AIM ¶ 1-1-11 — NAVAID Identifier Removal
AIM 1-1-11 explains why FAA NAVAID identifiers are removed during maintenance and the T-E-S-T code. Study guide for pilot students prepping for checkrides.
When an FAA NAVAID is taken offline for routine or emergency maintenance, technicians remove the coded Morse identifier (and voice, where applicable). The missing ident is your warning that the facility is officially off the air and any signals you receive — even strong, steady ones — may be unreliable for navigation.
Key points to remember:
- No ident = don't use it. Even if your CDI centers and the needle behaves, the signal cannot be trusted.
- VHF ranges (VORs) may broadcast a T-E-S-T code during maintenance: dash, dot-dot-dot, dash ( - ● ●●● - ). Hearing T-E-S-T means the station is in test mode, not in service.
- NOTAMs override the ident. If a NAVAID is NOTAMed out of service, do not fly the procedure even if you hear a normal identifier — during testing the regular ident may briefly be transmitted.
Operationally, this means part of every NAVAID-based procedure is checking NOTAMs in preflight planning and positively identifying the station by ident before tracking it. This is why instructors hammer "tune, identify, monitor" — skipping the ident check on a maintenance NAVAID can lead you off course on an approach or airway.
Five FAA-written-style questions. Instant explanations, every answer cites its source — no account needed.
You are flying VFR in Class E airspace at 8,500 feet MSL during the day. What are your minimum visibility and cloud clearance requirements?