Blind Landing is an instrument landing system (Instrument Landing System).
Blind Landing is an instrument landing systemILS(Instrument Landing System) commonly known. Because the instrument landing system can guide the aircraft to approach and land under low weather standards or when the pilot cannot see any visual reference, the instrument landing system is called blind landing.
instrument landing system is an international standard system for aircraft approach and landing guidance.International Standard Landing Equipment as confirmed by the International Civil Aviation Organization ICAO in 1947. ICAO's technical performance requirements are adopted for instrument landing systems all over the world, so that any aircraft equipped with blind landing can receive uniform technical services at any airport equipped with blind landing equipment around the world.
instrument landing system usually consists of a VHF (VHF) localizer beacon, a UHF glideslope and several VHF marker beacons. The localizer gives the heading plane aligned with the runway centerline, and the glideslope gives the glide plane with an elevation of 2.5 °-3.5 °. The intersection of these two planes is the accurate approach and landing route given by the instrument landing system. The marker provides keyed calibration points along the approach route, I .e., altitude checks at a certain distance from the runway entrance, and distance from the entrance. During the stage of establishment blind descent and final landing, if the airplane is below the glide line provided by the blind descent, the blind descent system will give an alert.
blind descent is particularly prominent in bad weather and low visibility. It can provide a reliable approach and landing channel for the aircraft when it is difficult for the pilot to find the runway or signs with naked eyes, so that the pilot can master the position, orientation and descent altitude, so as to land safely. According to the precision of the blind landing, the blind landing provides different approach landing standards to the aircraft, so the blind landing can be dividedClass I II III standard.
The weather standard for Class I blind landing is that the visibility ahead is not less than 800 meters (half a mile) or the runway visual range is not less than 550 meters, and the decision height of the minimum landing standard is not less than 60 meters (200 feet). In other words, the Class I blind landing system can guide the aircraft on the glide path and automatically descend to a height of 60 meters from the runway elevation. If the pilot can see the runway at this altitude, he can land, otherwise he will have to go around.
Class II blind descent standard is that the visibility ahead is 400 meters (1/4 mile) or the runway visual range is not less than 350 meters, and the decision height of the minimum landing standard is not less than 30 meters (100 feet). Like Class I, the autopilot descends to a decision height of 30 meters. If the pilot visually sees the runway, he can land, otherwise he will have to go around.
Class III blind landing means that the runway cannot be effectively seen at any altitude, and the landing decision can only be made by the pilot, with no decision altitude.
Class III blind descent can be subdivided into three subcategories: ⅢA, ⅢB, ⅢC.
Class IIIA is 200 meters (700 feet) of visibility ahead, decision height less than 30 meters or no decision height, but sufficient landing suspension distance should be considered, and the runway visual range should not be less than 200 meters;
Class IIIB is that the visibility ahead is 50 meters (150 feet), the decision height is less than 15 meters or there is no decision height, the visual range of the runway is less than 200 meters but not less than 50 meters, and there is enough distance to allow sliding after grounding;
Class Ⅲ C has no decision height and no runway visual range restrictions, that is to say, under the condition of "out of reach", it can automatically drive a safe landing and taxiing by virtue of blind descent guidance. At present, ICAO has not approved Class III C operation.
