simultaneous ILS/MLS approaches

simultaneous ILS/MLS approaches

An approach system permitting simultaneous ILS/MLS (instrument landing system/microwave landing system) or ILS and MLS approaches to airports having parallel runways separated by at least 4300 ft between their centerlines. These are of two types: simultaneous parallel ILS/MLS approaches and simultaneous close parallel (independent) ILS precision runway monitor (PRM) approaches. In simultaneous parallel ILS approaches, the final monitor controllers are required to ensure that the NTZ (no-transgression zone) is not entered, staggered radar separation is not utilized, and pilots know they must advise ATC (air traffic control) if the simultaneous parallel approach is not acceptable. Approach charts indicate where simultaneous approaches are permitted. In independent simultaneous close parallel ILS PRM approaches, the final monitor controllers are required to ensure that no aircraft will enter the NTZ. In this case, a PRM is mandatory. There are also specific requirements in addition to those for simultaneous parallel procedures.