When using a vehicle to tow a glider, use a towline that is  more than half the wingspan of the glider. If one wingtip  stops moving for any reason, this towline length prevents  the glider from pivoting and striking the tow vehicle with  the opposite wingtip. Full wingspan length is desirable;  however, half the wingspan plus 10 feet provides safe  operation. Ensure that the glider canopy is always closed  if no one is around the glider. This prevents the wind, or  turbulence from a taxiing towplane, to cause the canopy to  close abruptly, which could damage the canopy frame or  even crack the canopy glass. If it is necessary to move the glider during high winds, use  two or more crewmembers placed at the wingtips and tail.  Also, have a pilot in the cockpit, with the spoilers deployed,  holding the controls appropriately to reduce lift on the glider.  Strong winds and gusts can cause damage to the glider during  ground handling, so exercise care during these conditions. Another method of towing uses specially designed towing  gear similar to a trailer tow bar that attaches directly to a  vehicle towing a trailer. The tow bar makes guiding the glider  much easier and allows the wing walkers to concentrate on  ensuring wingtip clearances.  [Figure 6-7] When starting, slowly take up slack in the line with the  vehicle to prevent sudden jerking of the glider. The towing  speed should be no faster than a brisk walk. When towing a  glider, always use at least one wing walker. The wing walker  and the driver of the tow vehicle function as a team, alert  for obstacles, wind, and any other factor that may affect the  safety of the glider. The driver should always stay alert for  any signals from the wing walkers.  [Figure 6-6] Prior to making a flight, it is important to inspect the condition  of the towline/towrope. The glider pilot is primarily responsible  for inspection and selection of the proper towrope. However,  the tow pilot has a responsibility to ensure that the towrope  selection meets the criteria stated in 14 CFR part 91 and is  acceptable for use. This inspection is the responsibility of  the tow pilot. The towline should be free from excess wear;  all strands should be intact, and the line should be free from  knots. Towropes should be inspected prior to every flight.  Consideration should be given in replacing the towrope after a  period of time due to usage and ultraviolet (UV) exposure from  being in the sun and exposed to the elements.  [Figure 6-8]  14  CFR part 91, section 91.309, requires that the strength of the  towline be within a range of 80 to 200 percent of the maximum  certificated weight of the glider. If the towrope is more than  twice the maximum strength, a safety link is required between  the tow rope and glider rated at not less than 80 percent of  the maximum certified operating weight of the glider but not  greater than twice the operating weight. Also, a safety link  must be installed between the towing aircraft and towrope  with breaking strength greater than the glider safety link, but  no more than 25 percent greater, and not greater than twice the  maximum certificated weight of the glider.  Figure 6-9  shows  the strength of some ropes typically used.  Launch Equipment Inspection Figure 6-6.  Positioning the glider for the tow vehicle. Figure 6-7.  A wing dolly (left) ready for attachment and a tail dolly (right) being used for glider transport. 6-5