Radar Contact
Lost
Used by ATC to
inform a pilot that radar data used to determine the aircraft's
position is no longer being received, or is no longer reliable and
radar service is no longer being provided. The loss may be
attributed to several factors including the aircraft merging with
weather or ground clutter, the aircraft operating below radar line
of sight coverage, the aircraft entering an area of poor radar
return, failure of the aircraft transponder, or failure of the
ground radar equipment.