Early followers of online AWE discussion will recall “Pete” Lynn (Peter Lynn’s son) in 2004 envisioned a sustained flight mode based on a kite (or kites) orbiting over a suspended payload. Pete’s theoretic flight mode has since evolved in kite sports into the standard Heli Loop, now taught by kite pros. Many other applications remain possible.
A Heli Loop flight control tutorial-
Here is a more advanced heli/mega loop tutorial with admirable analysis and nicely overlaid graphical animations-