Systems and methods for advising a flight crew member that an enhanced ground proximity warning system (EGPWS), for example, may continue to provide terrain alerts, cautions, warnings, or the like because an intended landing site for the aircraft is not recognized within a database of airports. An unknown airport advisory is generated and broadcast after the aircraft is in a landing configuration, when the aircraft is greater than a threshold distance from the nearest landing site in the database, but before the terrain alerts are broadcast. The pilot may actuate a "terrain inhibit" selection device after receiving the advisory. The inhibit device may deactivate or mute subsequent alerts generated by the EGPWS during that particular landing sequence.