Which system provides lateral and vertical guidance?

• A. Instrument Landing System
• B. Global Positioning System
• C. VOR
• D. ADS-B

Answer: (A)

The capability to provide both left-right and up-down guidance during an instrument approach comes from the Instrument Landing System. It has two main components that work together to keep the aircraft on a precise path to the runway: the localizer, which gives horizontal (lateral) guidance to align the aircraft with the runway centerline, and the glide slope, which provides vertical guidance to follow a descent path to the runway. This combination makes it a precision approach, allowing the aircraft to fly both the correct course and the correct altitude as it nears the runway.

VOR offers only lateral guidance (bearing to a station), ADS-B provides surveillance information about aircraft positions, and GPS (by itself) is a position/navigation tool rather than a dedicated system that continuously guides both lateral and vertical descent to a runway.