Garmin aera 660 aera 660 Pilot s Guide - Page 168

Overview Navigation Additional Features Hazard Avoidance Flight Planning Appendix F TIS-A LIMITATIONS TIS-A relies on surveillance of the Mode-S radar system, which is a "secondary surveillance" radar system similar to that used by ATCRBS. Many limitations are inherent in secondary radar surveillance. Information provided by TIS-A is neither better nor more accurate than the information used by ATC. TIS-A is intended only to assist in visual acquisition of other aircraft in visual meteorological conditions (VMC). While TIS-A is a useful aid for visual traffic avoidance, system limitations must be considered to ensure proper use. No recommended avoidance maneuvers are given, nor authorized, as a direct result of a TIS-A intruder display or TIS-A advisory. • TIS-A operation may be intermittent during turns or other maneuvering. • TIS-A is dependent on two-way, line-of-sight communications between the aircraft and the Mode-S radar antenna. Whenever the structure of the aircraft comes between the transponder antenna and the ground-based radar antenna, the signal may be temporarily interrupted. NOTE: Refer to the TIS-A Limitations section of the Aeronautical Information Manual (AIM) for a more comprehensive explanation of limitations and anomalies associated with TIS-A. NOTE: TIS-A is unavailable at low altitudes in many areas of the United States. This is often the case in mountainous regions. NOTE: Garmin is not responsible for Mode S geographical coverage. Operation of the ground stations is the responsibility of the FAA. Refer to the AIM for a Terminal Mode S radar site map. Appendices Index 152 Garmin aera 660 Pilot's Guide 190-02017-20 Rev. A