Risk When the Rope Doesn't Break

Gliding safety begins before you take off. Proper Preparation on the ground is essential to prevent emergencies before they happen. One risk to address before the start of your flight is related to the tow rope, specifically the potential danger it poses, NOT breaking. The solution to this issue lies in a simple but vital component: the TOST weak link.

What is a Weak Link?

A weak link is a safety feature installed at the attachment point between the towline and the glider. Also, between the towline and the towplane. Its purpose is straightforward: It’s designed to break when the towline is under too much tension for the aircraft. This is particularly important when the tow rope is rated too strong for your glider. You might be asking, “How can a tow rope be too strong for a glider? Isn’t it better for the rope to be strong so it doesn’t break?” We obviously don’t want a weak tow rope that will break, but if a tow rope is too strong, it could cause damage to your glider or the tow plane.

Consider this: if there is slack in the towline that suddenly tightens, the tension could exceed what the glider or tow plane can safely handle. This excessive stress could lead to damage. That's where the weak link comes in. This safety mechanism acts as a buffer between the towline and your glider, ensuring that if the rope experiences excessive tension, it will break before any damage occurs.

Protective Sleeve

While the weak link solves the issues an overly strong tow rope might create, using it unprotected carries risk. Because of this, TOST offers several additions for the weak link to prevent abrasion and premature wear. While technically, you can use just the standalone weak link, TOST recommends pairing it with a protective sleeve. The sleeve helps shield the weak link from unnecessary wear and tear, which, in the worst-case scenario, could lead to an unplanned release. A prematurely broken weak link is an emergency in itself. It is very important to be aware of this issue because when your weak link is worn down to the point where it is deformed, the breaking strength can no longer be defined.

The protective sleeve is a great way to prolong the life of your weak link and prevent an unplanned release, but you can improve safety further by adding a reserve system to your weak link assembly.

The Reserve System

The reserve system is a backup when the primary weak link fails due to wear. If the primary weak link breaks prematurely, the reserve system takes over by catching the tow rope and keeps the glider attached to the tow plane. The reserve weak link can be identified by its oval-shaped holes, unlike the round holes of the primary weak link.

When a reserve weak link is paired with a primary weak link, the breaking strength remains unchanged because the reserve weak link only comes into play if the primary weak link has failed. This ensures that the overall breaking strength remains predictable and safe. However, not mixing up the reserve and primary weak links is important. Using two primary weak links together would double the breaking strength, which could put your glider at greater risk in the event of excessive tension on the tow rope.

Choosing your weak link system

With all these different options available. The question is: which addition should you use on your weak link? These various additions exist to offer increased safety by mitigating the risks associated with using a weak link. The safest choice is to use the full assembly, which includes the protective sleeve and the reserve system. Combining these two components creates a more reliable and fail-safe mechanism for your glider.

When it comes to glider safety, we should always aim to take every precaution necessary to minimize risks during flight. The added protection offered by the full weak link assembly significantly reduces the chances of an emergency while in the air. When prioritizing safety, we want to take every precaution to minimize the risk of emergency while in the air, so there is no reason we shouldn’t use the complete assembly.

While focusing on one small but critical part of the gliding experience, this topic highlights the broader principle of flying safely. Properly installing and maintaining a TOST weak link assembly is an easy and effective way to enhance towing safety. Taking the time to set up the weak link properly reduces the likelihood of emergencies during flight, protecting both the glider and the pilot.
In the end, safety should always be our top priority. Whether you are a seasoned glider pilot or a student, understanding and using the proper safety mechanisms like the TOST weak link will help ensure that your time in the air is as safe and enjoyable as possible.

Banner photo by Sean Franke

  Adam Franke has been immersed in aviation and gliders for as long as he can remember. On his 14th birthday, he completed his first solo flight, marking his place as a fourth-generation glider pilot in his family. Growing up, Adam gained invaluable experience by flying frequently and serving as ground crew during competitions, where he developed an understanding of competitive soaring. He now holds a private glider license and recently participated in his first SSA competition as a backseat pilot. In his current role at Wings & Wheels, Adam is dedicated to supporting pilots and growing the soaring community, helping to foster a thriving future for the sport