HORIZONTAL SITUATION INDICATOR (HSI)

Heading display on the HSI has 3 selectable modes: Full compass, Arc, and Map mode.
Modes are selected by pushing the HSI button.

Displayed on initialization.
360-degree compass view
Present heading is indicated by a fixed lubber line at the top of the heading scale with a digital heading readout directly above the lubber line.

90 degrees of compass view.
Weather is displayed when the WX button is pushed.
When the heading bug goes beyond the display range is displayed and shows the shortest direction to the heading select bug.

Displays the digital value for the aircraft selected heading.
Cyan heading select bug is positioned by rotating the HDG SEL knob.
Pushing the PUSH SYNC button on the HDG SEL knob synchronizes the heading bug and readout to the current aircraft heading.
When the aircraft selected heading (or the referenced aircraft heading) is invalid, the bug is removed, and digital readout is replaced with

Represented by an inverted solid white triangle displayed on the outside edge of the heading scale.
The difference between the aircraft heading and the aircraft ground track is the drift angle.
The drift angle bug is placed on the edge of the heading scale and aligned to the drift angle with respect to the lubber line.
When the drift angle is 0 degrees, the drift bug fits inside the heading bracket notch.

Selected using the V/L or FMS buttons.
The V/L(VOR/LOC) button selects the available SRN (short-range navigation) source, displayed in green.
- The associated annunciators are
The FMSbutton selects FMS as the source, displayed in magenta.
- With dual FMS systems installed the identifier will show
When both sides have the same NAV source selected, digital readout for all information turns amber.

Green for VOR and LOC navigation and the label is
- When VOR or LOC is selected, the track pointer is positioned by turning the CRS knob.
- When the PUSH DIR button in the center of the CRS knob is pushed, the course select value is set to the course that minimizes the lateral deviation.
Magenta for FMS navigation and the label is
- Value of the desired track is supplied by the FMS.
Course deviation bar moves laterally and shows lateral deviation.
If both sides have the same navigation source selected the pointer, deviation bar, and digital readout turn amber.

Magenta for FMS, Green for VOR or LOC. Turns amber if both sides are selected to the same source.
Pointer indicates the aircraft is flying to or away from the selected navigation source.
For a TO indication the triangle is located above the nose of the aircraft symbol.
The FROM indication is a triangle pointer on the tail of the aircraft symbol.

Only displayed when a navigation source is active.
Deviation bar moves left or right to show the deviation from the selected NAV source.
When the back course mode is selected, or when tuned to a localizer frequency and the selected course is more than 100 degrees from the aircraft heading, the course deviation automatically reverses to properly sense deviation with respect to the course centerline.
When lateral deviation data is invalid, the CDI is removed and is displayed in the CDI scale area.

DME source is selected by pushing the V/L button.
DME source annunciation reflects the short-range navigation source selection.
- VOR1/LOC1 displays VOR2/LOC2 displays
When primary NAV source is FMS, the last selected VOR/LOC is used for the DME distance display.
When the same source is used, the DME data is displayed in amber.

DME source station identifier is displayed directly below the DME source annunciator.
Distance to go to the waypoint identified by the DME station identifier is shown in nautical miles.
TTG to the waypoint identified by the DME station identifier is shown in minutes.
When DME is in DME hold mode is displayed in the front of the distance readout.

Last updated 10 months ago