For the Departure/Destination/Alternate Aerodrome block on an 1801, insert _____ if the LOCID contains a number, no LOCID assigned, or not known

For the Departure/Destination/Alternate Aerodrome block on an 1801, insert _____ if the LOCID contains a number, no LOCID assigned, or not known

• A. ZZZZ
• B. UNKN
• C. NONE
• D. XXXX

Answer: (A)

In this field you must provide a four-character LOCID for the departure/destination/alternate aerodrome. When there is no valid localizer ID, or the LOCID is not assigned or not known (and it may be numeric or otherwise unusable), you use ZZZZ. This placeholder is the standard signal to flight plan processing that the localizer ID isn’t available, so the data stays consistent and unambiguous for automation and ATC systems. Other options like UNKN, NONE, or XXXX aren’t the official placeholder for this situation in the 1801 LOCID field, so they aren’t used to indicate “not available” here.

In this field you must provide a four-character LOCID for the departure/destination/alternate aerodrome. When there is no valid localizer ID, or the LOCID is not assigned or not known (and it may be numeric or otherwise unusable), you use ZZZZ. This placeholder is the standard signal to flight plan processing that the localizer ID isn’t available, so the data stays consistent and unambiguous for automation and ATC systems. Other options like UNKN, NONE, or XXXX aren’t the official placeholder for this situation in the 1801 LOCID field, so they aren’t used to indicate “not available” here.