What is the primary concern when activating Critical Area Signs?

The primary concern when activating Critical Area Signs is to protect ISL (Instrument Landing System) Critical Areas. These areas are designated to ensure the integrity of the navigation aids that support aircraft operations, particularly during instrument approaches and landings. When aircraft are in landing or takeoff mode, it is crucial to maintain a clear and unobstructed area around the Instrument Landing System to prevent any interference that could jeopardize safe aircraft operations.

ISL Critical Areas are specifically sensitive to any potential disruptions, which is why certain measures are put in place to ensure that vehicles and personnel do not enter these areas when they could interfere with operations. This is essential for maintaining a safe airside environment, particularly under conditions where precise navigation is required for aircraft approaching the runway.

While protecting taxiway areas, maintaining runway clearances, and controlling vehicle access points are important aspects of overall airport operations, they do not address the specific needs and sensitivities associated with ISL Critical Areas, which is the primary focus when these signs are activated.