Keel-fixed versus keel free: Spectrum 144: self-sustaining yaw-roll oscillations
Normal glider configuration (keel able to move along cross bar)Hang glider Launched Without Buckling into Harness - a hang gliding film by Greg Porter
Impressive video - made a mistake lives to tell about it, and learned from it - and better yet helping others learn from it. The check list is king! don't get complacent