except the aircraft symbol, attitude, and attitude sensor
annunciation are removed from the ADI. Refer to
Figure 3C-7. All ADI information is restored when at
of pitch or
of roll. If the PFD is
displayed when an extreme attitude condition occurs,
the excessive attitude ADI page automatically is
displayed. Refer to Figure 3C-8. The PFD is not
selectable until the extreme attitude condition is
removed and then it must be reselected.
(5) Flight Director Command Bar Display.
The command bars are in view when the flight director
is being used. The command bars are removed from
view by the flight director when it is turned off, in
standby mode, commanded out of view, and FD
The integrated command bars flank the
triangular aircraft symbol with a zero command input.
The command bars move a maximum of
The command bars are removed from the
display and the flight director annunciation appears
when the commanded pitch or roll is invalid. The flight
director annunciation consists of the label FD in black
on a solid red box.
c. Flight Director Annunciations. The Flight
Director (FD) annunciations are displayed in the
Lateral Arm, Lateral Capture, Vertical Capture, Vertical
Arm 1, and Vertical Arm 2 annunciator fields. The
capture annunciations are green and the arm
annunciations are white. To ensure that the flight crew
does not miss a FD change, the FD annunciation
flashes for 5 seconds when a new annunciation
occurs. Refer to Table 3C-4 for FD output and their
The MFD displays red-colored dashes in the FD
fields and retains the FD command bars if the FD sets
more than one annunciation for that field or if the Data
Concentrator Unit fails. The annunciator fields will be
blanked when the command bars are removed from
the display, when the unit is turned off, placed in
standby mode, commanded out of view, or FD validity
d. Vertical Guidance. The FDS-255 supports
glideslope and VNAV Guidance. The glideslope scale
and pointer are displayed when the navigation source
is LOC, the localizer is valid, and the glideslope is
valid. The VNAV scale and pointer will be displayed
when the navigation course source is FMS, the FMS is
valid, the VNAV is valid, and the VNAV is available
from the FMS.
A scale and pointer located on the right side of
the indicator displays deviation from the selected
vertical path. The scale consists of a pair of white dots
above and below a white center index. Maximum
travel of the pointer is 2.5 dots.
The glideslope (GS) deviation pointer is a
magenta trapezoid outlined in white. If a glideslope
failure is detected, the letters GS appear boxed and in
red. The GS pointer and scale will be removed from
the display. The GS pointer moves a maximum of
± 2.5 dots.
The VNAV deviation pointer is a magenta star
outlined in white. When a VNAV failure is detected the
VNAV annunciation appears boxed and in red. The
VNAV pointer and scale will be removed. The pointer
moves a maximum of ± 2.5 dots.
e. Lateral Deviation. The pointer and scale are
located on the bottom center of the ADI. The pointer
moves a maximum of
2.5 dots. The scale consists
of two white dots on either side of a white center index.
The lateral deviation pointer is a white rectangle
with two magenta bars for VOR, or non-approach FMS
navigation sources. The rising runway serves as the
lateral deviation pointer for LOC, BC, and approach
FMS course sources. Back course deviation is
reversed on the ADI when the B/C is set via the flight
director control panel.
If the navigation source is invalid or missing, the
course source annunciation is boxed in red and the
pointer, rising runway (LOC, BC, or FMS approach),
and lateral deviation scale are removed from the
The FMS Navigation warning indicates that the
information accuracy is in question but usable. The
FMS navigation solution remains displayed but the
color changes to amber.