Tost release and chain links

[Ramy[_2_]]

Chain links are often used instead of TOST rings for ground tows behind golf carts, as they are much cheaper. I noticed today that I can easily slide the chain link out of the nose hook of my glider without pulling the release, while in other gliders I can’t. Looks like my release has slightly more play, enough for the chain link to release, but not enough for the Tost ring which seem secured thanks to its larger size and thickness. Do other had such experience? Is there a reason to be concerned?

Ramy

[Jim[_33_]]

On Sunday, March 25, 2018 at 11:34:44 PM UTC-7, Ramy wrote:
> Chain links are often used instead of TOST rings for ground tows behind golf carts, as they are much cheaper. I noticed today that I can easily slide the chain link out of the nose hook of my glider without pulling the release, while in other gliders I can’t. Looks like my release has slightly more play, enough for the chain link to release, but not enough for the Tost ring which seem secured thanks to its larger size and thickness. Do other had such experience? Is there a reason to be concerned?
>
> Ramy

Maybe there is no reason for concern if the chain link is used only for towing on the ground - unless using the chain link damages the Tost.

But, some years ago, when I was even more stupid than I am now, I had two, low altitude premature tow line releases when the chain link at the end of the tow rope slipped out of the Tost. I had carefully examined the weak link and ignored the metal link! Haven't done that since.

[JS[_5_]]

On Monday, March 26, 2018 at 6:42:09 AM UTC-7, Jim wrote:
> On Sunday, March 25, 2018 at 11:34:44 PM UTC-7, Ramy wrote:
> > Chain links are often used instead of TOST rings for ground tows behind golf carts, as they are much cheaper. I noticed today that I can easily slide the chain link out of the nose hook of my glider without pulling the release, while in other gliders I can’t. Looks like my release has slightly more play, enough for the chain link to release, but not enough for the Tost ring which seem secured thanks to its larger size and thickness. Do other had such experience? Is there a reason to be concerned?
> >
> > Ramy
>
> Maybe there is no reason for concern if the chain link is used only for towing on the ground - unless using the chain link damages the Tost.
>
> But, some years ago, when I was even more stupid than I am now, I had two, low altitude premature tow line releases when the chain link at the end of the tow rope slipped out of the Tost. I had carefully examined the weak link and ignored the metal link! Haven't done that since.

A thinner ring can escape from the release, or as I discovered not release under tension without some wiggling. In my case the latter was after a landing on tow in an ASK21. The chain link sat entirely on the non-moving part of the nose release and was happy to stay in place with the release held open.
This could happen with a chain link or worn Tost ring.
Jim

[CindyB[_2_]]

On Sunday, March 25, 2018 at 11:34:44 PM UTC-7, Ramy wrote:
> Chain links are often used instead of TOST rings for ground tows behind golf carts, as they are much cheaper. <snipped part>

> Do other had such experience? Is there a reason to be concerned?
>
> Ramy

On the ground, not as much for concern..... unless you are towing on non-level ground and don't want the glider to escape the towing vehicle. A single person on a tip and an unleashed glider might result in ground handling damage.

Chain links for Tost hooks in flight are a bad, BAD idea.
They can release when wanted connected.
They can remain connected when wanting a release (by binding on the beak).

Chain link is typically not a hardened material.
The softness will allow a chain link to be eroded over time in using on a hard Tost beak inside the round collar. Eventually it will conform to the shape of the beak, and not slide off easily. Particularly under normal tow tension.

There is a reason the Tost ring pair has a ROUND ring for the beak. And it is
more expensive due to the process of hardening, and inspection after making.
In this case, please use the right part for the job!

I was once consulted by an AS-K 21 owner that was considering cutting out the
Tost assembly to remount in a different angle, due to the chain links not releasing under aero tow. I told them they could use Tost rings and throw them away every year for the price of cutting up and changing their glider's nose.
They began buying Tost rings.
JS knows the origin of that tale....
True story.

Cindy B

[AS]

On Thursday, April 5, 2018 at 2:50:21 PM UTC-4, CindyB wrote:
> On Sunday, March 25, 2018 at 11:34:44 PM UTC-7, Ramy wrote:
> > Chain links are often used instead of TOST rings for ground tows behind golf carts, as they are much cheaper. <snipped part>
>
> > Do other had such experience? Is there a reason to be concerned?
> >
> > Ramy
>
> On the ground, not as much for concern..... unless you are towing on non-level ground and don't want the glider to escape the towing vehicle. A single person on a tip and an unleashed glider might result in ground handling damage.
>
> Chain links for Tost hooks in flight are a bad, BAD idea.
> They can release when wanted connected.
> They can remain connected when wanting a release (by binding on the beak).
>
> Chain link is typically not a hardened material.
> The softness will allow a chain link to be eroded over time in using on a hard Tost beak inside the round collar. Eventually it will conform to the shape of the beak, and not slide off easily. Particularly under normal tow tension.
>
> There is a reason the Tost ring pair has a ROUND ring for the beak. And it is
> more expensive due to the process of hardening, and inspection after making.
> In this case, please use the right part for the job!
>
> I was once consulted by an AS-K 21 owner that was considering cutting out the
> Tost assembly to remount in a different angle, due to the chain links not releasing under aero tow. I told them they could use Tost rings and throw them away every year for the price of cutting up and changing their glider's nose.
> They began buying Tost rings.
> JS knows the origin of that tale....
> True story.
>
> Cindy B

>> They can remain connected when wanting a release (by binding on the beak). <<

Couldn't agree more with you, Cindy! Just to elaborate as to why that happens: a normal chain link at yielding load will deform and assume a hour-glass shape. That action nicely swages the link onto the beak.
Heavy duty chains like anchor chains or coal-plow chains have an insert on the inside in support of the link.
The old Tost double ring pair had a small oval ring which connected to the beak. They changed that for exactly the reason described above.

Uli
'AS'

[Jonathan St. Cloud]

I fly from an operation that uses chain links on their tow ropes. When I fly my bird I use my own weak link bridle with tost. If I travel to another location I always check what is on the end of the rope as if they don’t use a tost I will use my weak link. Just wondering how many places actually use chain links?

[[email protected]]

On Friday, April 6, 2018 at 5:38:51 PM UTC+1, Jonathan St. Cloud wrote:
> I fly from an operation that uses chain links on their tow ropes. When I fly my bird I use my own weak link bridle with tost. If I travel to another location I always check what is on the end of the rope as if they don’t use a tost I will use my weak link. Just wondering how many places actually use chain links?

Its not still April 1st is it??

[Jonathan St. Cloud]

No it is not April 1.

[Michael Opitz]

At 20:51 06 April 2018, Jonathan St. Cloud wrote:
>No it is not April 1.
>
I recall a fatal accident involving a Blanik in northern New England
where a chain link was supposedly used by the operators on the tow
rope... It has happened. People are cheap, and don't want to pay
for the Tost links if they think they can get away with something
cheaper. If you find an operation that does this, it might behoove
you to look around some more, as there may be others areas where
the operation is lacking in safety awareness as well.

RO

[son_of_flubber]

On Friday, April 6, 2018 at 12:38:51 PM UTC-4, Jonathan St. Cloud wrote:
> I fly from an operation that uses chain links on their tow ropes.

One of the pilots I know who 'has seen it all' likes to point out:

'lots of time, it is the stupid **** that kills people'.

Simple avoidable stuff kills people. Chain links on tow ropes is a perfect example.

[Ramy[_2_]]

Thanks for all responses. Seeing how easily a chain link can slip of the Tost release I find it hard to believe that anyone would tow with a chain link.
My concern was more from the fact that my Tost hook seem to have more freedom than other Tost hooks, enough to make the difference on the ground with a chain link but not enough freedom for a Tost ring to slip through.

Ramy

[[email protected]]

I seem to remember a similar thread that mentioned minimum diameter of the Tost ring. Not the overall size, but the diameter of the metal that is captured by the release itself. The recommendation was to check the ring with calipers or a micrometer to make sure that the ring had not worn down to the point that it could be inadvertently pulled out of the mechanism. I have not been able to find reference to a minimum size. Anybody know the specification?

[Eric Bick (ZN7)]

On Saturday, April 7, 2018 at 5:47:48 AM UTC-6, wrote:
> I seem to remember a similar thread that mentioned minimum diameter of the Tost ring. Not the overall size, but the diameter of the metal that is captured by the release itself. The recommendation was to check the ring with calipers or a micrometer to make sure that the ring had not worn down to the point that it could be inadvertently pulled out of the mechanism. I have not been able to find reference to a minimum size. Anybody know the specification?

http://wingsandwheels.com/tost-double-tow-rings.html

[Dan Marotta]

I seem to recall that back in the '80s Tost rings cost that much, if not
more.Â* A bargain by today's standards!

I also recall lots of folks using chain links on ground handling ropes
to move their gliders around on the airport.Â* This was before the wide
spread use of tow bars.Â* My partner and I used a Tost ring on our ground
handling rope.

On 4/7/2018 8:06 AM, Eric Bick (ZN7) wrote:
> On Saturday, April 7, 2018 at 5:47:48 AM UTC-6, wrote:
>> I seem to remember a similar thread that mentioned minimum diameter of the Tost ring. Not the overall size, but the diameter of the metal that is captured by the release itself. The recommendation was to check the ring with calipers or a micrometer to make sure that the ring had not worn down to the point that it could be inadvertently pulled out of the mechanism. I have not been able to find reference to a minimum size. Anybody know the specification?
> http://wingsandwheels.com/tost-double-tow-rings.html

--
Dan, 5J

[[email protected]]

Ramy,
If the effort to pull the release, seems to be less, you may have a broken spring. There are two return springs, one on each side of the Tost release. For ground towing, I'd get a chain that measures 1/4" thick X 1" X 1.5".............the cost of new Tost rings ($44.00) means they are used forever........I remember seeing one that was older than dirt and had failed at 2 places, 180 degrees apart.
Hope this helps,
JJ

[kirk.stant]

Of course, there is the reverse problem - I used to fly at an operation that did a lot of commercial rides with a fleet that included several 2-33s and G-103/ASK-21s, and supported a pretty large fleet of private owners (mostly Tost-equipped). They were using the Tost links on the 2-33s to save time finding and switching straws with the correct links - they used the large ring on the Schweizer release arm. It kinda fit, and WTF, it's a Schweizer, right?. One day while giving a ride from the back seat of a 2-33 I got to release altitude and found that the release was completely jammed - no movement at all. No radio, of course, so I moved out to the left and rocked my wings, at which point the tow pilot released his end. As soon as the rope tension was released, my release un-jammed and the rope disappeared into the desert never to be found again.

After the flight we figured that sometime during the flight (probably bumping along during takeoff) the small ring had flipped back and over the release arm, so now the entire pull force of the tow was keeping that arm from moving aft and releasing the rope! Of course, as soon as the rope was released by the tow pilot, it moved back in the release, the small ring slipped off the arm, and the hook back released as designed.

Shortly after that incident a bunch of new straws with proper Schweizer tow rings appeared and were used from then on.

TL:DR Use the right tow link for the right tow release!

Kirk
66

[Michael Opitz]

I am somewhat amazed that nobody in this thread has pointed out the
mechanical design elements in the TOST release system. In addition to
the strength of the steel without the welds, the two different sized links

are designed to work with the Tost release so that the big ring rides on
the release outer ring, thus making sure that no matter what angle the
rope is being pulled at, the geometry is such that the smaller ring is
always pulling straight out and thus can't ever jam the hook due to side
or other loads. Two same sized chain links just can't accomplish this.
The two same sized chain links defeat the safeties that Tost has built
into their release system. Not using the approved links for flight
operations is just dumb and dangerous. I'd bet that there would also
be pretty big legal ramifications if there were an accident where a
release issue was at least a contributing factor, and the investigators
found out that the glider was not being operated according to the
glider/TOST operating manual specifications.

In our club, we have TOST links on our ropes. If someone wants to fly
the 1-26, we have a single Schweizer ring on a short rope weak-link /
pig-tail which we thread onto the larger TOST ring for temporary use.

RO