Tost release failure

No.

No matter how many or what sort of test, in the end you take off
attached to a rope whose ability to be released can't been checked.

GC


On 27/08/2012 10:00, Chris Nicholas wrote:
‘No amount of release checking will avoid a wrongly hooked on rope.
Standard reply is: "My release was checked yesterday" .’

It can do. If the ring is wrongly inserted, then all three checks are likely to expose it, which ever us done first: free drop, back release, and under tension.

These will also catch other things that may not have applied “yesterday” – different (and now wrong) ring, or damaged ring, or damage to part of the release or the cable mechanism that still allows hook up to some extent but precludes release when needed. There have been examples of all these over the years, hence the development of the three checks. Not doing them is volunteering to have some holes in the Swiss cheese.

Chris N.

On Friday, August 24, 2012 1:25:49 PM UTC-4, kirk.stant wrote:
Finally! I've been refusing to do release checks for years and get the stink-eye everytime. I've tried explaining that if you can hook up, then you have checked as much as you can, but still get people saying "but what if it fails?". Maybe one of you smart guys out there can explain the logic of a separate release check? Kirk 66

Your logic seems fine if you are flying a glider with a Tost hook that you must open in order to connect the tow rope.
But- you may be teaching the line crew not to doa check which may appy to other gliders.
Examples:
1)Tost Hook with back release can be connected by someone who knows how without the pilot pulling the knob. What if the release cable is broken or jammed?
2) Schweizer hooks are easily hooked up without pulling the knob. Same question about cable.
3) Some hooks are externally operated to hook up. 1-35, HP series, others I don't know about. Verifying functionality would seem to be wise.

I happen to tow out to the line on a rope. Releasing acts as my functional test and I don't do another at launch. I encourage our pilots to do the same to save a bit of time at launch, but ask them to tell the line person that the release check has been done.
FWIW
UH

"I encourage our pilots to do the same to save a bit of time at launch, but ask them to tell the line person that the release check has been done. FWIW UH"

Hank, I also usually tow out behind a golf cart, and that hookup/release serves as my release check. On my own ship, with a nose tost, I am comfortable that the hookup process (with rattle check) is sufficient. I will defer to more experienced pilots when it comes to checking CG/back-release hooks. I also tell the line that the check has already been done.

Oddly, my two release failures in over 2000 hrs have both been Schweizers: A PTT in a 2-32 when the release arm didn't seat all the way due to some mud on it and resulted in a surprise PTT at barely 200' - I was in the RCP giving a ride and didn't check the altimeter - but the result was a rapid 180 and return to the launch point for a second (successful) flight; the other was a jammed release when a tost ring was used on a Schweizer hook (2-33) - a practice since discontinued, fortunately - and the little ring somehow jammed the release during the tow. Solved by getting some slack in the line, but the first time I tried to release the knob didn't move at all! On both those occasions a release check was performed and passed. So perhaps my point of view is a bit jaundiced ;^)

Cheers,

Kirk
66

That's a very good point about hooking up the Tost (belly hook) without
pulling the cable. The line crews where I fly now do not know that you can
do that so the hookup always includes: "Open", "Close", "Check". Since I
know the rope was attached in that fashion, I decline the check. If I'm
hooking up myself before getting strapped in (no line crew) then I'll check.


"kirk.stant" wrote in message
...
"I encourage our pilots to do the same to save a bit of time at launch, but
ask them to tell the line person that the release check has been done. FWIW
UH"

Hank, I also usually tow out behind a golf cart, and that hookup/release
serves as my release check. On my own ship, with a nose tost, I am
comfortable that the hookup process (with rattle check) is sufficient. I
will defer to more experienced pilots when it comes to checking
CG/back-release hooks. I also tell the line that the check has already been
done.

Oddly, my two release failures in over 2000 hrs have both been Schweizers: A
PTT in a 2-32 when the release arm didn't seat all the way due to some mud
on it and resulted in a surprise PTT at barely 200' - I was in the RCP
giving a ride and didn't check the altimeter - but the result was a rapid
180 and return to the launch point for a second (successful) flight; the
other was a jammed release when a tost ring was used on a Schweizer hook
(2-33) - a practice since discontinued, fortunately - and the little ring
somehow jammed the release during the tow. Solved by getting some slack in
the line, but the first time I tried to release the knob didn't move at all!
On both those occasions a release check was performed and passed. So
perhaps my point of view is a bit jaundiced ;^)

Cheers,

Kirk
66

On Saturday, 25 August 2012 04:14:20 UTC+2, Andreas Maurer wrote:
On Fri, 24 Aug 2012 10:25:49 -0700 (PDT), "kirk.stant"
Snip

He did a winch tow in an ASW-19. The small ring of the tow cable was
not put into the tow hook, but jammed between the Tost release and its
steel attachement structure, creating an extremely strong and
permanent connection. Mistake of the student pilot who did the hookup.

Snip

- Check the ring if it fits perfectly (it should have just a little
play)

Snip

Cheers

Andreas

The club I fly at do the three checks for the CG hook for winch launching and a single tension release check for aero tows on the nose hook.

What I'd like to highlight is that you're the only person in this thread who has mentioned checking for play once the ring is inserted.

We have a standard "rattle check" on hookup.
If the ring does not rattle from side to side once hooked up it is assumed to be jammed from being inserted wrongly and is thus released and reinserted.

Paul