Aerotow towrope instructions

Hi,

I am trying to find a good online resource with instructions for assembling
a glider aerotow towrope. I can't seem to find anything. I suspect that
every soaring club has a document explaining how they make their towropes.
I'd love to have links to a few on my web site.

Best Regards,

Paul Remde
Cumulus Soaring, Inc.

Hi Paul,

I learned how to make tow ropes by reference to The American Soaring
Handbook. Perhaps you still have a copy (I donated my copy to Sundance
Aviation at Moriarty). It might also be available in the SSA archives.

Good luck!

Dan

On 4/4/2016 4:17 PM, Paul Remde wrote:
Hi,

I am trying to find a good online resource with instructions for
assembling a glider aerotow towrope. I can't seem to find anything.
I suspect that every soaring club has a document explaining how they
make their towropes. I'd love to have links to a few on my web site.

Best Regards,

Paul Remde
Cumulus Soaring, Inc.

--
Dan, 5J

We use 7/16 inch 3ply polypropylene, 200ft long, eye splice in each end. Weak links are 1/4 inch 3ply polypropylene, eye splice in each end, one eye splice holds the appropriate tow ring. Slip the eye splices together on each end of the heavier rope.

Auto tow ropes are 5/16 inch 3ply polypropylene, normally 3 600ft lengths with inline splice, for 1800ft length, eye splice on each end.
Add appropriate weak links.

Any solo student should be able to make a weak link in 10 minutes or less.
Sorry, we do not have a video.

BillT

Hey Bill, do you have a supplier for your tow rope 7/16 and 5/16? We are looking for 5000' of it for a reverse auto tow ops? I assume you are using braided polypro as you mention "splice"

CH
cliffhilty(at)netzero(dot)net

Don't have time for a lengthy reply, however, we use a combination of very strong on the primary length and not so strong on each end.

The long, too strong part is sold by Samson Rope, and is called Tenex. We use 1/4 inch for most gliders. Each end has a short section of 1/4 inch Polypropylene (about two feet) serving as the required weak links. No kind of knots are permitted.

The ropes used on the ends as weak links must pass a breaking strength test using a simple lever arm and weights to verify the rope meets the breaking strength requirements.

A major problem is the quality of the rope. In some cases the brand new rope has broken strands, or knots on individual strands, which causes the rope to fail during breaking tests.

Probably a good magazine article.

Tom Knauff

Cliff, We are using 3 ply twisted polypropylene, not the braided variety. Braided does not last in our environment. Standard splicing methods. I'll send you a PM.

BillT

Tom, we get our rope from an industrial supplier of safety and climbing equipment, the rope has to meet specs.
The 1/4 inch 3 ply twisted poly meets specs for FAA weak link requirements for most gliders. The Janus C requires a stronger weak link, so we use 5/8 ind dia for that. We also use 5/8 inch for auto tow. We could use 5/8 for aero tow, but it does not stand up very well to the abuse.

BillT

I should have added, we also install a "Whiffle" ball (lots of holes) on the glider end to protect the tow ring and also have a short length of clear plastic tubing (couple of feet more or less) that covers the poly rope. This clear tubing slides easily on the rope so it can be inspected.

Tom

On Wednesday, April 6, 2016 at 6:35:43 AM UTC+3, Bill T wrote:
Tom, we get our rope from an industrial supplier of safety and climbing equipment, the rope has to meet specs.
The 1/4 inch 3 ply twisted poly meets specs for FAA weak link requirements for most gliders. The Janus C requires a stronger weak link, so we use 5/8 ind dia for that. We also use 5/8 inch for auto tow. We could use 5/8 for aero tow, but it does not stand up very well to the abuse.

Does any glider truly *require* a stronger rope? PTT should never be an emergency situation.

Gliding New Zealand specifies a 750 kgf weak link for all gliders, but I think all clubs I've flown at use a rope of the correct strength without any weak link. The rope gets replaced when it looks worn. I've seen a few old ropes break at initial towplane acceleration but breaks in mid air are very rare.

http://gliding.co.nz/sites/gliding.c...s/AC3-02v5.pdf

On Wednesday, April 6, 2016 at 6:39:33 AM UTC-4, wrote:
I should have added, we also install a "Whiffle" ball (lots of holes) on the glider end to protect the tow ring and also have a short length of clear plastic tubing (couple of feet more or less) that covers the poly rope. This clear tubing slides easily on the rope so it can be inspected.

Tom

Tom,

Is there an ideal location of the whiffle ball? When I saw your comment I got to thinking if there is an ideal distance from the tow ring. Our club has one on out tow rope but I have not measured the location of it.

I was speaking to someone a few weeks ago about tow ropes and they also use plastic tubing in the loop splice. But after cutting the tubing they melt the sharp edges to round them over with a soldering iron to prevent the tubing from chaffing the line.

Speaking of weak links: I was given some glider gear from a friend that her father passed away last year. In the stuff was a home made weak link. I tossed it away, but it was a length of poly with clear plastic tubing over it and fishing line weaved through it several times. I guess the fishing line test was known and the number of weaves made the strength of the weak link. I'm sure he had tested the break strength of them before using. And I'm sure he made those way before anything commercial was available. Anyone ever seen or heard of a weak link like that?