viIT Operation Plan Planning Directive 3-56 was the primary planning guide for Operation PLUMBBOB activities until 1 April 1957, when the 950th Test Group (Nuclear) published Operation Plan 1-57, This plan described the Air Support Group-- the 950th's forward echelon at Indian Springs--as having an operational headquarters and two major operational units. The two operational units were the Test Aircraft Unit andthe 935th Air Base Squadron, which operated Indian Springs Air Force Base, A third operational unit was provided by the 900th Air Base Group at Kirtland, This latter unit provided courier and shuttle service between Kirtland and Indian Springs. The Planning Directive gave the Test Aircraft Unit responsibility for test operational flying activities, particularly (1) test crew briefing, (2) control of sampler and cloud tracker aircraft, (3) weather reconnaissance flights, (4) radiological and providing some maintenance facilities at Indian Springs, and (5) coordinating takeoff and landing schedules, The 935th Air Base Squadron, commanded by MajorHarry EB. Elmendorf, was responsible for (1) housing, messing, and some administrative and logistic support for aircraft and crews staging from Indian Springs Air Force Base, (2) security and controls and identification procedures for Indian Springs, (3) operation of a dispatching office, refueling facilities, and crash fire fighting in the Nevada Test Site area, and (5) operating an airlift between Indian Springs and the Yucca Lake airstrip. Operation Plan also outlined Operation PLUMBBOB procedures and policies for personnel and administration functions, operations (including aircraft participation, flying safety, and support aircraft procedures), air,control, commnications, 16h SWEH-2-003), 19?