L-3 TECHNOLOGIES ESI-500 - Direction Digital Readout; Direction Invalidity; Heading Index

ESI-500
Pilot’s Guide3-10
Display Features
Direction Invalidity
If congured for heading, the direction tape and readout is removed
from the display and replaced with a heading failure message “HDG”
when invalid heading data or excessive magnetic eld dip is detected.
See Chapter 4 for details.
If congured for track, the direction tape and readout is removed from
the display and replaced with a track failure message ‘TRK’ when the
computed track data is invalid or depending on the GPS source, the
track failure message may be shown when the aircraft is not moving,
or moving slowly. See Chapter 4 for details.
Heading Index
The heading index is a xed downward pointing arrowhead located
at the top-center of the heading tape. The heading index points to the
current heading shown on the heading tape and provides the value
shown in the heading readout.
Direction Digital Readout
The Direction readout is located above the direction tape. The tape
has a range of 001° to 360° with a resolution of 1°.
When track is congured, the readout digits are preceded with the
direction source indicator ‘TRK’.
The readout is removed whenever the menu window is opened.