Central to the pilot's instrument panel is a pair display screens arranged vertically. The upper display, referred to as the Vertical Display Indicator (VDI), is a multi-function screen of sorts with two primary roles. The first task is to provide navigation and flight data during normal flight and recovery. When lining up to land aboard the carrier, the VDI displays the Instrument Landing System (ILS). Made up of a set of vertical and horizontal lines, they form a perfect cross when the aircraft has achieved optimal orientation for landing. Any deviation from the "glide slope" by the aircraft results in a corresponding deviation of the ILS indicators. The ILS forms just a part of the landing aids available to the pilot, some of which will be discussed further on. During intercepts, images from the TCS are displayed on the VDI, providing a means for the pilot to identify the target while maintaining many miles of separation.
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