TIPS FOR MAKING A TOWLINE
by Len Buffinton
LET Minimoa on Tow, Ribbon is easily visable
You can’t tow a sailplane if you don‘t have a towline. When setting up your towline, you need to consider what you will be towing. The bigger the sailplane, the bigger the towline will need to be.
Within reason:
A towline is your lifeline to the sky, its also you lifeline is something goes wrong. You hope the line never breaks during tow, unless something bad happens which puts you into a horrible situation, and then you pray it does.
How do you control what breaks?
The towline should never break. Period. The tow loop, which is the part you slip into the nose of the sailplane and secures to the release, should break when something goes haywire. That loop is the weak link.
Lets back up a bit
When getting your sailplane ready to fly, after bolting on the wings, taping the joints and polishing the canopy, you should attach a tow loop to the nose release in the sailplane. This exercise is mandatory when attending any aerotow event. It takes time to get he loop in and positioned correctly. You do NOT want to be doing that at the last minute. There are guys waiting in line behind you to fly, and I bet they have their tow loops in. Nobody wants to watch you struggle to get a loop in while the tug sits there idling.
Once you pull the plane out onto the field, you simply hook the fishing swivel attached to the end of the towline to your loop and off you go. No waiting, no rush, no pressure. It is very typical to have tow loops provided when attending a well-organized event. Most tow masters will have a traffic cone setting near the flight line. This cone is where the assistant places all the tow loops as they come off the swivel from the previous launch. These loops will vary in size, but will be considerably weaker than the actual towline.
(Mason line makes a great loop for 20+ lb sailplanes)
What size should the towline be?
If you are towing with a small tug, 30cc and under, you will tow sailplanes no heavier than around 18lbs. This size plane can be towed with Mason Line. This brightly colored line is available at any lumberyard or hardware store.
The length of the towline can be shorter for smaller sailplanes, about 70 feet for 18lb and under.
When the sailplanes get larger, the towline needs to be stronger and longer, between 100-120 feet for planes over 18 lbs. Length will vary, depending on personal taste.
After having a towline break at low altitude, while flying a 41lb ASW 28, I decided that day to change the all my towlines to heavy braided twine.
Braided Twine, excellent towline material
This product is purchased from Memphis Net and twine supply. http://www.memphisnet.net/category/twine_greenbraidedseine It’s very strong and durable. When towing from our club field, which is located in the middle of a cornfield, just about every landing by the tug is made dragging the line through the cornstalks. Occasionally, the line will wrap around a stalk just right and make for an interesting landing. Usually, the stalk gets ripped out of the ground, except once; when the tug came to a complete STOP about 6 feet off the ground. Quick thinking and throttle response saved the plane, AND, the towline was ok. In this instance, it would have paid to have a weak link at the tug end of the towline too.
Regardless of which line you are towing with, you need to have a flag or streamer on the end toward the sailplane. The flag should be brightly colored and big.
Surveyor Flagging Tape
I prefer a long (10-12 ft) nylon ribbon on the end. The ribbon can be scene from the ground and lets you know what the line, and subsequently, your sailplane is doing. If you see the ribbon bowing, you are catching up to the tug. You might want to consider putting out the spoilers for a few seconds., watch the line tighten, then continue on your way. When attaching the ribbon, be sure to place it far enough up the line that it will not snap against the sailplane. Leave some room between the ribbon and the nose of the sailplane. The visual aid device can be made from nylon, cloth, or even plastic surveyors’ tape as shown here.
The swivel, which is attached to the sailplane end of the towline, is nothing more than a good quality, heavy duty fishing swivel with a clip. Depending on the size of the towline you’re using, will determine the size of the swivel.
Heavy duty fishing swivel
You’ve had another great day of towing, now you need to pack up your towline; it’s best to wrap it around a spool or a wooden block. Simply coiling it up is a bad idea. The next time you want to use it you will have a coil of knots, complete with a ribbon and swivel.
Words to the wise
Make up more than one towline. During the coarse of our aero-towing fun, somewhere, sometime, somehow, the towline will get release from the tug. I’ve lost at least 4 towlines due to ME hitting the release on the tug when I was towing. There is something about that little switch that makes me want to flip it when the sailplane pilot says he’s releasing. Once this happens, finding these towlines is next to impossible, and you really don’t want to spend a nice day searching for a $6.00 towline.
I carry 4 ready-made lines in my trailer plus a spool of line and extra swivels in the event of a really bad day. Having all the parts needed to put together a towline when needed has saved my day more than once.
Be prepared, like dad always said.
