Auto-Activation of Approach NAV Frequencies
The primary NAV frequency is auto-tuned upon loading a VOR or ILS/Localizer approach.
When an ILS/LOC approach has been activated in FMS Mode, the system switches to NAV Mode as the final approach course is intercepted (within 15 nm of the FAF). Refer to the Approaches discussion in the Flight Management Section for more details.
In some circumstances the system may auto-tune a course for an unintended localizer facility because that facility shares the same frequency and is nearby the intended localizer facility. Always verify auto-tuned courses and frequencies with FAA published data and manually correct if required.
NAV frequencies are automatically loaded into the NAV Frequency Box on approach activation. When loading or activating a VOR or ILS/LOC approach, the approach frequency is automatically transferred to a NAV frequency field as follows:
|
If the Current CDI NAV Source is NAV1 or NAV2 |
If the Current NAV Source is FMS |
|
|---|---|---|
|
Approach LOADED |
Approach frequency is transferred to the standby frequency field of the current CDI NAV source and to the active frequency field of the non-selected CDI Nav source. |
The approach frequency is transferred to the NAV1 and NAV2 active frequency fields and the previously active frequencies are transferred to standby. If the approach frequency was already in the NAV1 or NAV2 standby frequency field, the standby frequency is transferred to active. |
|
Approach ACTIVATED |
Approach frequency is transferred to the active frequency field on both NAV1 and NAV2 and the previously active frequencies are transferred to standby. |