A Rough Day Towing

I'm sure the release rope break with the rope over the wing slew that
glider sideways. The pilot could not see the damage to the leading
edge of the wing and flew 4 hours?? WTFO.

Helloooooooooooooooooo, captain CRUNCH, where are you????

Brad

What size rope were you using? Was there an weak link?

Boggs

On Tuesday, June 5, 2012 7:25:16 AM UTC-5, GARY BOGGS wrote:
What size rope were you using? Was there an weak link?

Boggs

What type of release mechanism?

The glider's release mechanism is the standard Dick Schreder design.
http://www.soaridaho.com/Schreder/Co...k/Tow_Hook.htm

Here is a photo of the mechanism as it appears in HP-14T blue-prints.
http://www.soaridaho.com/Schreder/HP..._Tow_Hitch.jpg

This hook has been very reliable for the past 50+ years. The concept has
been copied and install on other sailplane designs including the 1-35A

Wayne
http://www.soaridaho.com/Schreder



"150flivver" wrote in message
...

On Tuesday, June 5, 2012 7:25:16 AM UTC-5, GARY BOGGS wrote:
What size rope were you using? Was there an weak link?

Boggs

What type of release mechanism?

On 6/5/2012 9:27 AM, Wayne Paul wrote:
The glider's release mechanism is the standard Dick Schreder design.
http://www.soaridaho.com/Schreder/Co...k/Tow_Hook.htm

Here is a photo of the mechanism as it appears in HP-14T blue-prints.
http://www.soaridaho.com/Schreder/HP..._Tow_Hitch.jpg

This hook has been very reliable for the past 50+ years. The concept has been
copied and install on other sailplane designs including the 1-35A

And also - at least conceptually/functionally - George Applebay's Zuni design
(though some may now/have-had Tost releases); I can't speak for
dimensionally/geometrically. Difficult (for me) to imagine a simpler release
mechanism.

I never had release a release problem in 106 HP-14 and 655 Zuni aerotows. Had
1-each back release in both ships, from BIG bows in the rope...as should have
happened.

Bob W.


Wayne
http://www.soaridaho.com/Schreder



"150flivver" wrote in message
...

Snip...

What type of release mechanism?

I think the rope is 3/8 polypropylene. The rope strength is within FAA
requirements for the gliders we tow. We use a weak link with a tost ring,
but not with the Schweizer. There's a Schweizer release on the tug.


"GARY BOGGS" wrote in message
...
What size rope were you using? Was there an weak link?

Boggs

I have been a bit concerned with the ropes some places use.

http://www.engineeringtoolbox.com/po...th-d_1516.html
shows the following minimum breaking strength

1/4 1125 lbf 80%= 900 lb minimum glider weight
5/16 1710 lbf 80%= 1368 lb minimum glider weight
3/8 2430 lbf 80%= 1944 lb minimum glider weight

I prefer towing behind 1/4" rope I have seen a few rope breaks with
1/4" all seemed warranted with a rope in good condition.
It seem to me that unless you are towing a fully loaded ASG29 or a two
place that 1/4 rope is probably what should be used unless of course a
weak link is used. And even then 1/4" rope should be adequate at the
200% rating or less.
Am I missing something?

Brian

Wear on the runway, UV degradation.


"Brian" wrote in message
...
I have been a bit concerned with the ropes some places use.

http://www.engineeringtoolbox.com/po...th-d_1516.html
shows the following minimum breaking strength

1/4 1125 lbf 80%= 900 lb minimum glider weight
5/16 1710 lbf 80%= 1368 lb minimum glider weight
3/8 2430 lbf 80%= 1944 lb minimum glider weight

I prefer towing behind 1/4" rope I have seen a few rope breaks with
1/4" all seemed warranted with a rope in good condition.
It seem to me that unless you are towing a fully loaded ASG29 or a two
place that 1/4 rope is probably what should be used unless of course a
weak link is used. And even then 1/4" rope should be adequate at the
200% rating or less.
Am I missing something?

Brian