*Please do not attempt to aerotow any glider without first receiving instruction from a qualified aerotow instructor.*
The list below will give you a good starting point for attaching an upper aerotow release to our current production gliders. There are a number of other factors that may cause you to want to move it slightly forward or aft of the starting point.
Release point
The primary factors that determine where the tow point needs to be are: the tow speed of the tug, the glider’s aspect ratio, the pitch bar pressure at tow speeds, the glider’s top speed, trim speed and the pilot’s weight. The proper placement of the tow point will trim the glider with light but positive pitch pressure while under tow.
VG Setting
All Wills Wing gliders equipped with VG are easiest to tow with the VG set to 1/2. This reduces the glider’s pitch bar pressure, while at the same time damping the roll response to reduce the chance of oscillations on tow. Pilots at the light end of the recommended weight range may want to set the VG at 1/3 on.
Vertical Stabilizers
All gliders are easier to tow when a vertical stabilizer is added to the rear keel. This provides significantly better directional stability and vastly reduces the chance of oscillations.
Tow Bridles and Releases
These tow point positions assume the use of two spliced Spectra ropes to attach to the tow line. One is attached to a shoulder tow point on the harness with a weak link, and then is routed through a spliced loop in a second longer Spectra rope, and attached to the other shoulder via a back-up release. The longer rope is then routed through the tow ring and attached to the upper release with a proper weak link. The assumed tow speed is 32 miles per hour. Some trikes tow at significantly higher speeds. The higher the tow speed, the further forward the top release must be positioned to trim away pitch pressure. Under no circumstances should you attempt to aerotow behind a tug which has a tow speed that is near the steady state maximum top speed of your glider! We do not recommend releasing from the bottom release point on your shoulders when using a V-bridle. If the bridle or weak link gets caught on the tow rope ring after releasing at the shoulders, and the glider is being pulled only from the top point, it may become unstable in pitch on tow. Use the bottom back up release only if you have a top release failure.
Towing from only the shoulder attachments without a top release is generally referred to as “Pro tow”. The Sport 2, U2s and Talons may be “Pro towed” without a top release, however this method is not as easy as using a two point release as described above. Towing without a top release will cause the base tube to be positioned much further back during tow , the glider will have increased pitch pressure, and lockouts are much more difficult to correct.
We find that the easiest way to secure the top release to the keel is to use a piece of spectra or perlon line. Start by making a loop around the keel and secure it with an overhand knot and safety half hitch in the desired location. Tie the other end of the line around the king post base secured with a bowline knot and safety half hitch, making sure that the forward loop will position the top release in the desired location.
Use a rapid link to attach the top release webbing to the line. This will make it easy to remove the release.
Always use an appropriate weak link with a finished length of 1.5 inches or less. Longer weak links are more likely to get tangled on the tow ring upon release. Carry a hook knife when towing.
MODEL TOP RELEASE LOCATION
Falcon 140, 170, 195 – On keel, just below cross bar
Falcon 225 – On keel, 3 inches in front of cross bar
Falcon Tandem – On keel, just behind the rear of the front keel pocket
Eagle 145, 164, 180 – On keel, 14 inches forward of back of bottom surface zipper (Must leave bottom surface unzipped 14 inches)
Sport 2 135, 155 – On keel, at back of bottom surface zipper – Set VG to 1/2
U2 145, 160 – On pilot’s hang loop or carabiner – Set VG to 1/2
Talon 140, 150, 160 – On pilot’s hang loop or carabiner – Set VG to 1/2
Note: The higher the top tow point the better. If the glider is equipped with a DHV (longer than Wills Wing standard length by 8 inches) it is better to tie the release to the keel rather than attach it to the hang loop.