Instrument Landing System (ILS)
The ILS system provides both Vertical and Horizontal guidance to a specific runway. The ILS system is used to execute a precision instrument approach procedure or precision approach. Most navigation systems approved for Enroute and terminal operations under IFR, such as VOR, NDB, and GPS, may also be approved to conduct instrument approach procedures. The most common system in use in the United States is the ILS. An ILS (instrument landing system) operates as a ground-based instrument approach system, using a combination of radio signals, during IMC conditions, this system will guide airplanes to land during low ceilings or reduced visibility due to fog, rain, or blowing snow.
The system consists of the following components:
- A localizer, providing horizontal (left/right) guidance along the extended centerline of the runway.
- A glideslope (GS), providing vertical (up/down) guidance toward the runway touchdown point, usually at a 3° slope.
- Marker beacons, providing range information along the approach path.
- Approach lights assisting in the transition from instrument to visual flight.
ILS Approach Procedures
After knowing the basic ILS principles and how the system works, the pilot must demonstrate the procedures on how to fly a precision instrument approach “ILS” during his/her checkride. This course will include a complete video on how to fly an ILS approach.