The difference between hub and non-hub airports – An airside capacity perspective

Abstract Airport airside capacity is limited by the runway system capacity or apron capacity, whichever is more constraining. Sometimes, taxiway system can also impose constraint to airside capacity, but in the case of fully developed taxiway systems (involving parallel taxiway, high speed exits, etc.) that is usually not an issue. To determine which airside element is more constraining it is not always as simple as comparing runway system and apron capacities directly one to another. It is important to understand and take into consideration their relationship. Runway-apron relationship depends on demand characteristics e.g. dominant market segments (e.g. scheduled, charter, low-cost, general aviation, cargo), and/or specific traffic patterns (hubbing or point-to-point services, seasonality in demand, etc.). The paper brings up the issue of available airside capacity under different traffic characteristics, faced by hubs vs. non-hub airports, and the necessity to understand runway-apron interdependency in order to properly identify the bottleneck on the airside. Referring to earlier findings related to apron capacity analysis, the paper summarizes various factors that affect apron capacity at non-hub and hub airports and uses them to define the runway-apron relationship, as well as its role in the process of analyzing airside capacity under various demand characteristics. The main finding is that functional relationship between the runway system and aprons is much stronger in the case of hub airports, and should be carefully considered when analyzing airside capacity. Besides runway capacity, few other variables that affect apron capacity at hub airports are discussed. Generic examples are used to support the discussion.