What are the two main vertical divisions of the Controlled Flight Area (CDA)?

The two main vertical divisions of the Controlled Flight Area (CDA) are indeed high-level airspace and low-level airspace. High-level airspace generally refers to airspace above a certain altitude, usually where aircraft operate under Instrument Flight Rules (IFR), characterized by a structured approach to air traffic management. Conversely, low-level airspace is typically below that altitude and often accommodates both IFR and VFR (Visual Flight Rules) flights, where aircraft operate with less stringent control measures.

Understanding the distinction between these two categories is crucial for pilots, air traffic controllers, and aviation professionals, as it directly influences traffic management, safety protocols, and operational procedures within controlled airspace. The division helps ensure effective separation of air traffic and enhances safety in a system that includes a variety of flight types and operational requirements.