Jim Prahl discussed with me the history of the efforts at Quest Air and Lookout Mountain for the best way to connect the pilot to the tow line. A quest that continues to this day.

The problem is that when the bridle line is released from a barrel release at one of the shoulders (or a V-bridle line is released from the keel), the line flies out and over the ring at the end of the tow rope. As it lays across the ring it can wrap around the ring and tie itself to the ring. Various measures have been taken to make sure that this doesn't happen.

First it was thought that it would be better if the ring was bigger. So they put on bigger rings and found that it was in fact easier to get a wrap if the ring was bigger. That the smaller the ring, the less likely the bridle was to wrap around the ring.

The explanation, as they found out, was that if the ring (or carabineer) presented less material essentially perpendicular to the tow rope, the less likely the bridle line was to snag on the ring. The small ring with the sharper radius reduced the amount of material perpendicular to the tow line.

One option the Jim and Quest used was to make a tear dropped shaped loop at the end of the toe line with an aluminum tube or plastic. The tear drop shape sheds the bridle lines when they are released. This is what Tracy and Lisa use at Cloud 9. Quest found this to be a very safe and practical tow rope end.

If you have a V-shaped carabineer with the narrow end at the tow rope end of the line then the two sides of the carabineer are less likely to cause the bridle to snag as it slides back and off these sides. Oval shaped carabineers are more likely to allow the bridle to wrap around them as they mimic the larger round rings. So the Quest Air people went looking for and started to use more V-shaped carabineers.

These types of carabineers are also more common now as the carabineer manufacturer's have shaped their bineers to put the load on the non opening side of the bineer.

Quest was using small rings at the end of their tow ropes until there became the need to very quickly attach pilots to the tow ropes at competitions. Rings required that the pilots mess with their bridles to undo them and put one end through the ring. This is both a safety issue and an issue of getting everyone off quickly.

Quest now uses very inexpensive light non locking aluminum carabineers, the kind that often are used on key chains. These are much cheaper and lighter than the ones I linked to in the first article about Bernie's accident. Carabineers like this. Notice the shape. Quest Air personnel pick them up by the handful at ACE hardware. They are on both ends of the tow rope. As soon as they get worn, they are replaced.

The cheap aluminum carabineers that Quest Air now uses with its spectra bridle systems with barrel releases have been used successfully with thousands of tows without incident.

Jim discussed with me the bridles that he made from hollow spectra. He said that one doesn't want to have a build up of a bump on the spectra material where it is spliced (see the HGFA accident report linked to earlier). What he did to avoid this is splice the spectra line all the way back to the splice on the non released side. This meant that there was no "bump" where the splice ended where it went through the carabineer, as that part of the bridle never went through the carabineer.

I sell a bridle made from very thin Spectra or Vectran. Jim prefers the thicker Spectra, thinking that it is less likely to wrap around the ring. Our experience with the thin Vectran or Spectra is that it has not wrapped around the carabineer or ring.

Again, I have a direct personal and minor financial interest in the issues raised by this discussion.