SGT Jeff Johnson of Headquarters and Headquarters Co., 4th Bn., 87th Inf. 25th Inf. Div. (Light) signals to a helicopter coming in for a cargo pickup during the joint Australian/U.S. exercise Kangaroo '89. One of the soldiers behind Johnson will attach the load to the helicopter's external cargo hook; the other is holding a grounded probe that will safely discharge any static electricity generated by the helicopter