Military Special Operation Unit Rappelling Course T-Shirt. Digitally Printed on soft superior 100% ring-spun Cotton, Triblend, 50/50 premium Soft Style Quality T-shirts. Not Slim Fit Size XXL is Heavy Cotton. Rappelling is used as a tactical measure to penetrate a room or area by non-conventional means. The U.S. Army Air Assault School is a 10 day course that qualifies soldiers to conduct airmobile and air assault helicopter operations this includes aircraft orientation, slingload operations, proper rappelling techniques and fast-rope techniques. The design consist of two special operators tactically appraching an enemy combatant.