U.S. soldiers of the 1st Battalion, 9th Cavalry Regiment stand on the skids, prepared to jump as a UH-1D Huey helicopter approaches a landing zone during Operation Thayer II in Binh Dinh province, 300 miles northeast of Saigon, in December 1966. Members of the 32-man reconnaissance company would jump as the helicopter hovered at low altitude so that the chopper didn't spend time on the ground in an unsecure area.