Autozenith
The unbridled Yagu uses small bike lights on the rear pigtails to induce autozenith when flying single line. Yagu SLE uses a pair of Danish 5kr coins to serve the same function. The Danish mint thinks that small denomination coins should double as kite stabilizers and conveniently include a hole in the center. I attach one coin to each rear tip inside the kite.
"Can you really bribe a kite into stability?" I hear you ponder. You bet! In fact kites to prefer "hard currency" and won't respond to paper money, no matter how large the denomination. Here's how it works:
The drawing above is a kite pilot view, where the LE is facing you. The kite is leaning over to its left side, but the LE is still facing the wind flow.
When Yagu moves towards one side of the window, the weight at the rear wingtips cause them to sag. This sag means a change in tip AOA and net lift generated in the opposite direction. The force involved is proportional to displacement to each side of the window.
The exact same lean + gravity autozenith effect is present in other kite styles as well. E.g. a classic Eddy kite is zenith seeking because the bridle center is in front of the weight center.
Peter Lynn has a more in depth look at kite stability in his January 2009 newsletter.
