The main differences between 4C Airport and 4D Airport are as follows:
Airport flight zone grade
The performance of the runway and corresponding facilities determines what level of aircraft can use this airport. Airports are classified according to this ability, which is called flight zone level.
The flight zone level is represented by a two-part code. The first part is a number, which indicates the runway performance and obstacle limit corresponding to the aircraft performance. The second part is letters, indicating the width of runway and taxiway required by the size of the aircraft.
Therefore, for the runway, the first number of the height layer of the flight area indicates the required flight field length, and the second letter indicates the maximum span and the maximum track width of the corresponding aircraft. Their corresponding data are shown in the following table: the first number and the second letter.
figure
Flight field length
believe
Span tread
1 less than 800 meters, less than 5 meters and less than 4.5 meters
2 800 m to 1200 m 5 m to 24 m 4.5 m to 6 m
31200m to1800m C 24 to 36m, 6m to 9m.
41800m above D 36 to 52m 9m to14m.
E 52 to 60m, 9m to 14m.
At present, the flight zones of most open airports in China are above 4D, and the flight zones of Gao Qi in Xiamen, Changle in Fuzhou, Beijing Capital, Taoxian in Shenyang, Zhoushuizi in Dalian, Hongqiao in Shanghai, Pudong in Shanghai, Lukou in Nanjing, Xiaoshan in Hangzhou, Baiyun in Guangzhou, Baoan in Shenzhen, Tianhe in Wuhan, Phoenix in Sanya, Jiangbei in Chongqing, Shuangliu in Chengdu, Wujiaba in Kunming, Gongga in Lhasa, Xianyang in Xi 'an and Diwobao in Urumqi are currently graded.
Runway basic parameters
We often hear news reports about the runway number of an airport, but don't think that it has many runways, and don't think that it is numbered sequentially or randomly. In fact, it has rules.
Direction and runway number:
The direction of the main runway is generally consistent with the local main wind direction. According to the magnetic direction of the runway center line, the runway number is 10 degrees. Four houses and five people are represented by two digits. Take Taipei Taoyuan Zhongzheng Airport as an example. Runway No.23 with magnetic field direction of 233 degrees, runway No.05 with large letters at the entrance and exit of the runway, and runway No.05 with magnetic field direction of 53 degrees at the other end of the runway. So a runway has two numbers in two directions, and the magnetic difference is 180 degrees. Runway number difference 18.
In addition, if the airport has two parallel runways, use the left and right to distinguish them. For example, the numbers of Chiang Kai-shek Airport in Taoyuan, Taipei are 5L and 5L and 5R (5 left and 5 right) respectively. If there are three, add the letter c to the middle runway number;
In order to prevent misunderstanding, if the airport has two or more parallel runways, you can take adjacent numbers.
Basic dimensions: refers to the length, width and slope of the runway.
The length of the runway depends on the takeoff and landing distance, altitude and temperature of the largest aircraft that can be used. High altitude, thin air, high ground temperature and reduced engine power all need to lengthen the runway.
The width of the runway depends on the wingspan of the aircraft and the tread of the main landing gear, and generally does not exceed 60 meters.
Generally speaking, the runway has no longitudinal slope, but in some cases it can have a slope below 3 degrees. When using a runway with slope, the influence on performance should be considered.
Pavement:
Runway pavement is divided into rigid and non-rigid pavement. Rigid pavement is made of concrete, which can bear the load of aircraft in a large area and has strong bearing capacity. Generally, medium-sized and above airports adopt rigid pavement. Almost all civil airport runways in China belong to this category.
The runway surface needs a certain amount of friction. Therefore, it is necessary to make a groove about 5 cm at regular intervals on the cement pavement and polish it regularly (6 ~ 8 years) to prevent the plane from slipping when water accumulates on the runway. Of course, there is a way to cover the rigid pavement with high-performance porous asphalt with high friction coefficient, which can not only reduce the vibration when the plane lands, but also ensure a certain friction. A few airports recently built and expanded in China, such as Xiamen Airport and Shanghai Pudong Airport, are this type of runway.
Non-rigid pavement, including lawn, gravel, asphalt and other pavements, can only resist compression but not bending, so its bearing capacity is small, and it can only be used in airports where small and medium-sized aircraft take off and land.
Intensity:
In order to accurately express the relationship between tire pressure on the ground and runway strength, ICAO stipulates that aircraft classification number (ACN) and pavement classification number (PCN) should be used to determine whether this type of aircraft can take off and land on the designated runway.
PCN number is obtained through technical evaluation of pavement properties and bearing strength of pavement foundation, and each runway has a PCN value.
The ACN number is calculated by the aircraft manufacturer according to the actual weight of the aircraft, the internal pressure of the landing gear tire, the contact area between the tire and the ground and the wheel spacing of the main landing gear. There is only an indirect relationship between ACN number and total weight of aircraft. For example, the ACN number of B747 is 55, because the main landing gear has 16 wheels, while the ACN number of B707 is 49, and its total weight is only 2/5 of that of B747, but there is little difference between the two ACN numbers.
When calculated by this method, when the ACN value is less than the PCN value, the aircraft can use this runway indefinitely. In some special cases, when the ACN value is more than 5% and less than 10% of the PCN value, the runway can be used, but it will shorten the service life of the runway.
Runway auxiliary area:
Runway shoulder: there is an isolation section between the longitudinal side of the runway and the adjacent land, so that when the aircraft deviates from the runway center line due to wind measurement, it will not cause damage. In addition, many large aircraft use wing-mounted engines, and when the aircraft is moving, the external engine may extend out of the runway. At this time, the jet of the engine will blow up the soil or sand on the ground and damage the engine. With the shoulder, such accidents will be reduced. In some airports, fire-proof blocks made of cement should be placed outside the shoulder to prevent the sprayed air from impacting the soil.
Generally, the width of the runway shoulder is 65438+ 0.5m on each side, and the pavement of the shoulder should have sufficient strength to prevent the aircraft from structural damage in the event of an accident.
Runway seat belt: the role of runway seat belt is to draw a certain area around the runway to ensure that the aircraft is in
Safety when rushing out of the runway under unexpected circumstances can be divided into side seat belts and roadside seat belts:
Side safety zone: it is an area extending outward from the center line of the runway for a certain distance. For large airports, the distance should not be less than 150m. The ground in this area should be flat and no obstacles are allowed. In case of emergency, aircraft with landing gear unable to be lowered can be allowed to make a hard landing in this area.
Roadside safety zone: refers to the area extending at least 60 meters from the runway end. The purpose of establishing a roadside safety zone is to reduce the risk of the aircraft running off the runway during take-off and landing.
Some runways also have safety stop lanes in the safety zone at the end of the runway, which is referred to as safety lanes for short. The width of the safety lane is not less than the width of the runway, but generally equal to the width of the runway. It extends from the runway end, its length depends on the needs of the airport, and its strength is enough to support the quality of the aircraft when it stops taking off.
Clearway: refers to the ground outside the runway end and the airspace extending upwards. Its width is150m, and it is symmetrically distributed on both sides of the runway center extension line. There can be no obstacles in this area except runway lights, but there is no requirement for the ground. It can be ground or water.
Taxiway:
The taxiway is used to connect the flight paths of various parts of the flight area. It starts from the apron and connects the two ends of the runway. In the middle of the busy runway, one or more runway exits are connected with the taxiway, so that the landing plane can leave the runway quickly. These are called connecting lanes.
The width of taxiway is determined by the track width of the largest aircraft in the airport. When the aircraft taxies on the center line of taxiway, the outer side of its main landing gear wheel is not less than1.5 ~ 4.5m from the taxiway sideline. At the corner of the taxiway, its width should be widened according to the performance of the aircraft.
The strength of taxiway should be equal to or higher than that of runway, because the running density of aircraft on taxiway is usually higher than that of runway, and the total weight and pressure of aircraft at low speed will be slightly higher than that of runway.
There is a waiting area near the interface between taxiway and runway end, and the ground is marked. This area is for the aircraft to wait for permission instructions before entering the runway. Keep a certain distance between the waiting area and the end line of the runway to prevent any part of the waiting aircraft from entering the runway, which will become a running obstacle or generate radio interference.