In a Microwave Landing System, which components are typically included?

• A. Azimuth station, elevation station, and precision distance measuring equipment
• B. Localizer, glide slope, and marker beacons
• C. VOR, DME, and SSR
• D. GPS, WAAS, and MLS

Answer: (A)

Microwave Landing System delivers precise three‑dimensional approach guidance by using two scanning beams plus a distance measuring capability. The azimuth station emits sweeping beams to determine the aircraft’s position left or right of the runway centerline, providing horizontal guidance. The elevation station uses its own scanning beams to establish the vertical position, supplying the glide-path information. The precision distance measuring equipment gives accurate range to the runway, completing the distance information needed for a safe touchdown. Together, these three elements form the MLS guidance for an approach.

Other systems are not MLS: the localizer and glide slope are parts of the ILS, along with marker beacons. VOR, DME, and SSR are different navigation and surveillance aids, not MLS components. GPS and WAAS relate to satellite navigation and are separate from MLS guidance.