Aviation Speak

This expression is used by air traffic controllers to warn pilots that their aircraft are no longer being picked up by radar and therefore the pilots are not receiving radar services. You may hear the term "radar contact lost" when contact has been lost completely or when the signal has become unreliable. The reasons that air traffic controllers lose radar contact with an aircraft are varied. Among the potential causes are the aircraft entering an area of weather or ground clutter, the aircraft dropping below radar line-of-sight coverage, failure of the aircraft's transponder, the aircraft entering an area of poor radar reception, or failure of the ground radar unit. If you have been using flight following services, expect the words "radar contact lost" to be followed by an advisory that radar services have been terminated and in- structions to squawk VFR (1200) on the transponder.

Terminal Area Charts

These VFR charts exist specifically to provide pilots with more detailed information in Class B and surrounding airspace. A terminal chart uses a scale of one-to-250,000 compared to a scale of one-to-500,000 for a sectional chart and one-to-1 million for a world aeronautical chart. The smaller scale allows chart makers to provide more topographic details like landmarks that can help pilots to navigate through VFR corridors and other special-use airspace in the vicinity of Class B airspace. In addition, these charts contain radio frequencies, controlled airspace, restricted areas, obstructions, and other related data. For safety's sake, pilots are urged to use terminal charts in addition to the standard sectional charts any time they are transiting an area for which a terminal chart is published. Sectional charts indicate which areas are covered by terminal charts.