What is the purpose of the Minimum Crossing Altitude (MCA)?

The Minimum Crossing Altitude (MCA) is specifically designed to indicate the minimum altitude that an aircraft must maintain when crossing a particular navigational fix on a route. This altitude ensures safe vertical separation from obstacles, ensuring that aircraft can operate safely and effectively in controlled airspace. By adhering to the MCA, pilots can also comply with air traffic control requirements and maintain safe terrain clearance, particularly in rugged or densely populated areas.

In instrument flight, maintaining the MCA is critical for both safety and compliance with air traffic procedures, giving pilots a clear altitude benchmark to follow as they navigate through the airspace.