How To Make a Tow Line
How long should the towline be?
It depends on the size and weight of your sailplane...but even less than ideal lengths can be made to work (so don't get overly stressed about this).
We have experimented with a lot of tow planes and sailplanes and came up with this guide.
Small foam sailplanes, like the Multiplex Easy Glider, which are 2M or less wingspan and about 2lbs. in weight...#18 braided nylon mason line about 60-65' long works very well. The twisted mason line will also work, but the braided line is more durable and easier to work with.
Slightly larger foam sailplanes, like the Multiplex Cularis, which are about 2.5M in span and about 3lbs. in weight...#18 braided nylon mason line about 75' works very well.
The small scale sailplanes in the 2.5-3.0M wing span are tricky to tow for reasons other than the towline length, but, #18 braided nylon mason line about 75-85' works okay.
Scale sailplanes in the 3.0-3.8M wing span are a little easier to tow successfully...and #18-21 braided nylon seine twine about 85-90' long works very well.
Scale sailplanes in the 4.0-6.0M wing span are much easier to tow...#24-30 braided nylon seine twine about 100' long is great.
Scale sailplanes in the 6.0-7.0M wing span range works well with #30-36 braided nylon seine twine about 100-110' long is fine,
Finally, scale sailplanes in the 8.0M+ wing span range work well with #36 braided nylon seine twine about 110-120' long is fine.
These are not absolutes, just the sizes that we have used with good success.
What Is the line made of?
A good source of heavier duty nylon seine twine is the Memphis Net & Twine Co., Inc.
We have found that the #30 size is a good all around size for our typical aero tow events where most sailplanes are in the 4-8M range. The #24 size has also worked well, especially if there are smaller sailplanes in the mix.
How does it attach to the tow plane?
A simple overhand knot works fine for the tow plane attachment and for the swivel attachment, although you may want a "cooler" looking knot "just because!"
How does it attach to the sailplane?
It is very helpful to have a quick way to connect the line to the sailplane tow release, a snap link is perfect for this. As for the snap link, Memphis Net & Twine sells the Rosco terminal tackle line of products and after some experimentation the Rosco Swivel with Snap size #2/0 has worked the best for us.
