Brief introduction of instrument landing system

Instrument landing system is an international standard system for aircraft approach and landing guidance. It is an international standard landing equipment confirmed by ICAO in 1947 after World War II. Instrument landing systems all over the world have adopted the technical performance requirements of ICAO (International Civil Aviation Organization), so any aircraft equipped with ILS can get unified technical services at any airport equipped with ILS equipment in the world.

The word "blind landing" is a bit strange even for people who often fly. It's an aviation term that ordinary passengers can't touch. Literally, it doesn't mean "landing with eyes closed" or "landing blindly". Blind descent is the common name of ILS. In low visibility weather, after the ground navigation station is associated with airborne facilities, the system can aim at the runway and then land automatically. Different from the "visual approach" in normal weather, this method relies on the instrument landing system to guide the aircraft to approach and land, which can be understood as "naked eye" or "blind landing".

The instrument landing system usually consists of a VHF heading beacon, an UHF glide beacon and several VHF beacons. The heading beacon gives a heading plane aligned with the center line of the runway, and the glide beacon gives a glide plane with an elevation of 2.5-3.5. The intersection of these two planes is the accurate route given by the instrument landing system for aircraft approaching and landing. The pointer provides the key calibration points along the approach route, that is, the height check at a certain distance from the runway entrance and the distance from the entrance. During the period from the establishment of the blind landing to the final landing, if the aircraft falls below the glide line provided by the blind landing, the blind landing system will give an alarm.