AIR TRAFFIC CONTROL
Air traffic Control is a service provided by air traffic controllers which are situated on the ground. They also perform the task of assisting the pilots from time to time and also in the need of an emergency. However their primary functions is to prevent airplanes from colliding with each other and overall , expedite and organize the flow of air traffic. These air traffic control systems are also used in militaries, to guide and assist fighter jets.
Air traffic control(ATC) are also used to provide service to all private, passenger and military aircraft which are within its range of airspace. ATC’s have a set of guidelines, standards and rules which they are to follow. It is optimal for every aircraft to maintain minimum amount of empty space around it at all times, but in cases of emergencies the pilot in command is the final authority of the aircraft and may deviate from the orders or guidelines from the ATC.
Brief history of ATC
Corydon airport, London in 1921 was the first airport to introduce air traffic control to the world. The development of the air traffic control usually began during the first world war, where the US post was using methods and techniques developed by the army to guide and direct reconnaissance aircrafts.
Technologies used in Air traffic control
Flight data processing systems: These are basic software used to process all the basic information related to the flight, typically in the time horizon from gate to gate.
Short-term conflict alert(STCA): It checks for conflicting trajectories which are possible and alerts the controller or pilot. It also provides information as to how to turn, descent and climb without infringing on altitude clearance.
Minimum safe altitude warning(MSAW): This tool used to alert the pilot wether the aircraft is flying too low to the ground or will come in contact with the terrain based on its current flight pattern.
System coordination(SYSCO): Used by the controller to mediate the release of flights from one sector to another.
Area penetration warning(APW): To inform the controller that the flight is penetrating into a restricted area.
The departure manager(DMAN): Is a system used to calculate the departure flow and maintain maximum throughput at the runway.The arrival manager time(AMAN): This system calculated planned departure flow and avoids congestion and queuing up the runway.
Converging runway aid(CRDA): Enables the controller to simulate two final approaches that intersect and makes sure that go around are minimized.
Centre TRACON automation systems(CTAS): It is a suit of tools which support human controller in decision making, this was developed by NASA Ames Research centre.
Some of the many tools developed are:
Traffic Management Advisor(TMA)Passive Final approach tool(pFAST)Collaborative arrival planning(CAP)Direct-to(D2)En Route descent advisor(EDA)Multi-center TMA
MTCD: Used in Europe , the several tools available are iFacts(MATS), VAFORIT, new FDPS.
URET: Used in the United States is a tool used to display that shows all the current aircraft that are routed into the sector.Mode S: System used to provide information also via secondary surveillance radars allowing radar processing systems and controllers to see various data on a flight.
CPDLC: Controller-pilot data link communications: Allows digital messages to be sent between controllers and pilots, this avoids the need to use radiotelephony. This is used mostly in area of rough climate and terrain difficulties.ADB-B: Automatic dependent surveillance broadcast: It is a system which consolidated the data of various flight parameters to air traffic control systems, the most important data of the aircraft is it latitude and longitude, and level.The electronic flight strip system(e-strip): These are electronic flight strips the are replacing old paper strips which increases the efficiency and reliability of the overall functioning of the ATC.
Problems related to ATC
Traffic is major factor contributing to the problems faced by airports, and the day-to-day task of the ATC is to deal with this traffic and make the process efficient, i.e. coordinating the arrival and departure of the volume of aircrafts. Many factors dictate the amount of airplanes that can land on the runways at a given particular amount of time. Each aircraft while landing, must touch down, slow down, and exit the runway before the next landing aircraft crossed the approach end of the runway. Every runway of each airport has a certain limit of aircraft arrivals and departures which it can handle. The problems arise when an airliner schedules more arrivals into an airport than it can handle, in such cases aircrafts must be holding over locations specified by the ATC at particular altitude and such credentials.
Beyond runway and traffic issues, weather is a major factor which contributes to the problems faced by ATCs. Rain, ice, snow, or hail, cause the aircraft longer to slow down and exit and in extreme conditions, aircrafts lose control and slide of the pathway leading to catastrophic situations. Fog is another which severely reduces the visibility of the pilots as well as controllers. This also increases the airborne delay for holding aircraft. In Area Control Centres, thunderstorms are a major problem , controllers have to reroute the path of the aircraft around the storm, using en-route systems.
