TM 55-1510-221-10
(22.) Heading knob (located on the pedes-
PILOT SELECT annunciator will illumi-
tal). Positions the heading bug to a preselected head-
nate to notify the copilot that both pilots
ing.
have selected the same receiver.
(23.)
Pilot’s COURSE INDICATOR selector
switch (fig. 2-29). Selects desired source of data for
display on pilot’s HSI and input to autopilot flight
computer.
1 system.
2 system.
(a.) VOR 1. Selects data from VOR
(b.)
VOR 2. Selects data from VOR
(I.) Compass synchronization annuncia-
tor. The compass synchronization annunciator con-
sists of a dot and X symbol display. When the com-
pass system is in the slaved mode, the display will
oscillate between the dot and X symbol, indicating
the heading dial is synchronized with a gyro stabi-
lized magnetic heading.
(c.) TACAN.
Selects data from
TACAN system.
(2.)
VERT flag. Indicates that the infor-
mation displayed by the glideslope pointer is invalid
and should not be used.
(d.) INS. Selects data from INS.
c. Controls/Indicators and Functions (Copi-
lot’s HSI. fig 3-11).
(3.) Rotating heading (azimuth) dial. Dis-
plays gyro stabilized magnetic compass information
on a dial which rotates with the aircraft throughout
360 degrees. The azimuth ring is graduated in 5
degree increments.
NOTE
If both the pilot and copilot COURSE
INDICATOR select switches are in the
same position, except INS, the pilot has
sole control of course select functions.
The copilot can only monitor deviation
displays from the selected system. A
(4.)
Azimuth marks. Fixed azimuth marks
are at 45° bearings throughout 360 degrees of the
compass card for quick reference.
(5.)
Course deviation bar. The course devi-
ation bar represents the centerline of the selected
VOR, TACAN, INS or localizer course. The minia-
ture aircraft symbol pictorially shows actual aircraft
position in relation to this selected course.
Figure 3-11. Copilot’s Horizontal Situation Indicator (RD-550)
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