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• Inspect the release assembly to ensure it has remained completely closed. 

• If the release assembly has opened, even partially, restrict the tow plane from towing duties and repair the tow assembly. 

## Tow Ring Inspection 

Tow ring inspection should begin with checking for wear and tear. The rings should not be used if they have deep scratches or dents. Like the tow hitch assembly, there are two types of tow rings: Schweizer and Tost. [Figure 12-5] The Schweizer tow ring is two inches in diameter and made of high grade, one-quarter inch steel that has been magnafluxed with good weld. The Tost tow ring is also made of high grade steel and available through most glider supply companies. 

<img src='content_image/580522.jpg'>

Always ensure that the tow line is configured for the proper type of hitch being used. For example, a Schweizer tow ring will not fit into a Tost tow hitch, but a Tost tow ring can be placed on a Schweizer type tow hitch (with the great possiblility that the Tost tow ring will become stuck in the hitch mechanism making tow rope release impossible). 

## Tow Rope Inspection 

Although the pilot of the glider is primarily responsible for the selection and inspection of the proper tow line, it is also the duty of the tow pilot to confirm that the tow line selected meets the requirements of the Federal Aviation Administration (FAA) Regulations and is acceptable for use.  [Figure 12-6] The tow line should be inspected as follows: 

<img src='content_image/580523.jpg'>

• Check the entire length of the tow line for abrasions, security of splices, and general condition. 

• The tow line should be free from excess wear; all strands should be intact, and the line should be free from knots (knots in the tow line reduces its strength by up to 50 percent and causes a high spot in the rope that is more susceptible to wear). 

• Pay particular attention to the ring area to which the glider attaches because this is also a high-wear area. 

• Consideration should be given in replacing the tow rope after a period of time due to usage and ultraviolet (UV) exposure from being in the sun and exposed to the elements. 

• Ensure tow line strength is appropriate for the glider being towed. 

## Tow Rope Strength Requirements 

Stated in the 14 CFR part 91, section 91.309, the minimum tow rope strength is eighty percent of the gliders maximum certificated operating weight. The maximum strength is twice the maximum certificated operating weight. The maximum certificated operating weight can be found in the specific pilot ’s operating handbook (POH) for the glider and may be the maximum certificated gross weight at takeoff. Figure 12-7 shows the strength of some ropes that are typically used. If the tow rope has a breaking strength more than twice the maximum certificated operating weight of the glider being towed, a safety link (weak link) has to be installed at the point of attachment of the glider and the tow plane with the following breaking strength requirements: 

