B737 Navigation Control Panel

Active (ACT) Mode and Frequency Indicator

• Indicates the active mode and frequency.

Transfer Switch

• Push – standby mode and frequency moved to active indicator window; active mode and frequency moved to standby indicator window.

Standby (STBY) Mode and Frequency Indicator

• Indicates the standby mode and frequency.

TEST Switch

• With a VOR frequency tuned and a course of 000 selected:
  • shows VOR fail flag
  • deviation bar biases out of view and then returns to centered position
  • bearing pointer slews to 180 degrees
  • DME displays:
    • DME fail flag
    • dashes
    • normal DME distance.
• With an ILS frequency tuned and a course within 90 degrees of airplane heading:
  • pointers disappear and LOC and G/S flags appear momentarily
  • pointers appear and display one dot up and one dot left
  • pointers then display one dot low and one dot right
  • pointers then return to normal display
  • DME displays:
    • DME fail flag
    • dashes
    • normal DME distance.
• With a GLS frequency tuned and a course within 90 degrees of airplane heading:
  • pointers disappear and LOC and G/S flags appear momentarily
  • pointers appear and display one dot up and one dot left
  • pointers then display one dot low and one dot right
  • pointers then return to normal display.
  • Note: DME is not tested with GLS and no indications will be displayed.

Mode Switches

• Push – manually insert ILS, VOR, or GLS into the standby indicator window.

Frequency Selection Keypad

• Push – manually selects the standby frequency.
• CLR – clears the standby frequency.