Air Traffic Control keeps you flying in safety
If you're planning to fly in the near future, you'll be glad to know the chances of a mid-air collision are extremely low. For example, recent statistics for one year's flying in the USA showed an average of just one accident for every 334,448 hours in the air - an impressive safety record, thanks largely to the nation's effective air traffic control system.
Although primary responsibility for an aircraft’s safety rests with the pilot, there are times when he or she is unable to see other planes nearby, and this is when ground crew are on the alert, serving as eyes and ears. Traffic controllers line the route, following the flight from departure to landing, so the pilot has radio contact with qualified specialists every inch of the way. As an added precaution, both pilots and controllers have a range of radios and frequencies – so if one fails, there is always back up.
Each aircraft is guided by directional radio transmitters on the ground. These navigation aids emit signals telling the pilot his exact position while monitoring other planes in the vicinity. By the time a pilot sees another plane, there may only be seconds for evasive action. Trained air traffic controllers, however, will sound the warning well in advance and navigate both aircraft out of danger.
Traffic controllers also use radar to picks up radio waves that bounce off airplanes and show up as objects, or targets, on the controller’s radar screen. Many airplanes are equipped with a transponder, which returns an identification signal to the radar and, when combined with computer input, identifies the aircraft on the radar screen, complete with flight number, speed, altitude, and aircraft type.
Planning is, of course, vital. Before take off, pilots file a proposed flight plan and the traffic controller is given a copy of this in the form of a flight progress strip which highlights the intersection points. On passing over each of these points, the pilot reports to the controller who in turn marks this on the flight strip.
For international flights, miscommunication can be dangerous. To avoid this, the Civil International Aviation Organisation uses English as the universal language. Any similar sounding words, letters, or numbers given over the radio are distinguished by standard phrases and pronunciation when giving instructions from the ground while, as an added security measure, pilots are asked to “read back,” or repeat directives given by controllers.
An air traffic controller faced with a potential collision has several options: He may instruct the pilot to change direction by ‘vectoring’ the craft; to alter speed to overtake another plane; or to change altitude, ducking under or rising above the oncoming danger.
The Goal—Your Safety
Plans are already being implemented to enhance the air traffic control system. Earth-based navigation systems often require restricting aircraft to specific routes and altitudes. This results in wasted airspace and longer flight routes. Future flights will rely even more on satellite-based systems, such as the Global Positioning System, which will allow for much more flexibility in routing airplanes and will result in easier control of transoceanic flights.
Air traffic control systems are constantly being enhanced to make flying simpler and safer. The problem with earth-based navigation is it restricts airlines to set routes and altitudes. Satellite technology, such as the Global Positioning System, will eventually free up airspace and shorten journeys as it gradually replaces earth-based navigation which restricts airlines to specific routes and altitudes.