Airport capacity is defined by the maximum number of aircraft movements (take-offs and landings) and passengers a facility can handle within a specific timeframe, and it is governed by several rigid constraints. The primary bottleneck is often runway throughput, which is limited by wake turbulence separation standards; a smaller plane cannot land immediately after a heavy jet because of the dangerous air vortices left behind. Physical infrastructure also plays a massive role; the number of available boarding gates, the size of taxiways, and the efficiency of the terminal's baggage handling and security checkpoints create "chokepoints." Furthermore, environmental and regulatory constraints are increasingly significant in 2026. Many airports operate under strict noise abatement protocols that forbid flights during late-night "curfew" hours or limit the total number of annual slots to appease local communities. Finally, air traffic control (ATC) staffing and the complexity of the surrounding airspace—especially in crowded regions like London or New York—limit how many planes can be safely managed in the sky simultaneously.