vertically. Though utilized already in some areas, it has not been fully implemented
throughout the National Airspace System.
Monitoring Navigation Aids
The most refined NAVAIDs are of little value when they are not working. Only when the
NAVAIDs are in the air and functioning properly can you and the pilot make use of their
data. It is essential that you know the status of NAVAID equipment at all times.
Each facility that is delegated monitoring responsibility is required to continuously
monitor a NAVAID that is required or desired to remain on the air. This authority may be
delegated to any on-station agency provided (1) there is continuous manning, (2)
automatic visual and aural alarms are installed, (3) maintenance personnel are readily
available in the event of a malfunction, and (4) NOTAM responsibilities can be met.
When these conditions cannot be met, the periods of operation must be published in the
appropriate FLIP products, and the NAVAID must be monitored during those periods.
Whenever the NAVAID cannot be monitored, it must be put in a non-radiating status or
the identification feature must be removed.
During flight operations, a NAVAID's operational status must be continuously monitored.
Sometimes the equipment used to monitor the NAVAID's status is located at a site
different from its actual location (i.e., in a RADAR room or control tower cab). When the
NAVAID's monitor equipment at a remote site malfunctions and the NAVAID cannot be
monitored from the remote site, personnel must be sent to the NAVAID's actual site.
These personnel monitor the NAVAID's status until the conclusion of flight operations.
When a NAVAID is monitored at the site, you must ensure that the monitoring
equipment is operating properly and that reliable two-way communications are available
between the site and the primary facility.