| HORIZONTAL SITUATION INDICATOR ( HSI ) |
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DESCRIPTION
The HSI is located in the pilot instrument panel. This indicator is used in conjunction with the Direction Finder Set, VHF/FM Radio operating in the homing mode, Gyro magnetic Compass Set, the VOR-LOC-GS-MB System which supplies landing approach information and Doppler NAV for range, bearing, course information. Part of the information to the HSI is controlled by the HSI Display Control Panel located in the pilot instrument panel. |
| CONTROL / INDICATOR | FUNCTION |
| 1. Heading marker | Enables pilot, by adjusting HDG SEL knob, to set the marker to a desired heading reference. |
| 2. Course pointer | Indicates selected course. |
| 3. TO indicator | Indicates selected course is in the direction, within plus or minus 90 degrees, of the course to the station. |
| 4. Bearing pointer number 1 | Indicates bearing relative to a ground station ( ADF-VOR ), as determined by the HSI Display Control Panel. |
| 5. COURSE indicator | Provides selected course readout ( in degrees ) to indicate course pointer. |
| 6. NAV warning flag | Indicates loss of radio navigational signal. |
| 7. GS flag | Indicates loss or unreliable glideslope radio signal. |
| 8. Glideslope deviation pointer | Indicates aircraft position relative to glideslope centerline. |
| 9. FROM pointer | Indicates selected course is within plus or minus 90 degrees to the course from the station. |
| 10. CRS SEL knob | Manually adjusts, course pointer and COURSE readout, to set desired course or track for VOR and LOC. |
| 11. Azimuth indicator | Indicates aircraft heading. |
| 12. Aircraft symbol | Provides immediate indication of azimuth relative to desired course and course deviation. |
| 13. Course deviation bar | Indicates aircraft deviation from desired VOR, LOC or FM course or track. |
| 14. HDG SEL knob | Manually adjusts to select desired aircraft heading. |
| 15. HGD flag (warning) | Indicates loss of instrument power or directional gyro information is invalid. |
| 16. Bearing pointer number 2 | Indicates bearing relative to a ground radio station ( ADF-VOR ) as determined by HSI Display Control Panel. |
| (M) 17. RANGE readout | Indicates range to destination. |
