Marine Corps Cpl. Samuel Kulenek and other students prepare to be extracted by a CH-53E Super Stallion helicopter during a SPIE-lining exercise at Schofield Barracks, Hawaii, Oct. 19, 2017. Patrol personnel, each wearing a harness with an attached carabiner, hook up to a D-ring inserted in the SPIE rope. A second safety line is attached to a second D-ring located above the first. The helicopter lifts vertically from an extract zone until the rope and personnel are clear of obstructions, then proceeds in forward flight to a secure area. Marine Corps photo by Lance Cpl. Luke Kuennen