Deviation Bar and Scale

The VOR deviation bar shows in magenta. The DEUs use VOR bearing from the VOR/MB receivers and course inputs from the DFCS mode control panel to calculate VOR deviation. The scale is the standard four dot scale. One dot equals five degrees of deviation.

The DEUs remove the deviation bar for NCD deviation inputs from the VOR/MB receivers.

Selected Course Pointer

The course select control on the DFCS mode control panel sets the position of the selected course pointer.

To/from Pointer and Indicator

The TO/FROM pointer is a small white triangle that shows as part of the selected course pointer. The TO/FROM pointer shows on the centered VOR display only.

The TO/FROM indicator shows at the bottom right corner of both the centered and expanded VOR displays. The DEUs use VOR bearing from the VOR/MB receivers and course inputs from the DFCS MCP to calculate TO/FROM pointer and indicator displays.

The TO indication shows when you enter a course on the DFCS MCP that takes you to the VOR station. The FROM indication shows when you enter a course that takes you away from the VOR station.

The DEUs remove the TO/FROM pointer and indicators for NCD and invalid displays.

Nav Data Source

The DEUs show the source of the data for the ND display in the upper right corner. The normal source for the captain NAV display is the VOR/MB receiver 1 and the normal source for the first officer is the VOR/MB receiver 2.

Vor Frequency

The VOR frequency shows in the upper right next to the NAV data source. The frequency from the NAV control panel goes through the VOR/MB receivers, then to the DEUs for display. The frequency shows in green. IF the VOR receiver gets a valid station identifier from the VOR station, the station identifier replaces the VOR frequency.

The DEUs change the VOR frequency to dashes for NCD inputs from the VOR/MB receivers.

VOR SYSTEM - EFIS INVALID DISPLAYS

Invalid Display

The DEUs remove these displays for invalid VOR/MB receiver inputs:

• Deviation bar and scale

• TO/FROM pointer and indicator

• VOR frequency

• NAV data source

• Bearing pointers.

The DEUs show the amber VOR flags on both the centered and expanded VOR displays for VOR/MB receiver failures.

VOR SYSTEM - FRONT PANEL BITE

Test

Push the test switch on the front panel to start a test of the VOR receiver. The test results show on the LED status indicators. There are two status LEDs. The LRU status LED can be red or green. The control fail LED is only red.

When you push the test switch, the receiver does a check of the internal receiver operation and its interface with the NAV control panel. The test takes 48 seconds. This is the test sequence that shows on the LED status indicators during the test:

• 0 to 2 seconds - the LRU status and the control fail LEDs are red

• 2 to 4 seconds - the LRU status LED is green and the control fail LED is red

• 4 to 12 seconds - the LRU status and the control fail LEDs go off

• 12 to 42 seconds - test status shows.

The LRU status LED indicator shows green for an LRU test pass condition or red for an LRU test fail condition. The control fail LED shows red if there is no tuning input from the NAV control panel or if the signal is invalid.

Test

You can do a test of the VOR/MB receivers from the flight compartment with the NAV control panels. The captain’s NAV control panel does a test of VOR/MB receiver 1 and the first officer’s NAV control panel does a test of VOR/MB receiver 2. You need to set these controls to do a test of the VOR/MB receivers:

• Enter a valid VOR frequency into the active frequency display window on the NAV control panel

• Set a selected course of 000 on the DFCS mode control panel

• Set the mode selector on the EFIS control panel to the VOR position

• Push the test switch on the NAV control panel.

This is the flight compartment display sequence that shows during the VOR test:

• Invalid display (VOR flag)

• NCD display (deviation bar out of view)

• Test display (deviation bar centered).