¡ï Nationality Sign of Civil Aircraft
Every country in the world has its sign of nationality for civil aircrafts (airplane is one of them). By relevant international regulations, ¡°B¡± was chosen as the nationality sign of civil aircrafts of China in 1974. All civil airplanes of China are marked with the sign ¡°B¡± and serial numbers for the convenience of wireless connection, air traffic control in navigation, and telecommunication, especially for the convenience of identification and call in air crash. Therefore, it would be a mistake if you take the B in the ¡°B-2820¡± on the airplane of China Southwest Airlines which has the eagle as its symbol as Boeing.
¡ï What are the major types of airplanes in the world?
Airplanes manufacturers mainly include the Boeing Commercial Aircraft Company, the Europe's Airbus Consortium and the McDonnell Douglas of U.S.A. At the end of 1996, the Boeing Company merged with the McDonnell Douglas. The Boeing series mainly include: Boeing 707£¬Boeing 727£¬Boeing 737£¬Boeing 747£¬Boeing 757£¬Boeing 767 and Boeing 777. The Airbus series mainly include: A-300¡¢A-310¡¢A-320¡¢A-330¡¢A-340. And the McDonnell Douglas series mainly include: MD-80¡¢MD-81¡¢MD-82¡¢MD-83¡¢MD-87¡¢MD-88¡¢MD-11. In addition, there are airplanes manufactured by Russia: TU-154 and TU-154M and those manufactured by former Soviet Union: Il-18, Il-86, Jacques-42 and An-30. Other airplanes include the BAE-146 and Short -360 made by Britain, Fokker-100 made by Dutch, as well as Yun-7, Yun-8, Yun-10, Yun-11, and Yun-12 made by China. China Southwest Airlines now has 42 comfortable and safe planes with advanced performances, mainly including Airbus 340-300, Boeing 757, and Boeing 737. The 20 Boeing 737 planes owned by the airline now is the biggest Boeing 737 air fleet in all China¡¯s civil airlines.
¡ï Why do planes sometimes need to wait at the juncture of taxiway and runway for a while?
There are two reasons. One is that the control tower of airport commands that the planes entering the hub should land first or directs that the planes should take off in turn. The other reason is weather. Sometimes bad weather will last for a short time above the airport, therefore planes need to wait until the weather turns good and orders are given by the control tower.
¡ï Traffic regulations for planes in the air
There goes a saying that birds can fly as freely as they wish in the air. Can planes also fly freely in the boundless sky? The answer however is ¡°no¡±. In fact, airplanes should observe the air traffic regulations strictly. Different flying height has been stipulated by the aviation control department for different airplanes. Small airplanes generally fly at the height under 3000 meters while middle and large size airplanes generally fly at the height above 3000 meters. Airplanes need to fly in fixed air routes of 8-20 miles wide. Every air route is divided into different levels; the height between two adjoining levels shall be within 600 meters. Besides, when facing, crossing or passing by each other, the vertical intervals between two planes shall be no less than 600 meters to ensure safe and smooth air traffic.
¡ï Why do airplanes sometimes circle over airport before landing?
There are three reasons. Firstly, the airplane is adjusting directions toward the runway and ready to land along the slide slope stipulated by the air traffic control center. Secondly, when the airplane is queuing in turn in the air according to the command of the aviation control center as there are too many landing airplanes occupying the slide slope and the routes, the airplane can not but circle in the air. Thirdly, if poor visibility is caused by bad weather, the airplane can not but wait by circling until the order to land is given.
¡ï What is black box? And what are the functions of it?
Black box, which is not unfamiliar to people, is a kind of electronic recording equipment specially designed for airplanes with its real name being flight recorder. Equipped with flight data recorder and Cockpit Voice Recorder, it is connected to all sensors of the mechanical parts and electronic instruments and meters of the airplanes, just like the brain is connected to the nerves of body parts. It can record all relevant technical parameters and cockpit voices half an hour before the airplane¡¯s break down or crash. When needed, all parameters recorded can be replayed for flying experiments or accident analysis. The black box has strong ability to resist fire, pressure, shock and vibration, sea water (or gasoline) soak as well as electromagnetic interference. Therefore, even if the airplane has been damaged, the black box still keeps well the data it has recorded. As all the causes of air crashes in the world are found out by black boxes, they become the witness of accidents enabling people to draw lessons from mistakes and to take better safety measures to prevent the happening of similar accidents. |
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