What are the four ground-based components of the Instrument Landing System (ILS)?

The four ground-based components of the Instrument Landing System (ILS) are essential for providing precise navigation guidance for aircraft approaching a runway. These components consist of the localizer, glide slope, marker beacons, and approach lights.

The localizer provides horizontal guidance by transmitting a signal that indicates the centerline of the runway. The glide slope offers vertical guidance, informing pilots of the proper descent angle to maintain during approach. Marker beacons serve to give pilots distance information as they navigate toward the runway, typically marking specific points along the final approach path. Lastly, approach lights enhance visibility of the runway environment, especially during low visibility conditions.

The correct understanding of these components is crucial as they play significant roles in facilitating safe and precise landings, especially under instrument meteorological conditions (IMC) where visual cues are limited. Recognizing the correct components enhances knowledge about ILS operations and contributes to safer aviation practices.