3. What is Air Traffic Control..?
Air traffic control (ATC) is a service provided by ground based Controllers who
direct the Aircraft on the ground and through controlled Air Space and can provide
advisory Services to aircraft in non-controlled Air Space.
To prevent collisions ATC enforces Traffic Separation Rules, which Ensure each
aircraft Maintains a Minimum amount of Empty space around it all times.
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4. Extended Services
In many Countries, ATC provides services to all private , military and commercial
aircraft operating within it’s Air space.
Many Aircrafts also have Collision avoidance systems , which provide additional
safety by warning pilots when other aircrafts gets close.
The Pilot in Command is the final Authority for the Safe operation of Aircraft and
in an emergency he may Deviate from ATC instructions to maintain Safe
operation of Aircraft.
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5. History
In 1921, Croydon Airport, London was the first airport in the world to introduce Air
Traffic Control.
The first ATC tower regulating all activities of aircraft at a specific airport , opened
in Cleveland in 1930
Approach/departure control facilities were created after adoption of RADAR in the
1950s to monitor and control the busy airspace around larger airports.
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7. Operations Linked with ATC
Airport Control
Ground Control
Local Control / Air Control
Approach and Terminal Control
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8. Airport Control
Air Traffic Controllers are responsible for the separation and efficient movement
of aircraft , and also vehicles operating on the taxiways and runways of the
airport itself, and aircraft in the air near the airport, generally 5 to10 nautical miles
(9 to 18 km) depending on the airport procedures.
Controllers may use a radar system called Secondary surveillance RADAR for
airborne traffic approaching and departing.
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9. Airport control tower Inside view of a Seattle-
Tacoma International Airport
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11. Ground Control
Ground control (sometimes known as ground movement control) is responsible for
the airport "movement" areas, as well as areas not released to the airlines or other
users.
This generally includes all taxiways, inactive runways, Holding Areas, and some
transitional aprons or intersections where aircraft arrive, having vacated the runway
or departure gate.
Any aircraft, vehicle, or person walking or working in these areas is required to have
clearance from Ground Control.
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12. Holding Areas
They are provided at busy airports near the
runways. ? They hold Planes Before its Takeoff
to wait till the runway is cleared.
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13. Local control / Air control..
If local control detects any unsafe condition, a landing aircraft may be told to “Go-
Around" and be re-sequenced into the landing pattern by the approach or terminal
area controller.
Ground control must request and gain approval from local control to cross any
active runway with any aircraft or vehicle.
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14. Approach & Terminal Control
Many airports have a radar control facility that is associated with the airport. In
most countries, this is referred to as Terminal Control. In the U.S., it is referred to
as a TRACON (Terminal Radar Approach Control). While every airport varies,
terminal controllers usually handle traffic in a 30-50 nautical mile (56-93 km) radius
from the airport.
Terminal controllers are responsible for providing all ATC services within their
airspace
Traffic flow is broadly divided into departures, arrivals, and Over –flights
Terminal control is responsible for ensuring that aircraft are at an appropriate
altitude when they are handed off, and that aircraft arrive at a suitable rate for
landing.
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15. RADAR coverage
Long Range Radars are used and are Capable Enough at higher altitudes, to see
aircraft within 200 nautical miles (370 km) of the radar antenna.
A Radar Archive System (RAS) keeps an electronic record of all radar information,
preserving it for a few weeks.
When an aircraft has 'disappeared' from radar screens, a controller can review the
last radar returns from the aircraft to determine its likely position.
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16. Problems Faced by ATC
Two Major Problems :
1. Traffic
2. Weather
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17. Aircraft Traffic & Weather
Traffic at Airport
Arrivals of Flights
Departures
Hopping Aircrafts
Layovers
Availability of Aero Bridges
Vacant Runways
Weather Conditions
Heavy Rains
Low visibility of Runway and aircraft
Thunderstorms
Turbulence
Crosswinds at Airport
Heavy Snow Fall
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21. Call Signs
In order to ensure safe Air Traffic separation Call signs are Used by Air Traffic
Controllers
These are permanently allocated by ICAO (International Civil Aviation
Organization) on request usually to Scheduled Flights and some air forces for
Military Flights.
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