You turn your body up hill off the lip of the pipe, rotating against your momentum.
Alley-Oop Flat Spin 540
Take off straight out of the pipe. Drop your uphill shoulder down the fall line and rotate horizontally with your hips or back facing the ground. Your tips basically do a loop toward the fall line.
You can land backwards after 360, or keep going with the 540, dropping your tips into the transition.
