green. If the radio altimeter system fails, the decision
height readout is removed.
When the radio altitude is at or below the DH
setting, the yellow letters DH appear in the right center
portion of the ADI or PFD display. The DH
annunciation flashes for 10 seconds after it appears.
Once the DH annunciation appears, it will be removed
when the radio altitude climbs at least 25 feet above
the decision height setting or if the radio altitude is less
than 10 feet. If the radio altimeter system fails, the
decision height annunciator is removed and the radio
altitude flag appears.
j. Fast/Slow Deviation and Pointer. Speed
deviation indicates whether the aircraft is fast or slow
relative to an established reference. The speed
deviation scale consists of four white dots with the
letters F and S to the left of the top and bottom dots.
The scale is located on the left side of the ADI. The
speed deviation pointer is a magenta diamond outlined
in white. The scale is relative to FMS speed (FSPD)
associated with FMS 1. Whenever FMS speed is
available, the letters FSPD in white are positioned
below the scale. When selected, fast/slow input is
invalid and the source is drawn in black on a solid red
box. The speed deviation pointer is displayed in
amber when the cross-side FMS is the selected
navigational source. The pointer and scale will be
removed from the display.
k. Inclinometer Indicator. The inclinometer is
a separate element mounted under each display. The
inclinometer is a weighted ball in a liquid-filled curved
glass tube to provide assistance in making coordinated
maneuvers. Aircraft slip/skid movement is shown by
the movement of the ball.
l. Marker Beacons. The inner, middle, or outer
marker beacon annunciation is displayed on the center
left of the display when set by the marker beacon
receiver. The marker beacon annunciator will be
removed from the display when the marker beacon
signal is no longer available from the marker beacon
consists of an O in amber for the outer marker, M in
cyan for the middle marker, and I in white for the inner
m. Free Format Line. The free format line is
used to display system faults only.
n. Comparator Warning Annunciation. Each
display compares pitch attitude, heading, glideslope
deviation, localizer deviation, and radio altitude to the
cross-side (X-side) display. If the comparison exceeds
a threshold, the appropriate annunciation appears at
the top of the EADI.
o. Primary Flight Display Format. For
reversionary purposes. The Primary Flight Display
mode consists of an ADI positioned on top of an HSI
with a 360
compass rose. Refer to Figure 3C-9. The
differences in the display are listed in the following
(1) The rising runway and lateral deviation
pointer is removed from the ADI.
(2) Approximately 30
of the pitch scale is
(3) The lubber line is a solid white triangle
pointer and heading is not digitally displayed.
(4) Approximately 200
of the compass rose
is displayed. The bottom half of the compass rose is
clipped from view.
(5) No wind text label.
(6) No off the display heading readout or
pointer for the heading bug.
In extreme pitch attitudes, the presentation
reverts to the normal excessive attitude display that is
a modified full ADI display.