TCAS/ATC Transponder Control Panel

Altitude Range Switch

The Altitude Range Switch (labeled ABOVE/N/BELOW) sets the altitude range for displaying intruders (TCAS traffic) on the Navigation Displays.

All intruders are reported as a relative altitude in hundreds of feet from aircraft's current altitude. A + symbol indicates traffic is above and a - symbol indicates the intruder is below (i.e. +02, indicates traffic is 200 feet above aircraft's altitude). The ABS/REL switch is deactivated.

The altitude range settings are:

  • ABOVE selection displays relative altitude reporting traffic from 2700 feet below to 7000 feet above airplane altitude.
  • N (Normal) selection displays altitude reporting traffic from 2700 feet below to 2700 feet above airplane altitude.
  • BELOW selection displays altitude reporting traffic from 7000 feet below to 2700 feet above airplane altitude.