Microwave Landing System Impact on Runway Capacity

The microwave landing system (MLS) is scheduled to replace the existing instrument landing system as precision guidance for instrument operation by the turn of this century. This paper focuses on the impact of MLS on runway capacity. The advantage of MLS in this regard falls mainly on the more precise guidance and broader coverage possible. Capacity gains achievable for single‐runway, dual‐lane, and intersecting‐runway configurations using the multiple horizontal approach paths and variable glide slope capabilities of MLS are analyzed. The analysis considered mixed operations (i.e., both arrivals and departures) for a wide variety of aircraft mixes. With multiple horizontal approach paths, an increase of 5–8% in capacity can be expected for all runway configurations. With the use of different glide paths, capacity gains range from 4–12% for single and two‐intersecting runway configurations, to 10–35% for dual‐lane configurations, depending on minimum vertical separation requirement and angle of descent.