The Organization of an Airport
An airport is the location where aircraft take off and land, where goods, passengers and their baggage transit. Aircraft may be stored or maintained at an airport, where we usually distinguish two main parts: an air side and a land side. In the former we find all the infrastructures and services that serve to move aircraft, runways, taxiways, aircraft parkings, aprons and the air traffic control system; in the latter there are all the facilities and services associated with passengers such as the access to the airport, the terminal footpaths and the car parks. Gates are instead usually considered the border between the two areas.
The airport ramp or apron is the area where aircraft are parked, unloaded or loaded, refueled and boarded. The apron is not usually open to the general public and a license may be required to gain access.
The use of the apron may be controlled by the apron management service (apron control or apron advisory). The apron is designated by the LC.A.O. (International Civil Aviation Organization) as not being part of the maneuvering area. All vehicles, aircraft and people using the apron are referred to as 'apron traffic'.
In the USA, the words 'apron' and 'ramp' are used interchangeably in most circumstances. Generally, the preflight activities are carried out on ramps and areas for parking & maintenance are called aprons.
Many people feel very frightened when they travel by plane, but you may not know that, in fact, air travel is statistically the safest form of motorized transport known to man! Today it is estimated that there is only one fatality for every 2,000 million person-miles flown in the air. Accurate communication between the pilot and the ground is obviously fundamental for air safety, and indeed many accidents are caused when this information is inaccurate or provided too late. Four out of five accidents occur during take-off or landing procedures, that's why you must always seat with your seatbelt fastened during these procedures and you are not allowed to use electronic devices.
Another cause of accidents could be the presence of ice or snow on the wings, which increases the weight of the plane, requiring a higher speed to avoid stalling.
Engine failure rarely causes accidents in large aircraft because they operate with several engines, so an emergency landing is usually possible.
When an airplane flies through volcanic ash its engines can lose power completely. Today, meteorological information is so precise that airspace is simply closed in the presence of volcanic ash, as in the case of the eruptions in Iceland in 2010.
Aircraft safety is improving all the time. However it is important to read carefully and know all the safety indications on the passenger safety card.
Road and transportation:
The GPS System
GPS, which stands for Global Positioning System, is a radio navigation system belonging to the American Ministry of Defense, that allows land, sea, and airborne users to determine their exact location, velocity, and time 24 hours a day, in all weather conditions, anywhere in the world .
The complete name of the system is NAVSTAR GPS, which means 'Navigation Satellite Timing And Ranging Global Positioning System'. It was born as a top secret project of the American Department of Defense during the final years of the Cold War so initially it was intended just for military purposes.
Today the GPS service is provided free of charge by the United States Air Force to the entire world. It is a constellation of satellites (21 active and 3 spare ones) orbiting at 11,000 nautical miles above the Earth and a series of ground stations that control and monitor those satellites. The satellites are spaced so that from any point on Earth, four satellites will be above the horizon.
On the ground, any GPS receiver contains a computer that 'triangulates' its own position by getting bearings from three of the four satellites. The result is provided in the form of a geographic position - longitude and latitude - for most receivers , with in a few metres. If the receiver is also equipped with a display screen that shows a map, the position can be shown on the map. When a fourth satellite can be received, the receiver/computer can calculate the altitude as well as the geographic position. If you are moving, your receiver may also be able to calculate your speed and direction of travel and give you estimated times of arrival to specified destinations.
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