While engaged in the APP mode:
- The A autopilot and Captain’s F/D use information from the
Captain’s Course Selector and No. 1 VHF NAV receiver.
- The B autopilot and First Officer’s F/D use information from
the First Officer’s Course Selector and No. 2 VHF NAV
receiver.
- Different courses and/or frequencies for the two VHF NAV
receivers can cause disagreement between Captain’s and
First Officer’s F/D displays and affect A/P operation.
Option - CWS deactivated on approach
After localizer and glideslope capture, CWS cannot be engaged by
manually overriding pitch and roll. Manual override of the autopilots
causes autopilot disengagement.