators are NOT free to choose their own
weak links.