What does capacity refer to in the context of airspace?

Capacity in the context of airspace is fundamentally about the capability to manage a volume of traffic over a specified time. This includes the ability of air traffic control systems, procedures, and the physical airspace itself to support a certain number of aircraft operating safely and efficiently within that space at any given moment.

It takes into consideration factors such as the complexity of air traffic routes, the efficiency of air traffic management, the weather conditions, and the capabilities of air traffic control technology. Thus, understanding capacity is crucial for optimizing the flow of air traffic, enhancing safety, and minimizing delays.

While the ability of an airport to handle aircraft landing pertains to its operational aspects, it does not encompass the broader concept of airspace capacity, which is more aligned with the overall management of air traffic within the designated airspace. Similarly, the number of airports in a region or the maximum number of aircraft that can be in the air at once do not accurately define airspace capacity, as they either reflect geographic distribution or absolute numbers without considering the dynamic nature of air traffic management.