Guys, helical is helical. Regardless if the vane is 2 inches long or 5 inches long. You still get the same degree of helical with both lengths. The only differance is thatyour eye doesn't visually pick itup with the shorter vanes as it does with the longer vanes. The longer vane just makes it easier to see. Fletched helically they are just as effective as a regular vane fletched the same way.

There are three things that make them work well.

#1. The are stiffer so they resist airturbulance better than regualr vanes.

#2. The angle of rise from the base is greater so it gets more vane into the passing air and creates more drag.

#3. The vanes are taller so it gets the vaneinto less tirbulant air away from the shaft. less air tirbulance allows the vane to work more efficiently.