1–1–11 NAVAID Identifier Removal During Maintenance
During periods of routine or emergency maintenance, coded identification (or code and voice, where applicable) is removed from certain FAA NAVAIDs. Removal of identification serves as a warning to pilots that the facility is officially off the air for tune-up or repair and may be unreliable even though intermittent or constant signals are received.
Note: During periods of maintenance VHF ranges may radiate a T-E-S-T code ( – • • • • – ).
Note: DO NOT attempt to fly a procedure that is NOTAMed out of service even if the identification is present. In certain cases, the identification may be transmitted for short periods as part of the testing.