 |
You can
choose planes on the monitor with a magnifying glass. The programme shows you the real-time location plus flight details of each plane. |
All commercial flights that are currently in North American air space as well as over the Atlantic and Pacific Oceans are represented. All information might not be available of each plane all the time. The information is based on the Live Flight Data service of AirNav Systems corporation. Thus, the information is received directly from the US FAA = Federal Aviation Administration.
According to international aviation regulations all commercial flights must regularly send their registration number and flight details by radio. Details are to be sent with a so called transponder, and they are received with special radars. The information is then transferred to the data system of flight control. Flight control can monitor the traffic in its air space and anticipate traffic jams and danger situations.
Co-operation partner:
Finavia
THE FLIGHT CONTROL SYSTEM
Flight control is a complex yet clear
and strictly regulated system. Flight control systems can be
divided into different categories out of which the most interesting
from the passenger’s point of view is the division between
“visible” and “invisible” flight controls.
The flight control tower in airports is the only visible unit. But
it is by no means the only place where flight controllers work. As
a matter of fact, a lot of flight control is performed in approach
flight controls and area control centres. They can be situated just
about anywhere although they are usually close to airports. In all
of the above mentioned units, the main work tool of a flight
controller is the aviation radio. Each flight control unit has its
own radio frequency through which it is in contact with aircrafts
under its supervision. The flight control system is international
and it functions everywhere in the world.
CONTROL ZONE FLIGHT CONTROL (TWR – aerodrome control tower)
The flight controller in the tower is in charge of runways and
taxiways and the control zone CTR. CTR refers to the air
space in the immediate vicinity of the airport up to an altitude of
about 400 metres. TWR is in charge of the prevention of collisions
both in air and on ground.
The control zone flight controller uses mainly his/her sight as a
work tool: he/she looks out of the window and gives aircraft and
vehicles permission to move in the traffic area. TWR gives
permission to lift off and land after making sure that the runway
is free. TWR works closely with approach control, if there is one
available. (For example there is a combined TWR/APP in Oulu and
Turku. All flight control operates from the tower.) There can be a
separate flight controller in the tower for ground traffic GND
depending on the amount of traffic. The GND controls traffic on
taxiways. If this is the case, the TWR flight controller is in
charge of the runways and control zone.
APPROACH FLIGHT CONTROL (APP)
The approach flight control of the terminal control area TMA
is superior to the control zone flight control. The
size and shape of TMA can vary from one airport to another, but
usually it consists of airspace between 400 metres (starting
from the TWR limit) and FL95 (9500 feet or 2900 metres).
Horizontally the TMA covers an area of about 40 km from the airport
in every direction. At Helsinki-Vantaa the TMA is larger reaching
up to FL245 (24500 feet or 7500 metres) and covering a radius of
55-90 km.
Approach flight
controls can be so called method flight controls or radar flight
controls; in Finland all separate approach flight controls are
radar flight controls (TAR – terminal area surveillance
radar).
A radar or method flight controller is in charge of the prevention
of collisions in his/her area. He/she also makes sure that aircraft
are never too close to each other according to certain standards.
This is called separation. There are dozens of aircraft separation
minima but the most common ones are: vertical distance 1000 feet
(300 metres), horizontal distance on radar 5 sea miles (about 10
km) and horizontal distance within the vicinity of the airport 3
sea miles (about 6 km). The flight controller has to use several
different methods to make sure that at least one of the aircraft
separation minimum is valid.
The radar flight controller can see the geographical location of
aircraft, their altitude and speed on the radar. The flight
controller has the flight plans FPL of aircraft so he/she knows
where each plane is heading for. If the aircraft are too close to
each other the flight controller shall order changes in their
altitude, direction and speed and thus maintain separation.
On busy airports the approach flight control can be divided into
different responsibility areas. For example on Helsinki-Vantaa,
during busy hours, there are two RADs (radars that monitor
departures and incoming traffic still far away) and two ARRs (ARR =
incoming radar that decides the final order of landing aircraft).
On airports with an air force base there is also a precision
approach radar PAR. It’s possible to “talk
through” a landing of an aircraft with the PAR even in
terrible weather conditions. Planes perform the final approach with
aid of landing instruments (ILS, instrument landing system).
The airports that do not have radar at their use usually combine
control zone and approach flight control (TWR – APP). This
means that the same flight controller in the tower is in charge of
traffic in all zones: the traffic, control and approach zones.
Responsibility and tasks are identical to the ones in separate
units.
AREA CONTROL CENTRE (ACC)
The area control centre takes charge of traffic in air space areas
that are not under the responsibility of an airport flight control.
This area is called FIR – flight information region.
The Finnish air space area is Finland FIR (EFIN), and it has been
divided into two responsibility zones: Tampere ACC (EFES) and
Rovaniemi ACC (EFPS). The border between these two lies south of
the Oulu and Kajaani axis.
ACC can be based either on radar or method. In Finland radars are
being used. One could say that the whole globe has been divided
into area control centres’ responsibility areas. ACC
separates traffic with the same principles as APP. The entity under
area control centres’ responsibility can be divided into
sectors. For example the air space of Tampere area control centre
has been divided into five sectors and three Feeder-sectors
directing traffic to Helsinki-Vantaa. The air space of Rovaniemi
area control centre has been divided into two sectors on top of
which more sections can be formed during high season winter
traffic. ACC controls air space and grants air space reservations
to for example air forces, gliders etc. ACC gives permission to
rehearsal shootings of the armed forces and co-operates with other
ACCs.
For more information
Suomen lennonjohtajien yhdistys
Updated 8.1.2007/KT
