Beechcraft C-12C Operator And Technical Reference Manual page 305

3B-14. COPILOT'S
INDICATOR.
a. Description.
Situation Indicator (HSI) combines numerous displays
to provide a presentation of the aircraft position. The
indicator displays aircraft displacement relative to
VOR, localizer, glideslope beam, and heading with
respect to magnetic north. Any warning flag in view
indicates that portion of the HSI display is unreliable.
Display brightness is adjusted with a rheostat,
placarded HSI, located on the copilot's instrument
panel.
b. Controls/Indicators and Function. Refer
to Figure 3B-7.
(1) Digital Distance Display (DIST). Provides
digital display of station distance.
(2) Rotating
Displays gyro stabilized magnetic compass information
on a dial that rotates with the aircraft throughout 360°.
The azimuth ring is graduated in 5° increments.
1. Digital DIST Display
2. Rotating Heading Dial
3. Lubber Line Mark
4. Digital COURSE Display
5. Azimuth Marks
6. Course Pointer
7. To-From Pointer
8. Compass Synchronization Annunciator
HORIZONTAL SITUATION
The copilot's Horizontal
Heading (Azimuth)
Figure 3B-7. Copilot's Horizontal Situation Indicator (HSI)
(3) Lubber Line.
located at the fore (upper) and aft (lower) position.
(4) COURSE Display.
readout of selected magnetic course.
(5) Azimuth Marks.
(6) Course Pointer.
pointer is positioned on the heading dial by the course
knob to select a magnetic bearing that coincides with
the desired VOR radial or localizer course.
course pointer rotates with the heading dial to provide
a continuous readout of course error to the computer.
When either one of the radio modes is selected, the
vertical command bar on the Attitude Flight Director
will display bank commands to intercept and maintain
the selected radio course.
(7) To-From Pointer. The to-from pointers,
aligned on the course pointer, are located 180° apart.
Dial.
One always points in the direction of the station, along
the selected VOR radial.
9. Course Knob
10. Course Deviation Dots
11. Aircraft Symbol
12. Heading Knob
13. Glideslope Pointer and Scale
14. Course Deviation Bar
15. Heading Bug
TM 1-1510-218-10
Fixed heading marks
Provides a digital
The yellow course
The
3B-15