U.S. Army divers of the 569th Engineer Dive Detachment, located in Fort Eustis, Va., jump into the Arkansas River from a CH-47 Chinook helicopter while helocast training during River Assault 2011 at Fort Chaffee, Ark., July 26. Helocasting is a method of inserting small units and their equipment by helicopter onto the water. River Assault culminated with the construction of a floating improved ribbon bridge across the Arkansas River.