Tost release and chain links

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

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.

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

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

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.

TLR Use the right tow link for the right tow release!

Kirk
66

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

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

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'

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?

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??