TM 55-1510-215-10
1.
DME readout display
2.
Lubber line
3.
Compass flag
4.
Course pointer
5.
Rotating heading dial
6.
To-From pointer
7.
VOR/ADF switch
8.
Heading knob
9.
Heading bug
10.
Course knob
11.
Symbolic aircraft
12.
Glideslope deviation pointer/scale
13.
Course deviation bar and scale
14.
NAV flag
15.
Photocell
16.
Bearing pointer
AP011855
Figure 3-8. Pilot's Horizontal Situation Indicator
the heading bug will maintain its position. The difference
selected. Switching to HOLD will store the channeling
between the bug and the fore lubber line represents the
information from the NAV frequency selector which was
heading select error applied to the flight director
previously selected. No frequency selector thereafter
computer.
affects the DME, and any frequency selector may then
be set to another frequency. The DME will remain on
(j) Compass .flag. When the compass
the frequency being stored until NAV 1 or NAV 2 is
flag is in view, compass information is not valid.
selected. 1H or H2 on the display indicates a HOLD
setting, as well as the NAV frequency selector whose
(k) Course deviation bar and scale.
setting was held.
The yellow course deviation bar represents the
(f) RNV display.
The indicator will
centerline of the selected VOR, RNAV, or localizer
course. This deviation is depicted as either linear or
display RNV when the displayed distance, groundspeed,
angular deflection of the course deviation bar.
and time-to-station are derived from the area navigation
system. This RNV legend will flash when HOLD mode
Angular deviation is displayed in the VOR or TACAN
has been selected. The display is blanked when RNV is
modes. One dot deflection in the VOR or TACAN mode
flashing.
equals 2-degree off course, whereas full scale or 5 dots
(g) Photocell.
The
photocell
equals 10-degrees off course.
When a localizer
automatically controls readout brightness with respect to
frequency is selected. one dot deflection equals 1/2-
degree deviation, whereas full scale or 5 dots equals 2
cockpit ambient lighting.
1/2-degree deviation off course.
(h) Lubber line. Fixed heading mark.
Linear deflection is displayed in the VOR RNV, VOR
(i) Heading bug. The orange heading
RNV APR, TACAN RNV and TACAN RNV APR modes.
When using linear deflection, (excluding APR mode) one
bug is positioned on the rotating heading dial, by the
dot deflection equals one nautical mile off course and
heading knob, to select and display a preselected
five dots equal five nautical miles off course. This
compass heading. Once set to the desired heading,
Change 5 3-15