What factors influence the selection of a runway for arrival or departure?

Several factors influence the selection of a runway for arrival or departure, with the primary considerations being wind direction and velocity, runway length and condition, aircraft performance characteristics, noise abatement procedures, and air traffic control efficiency. Wind direction and velocity are paramount. Aircraft typically take off and land into the wind (headwind), as this provides increased lift and reduces ground speed, shortening the takeoff or landing distance required. Runways are numbered based on their magnetic heading; for instance, runway 27 has a magnetic heading of approximately 270 degrees. Ideally, the runway most closely aligned with the prevailing wind direction will be selected. Runway length and condition are also crucial. Longer runways are necessary for larger, heavier aircraft, or those operating at higher altitudes or temperatures, which reduce aircraft performance. The runway surface condition (dry, wet, snow-covered, or icy) also affects braking action and takeoff performance. Aircraft performance characteristics play a significant role. Different aircraft have different takeoff and landing distance requirements, climb gradients, and approach speeds. Air traffic controllers must consider these factors when assigning runways to ensure that aircraft can safely operate within the available runway length. Noise abatement procedures are often implemented to minimize the impact of aircraft noise on surrounding communities. These procedures may dictate the preferred runway for arrivals and departures during certain times of day or under specific wind conditions. Air traffic control efficiency is also a factor. Controllers aim to select runways that optimize traffic flow, minimize delays, and reduce controller workload. This may involve using multiple runways simultaneously or assigning runways based on the direction of flight. For example, if the wind is calm or nearly calm, a 'calm wind runway' might be designated for use. Therefore, a balanced assessment of these factors is essential for selecting the most appropriate runway for each arrival and departure, ensuring safe and efficient air traffic operations.