What type of landing system is classified as a precision approach?

The correct choice relates to the Microwave Landing System (MLS), which is classified as a precision approach system. A precision approach system provides accurate lateral and vertical guidance to aircraft during landing, ensuring that pilots have the necessary information to execute landings in various weather conditions. MLS utilizes microwave signals to provide precise guidance to aircraft, which enhances safety and allows for approaches in reduced visibility.

This classification is important for understanding different landing aids and their capabilities. Other systems, such as NDB (Non-Directional Beacon), SDF (Simplified Directional Facility), and ASR (Airport Surveillance Radar), serve different roles in navigation and approach but do not provide the same level of accuracy and guidance necessary to be classified as precision approach systems. These alternatives are typically used for more general navigation rather than precise landing guidance.