All the systems are integrated to form a whole while affording the individual systems the benefit of individuality via Virtual Private Networks (VPNs) while sharing a common communications system. To examine the anatomy of this system let us follow a passenger through the system and have a peek at what happens behind the scenes.
We will assume that the ticket was already purchased via the internet which is the first step in the process. The e-ticket is logged by the airline on their flight database when you purchase it and it is linked to an ID number or passport number.
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| Fig. 2: Typical FIDS. | Fig. 3: Typical CUTE stations |
Arrival and check-in
On arrival at the airport the first system you are likely to encounter is a parking management system assuming you arrive by car. This system will direct you to an appropriate parking area that has available parking. A ticket is issued which is coupled to the vehicles registration number obtained via a CCTV system using Licence Plate Recognition (LPR) software. The available parking spot in the parking area will be indicated and flagged. All the above is controlled by the Parking Management System (PMS) (poor choice of acronym). This system keeps track of available space as well as the billing for the parking.
Our intrepid traveller will now proceed to the terminal building. The traveller will now encounter the first of the systems that will keep him informed. The Flight Information Display System (FIDS) shows all the flights to and from the airport as well as their flight status and the check in area to be used for the flight or the arrival gate.
The FIDS is coupled to a central database called the Airport Operational Database (AODB) and an Automatic Voice Announcement System (AVAS). All the flight information is stored in the AODB covering past and future flights for a period of at least a year. The FIDS display data is obtained directly from the AODB. Flight announcements are derived from the FIDS and sent to the AVAS to articulate the appropriate announcement.
Two routes of check-in are available, self service via a Common Use Self Service (CUSS) terminal or at the airline counter where a Common Use Terminal Equipment (CUTE). The system requires your ID or passport number. This can be scanned or manually entered. A boarding pass is issued and bag tags placed on hand in luggage. The boarding pass details are fed into the Departure Control System (DCS) or Local DCS (LDCS). The barcode on the luggage is linked to the boarding pass. There is a movement to the use of RFID tags for baggage at some airports but if there is no RFID facilities at the destination then barcode tags have to be used as well. The bag tag information is coupled to a Baggage Handling System (BHS) which sorts baggage and routes it to the correct flight loading position where the baggage tag is scanned and the bag loaded into a container or directly on a dolly for loading in the baggage hold of the aircraft. The BHS keeps track of the bag until it is on the aircraft. From here the information is passed to the Baggage Reconciliation System (BRS) and then to World Tracker to track the luggage to its final destination.
Security and immigration
Meanwhile our intrepid traveller now passes to a security check point where his hand luggage is X-ray scanned and he passes through a metal detector.
Unknown to him his hand in luggage is also scrutinised and scanned in the BHS system by passing through one or two stages of screening. First level is a 2D scan, if the item appears to be suspicious it is 3D scanned and if still suspicious it will be hand searched in the presence of the owner.
An international traveller will now have to pass through emigration where the passport is controlled and stamped. The scanning of the passport will couple it to the boarding pass and stored in a database. It is also checked against a “wanted” or “black” list in a data base. Another form of automated immigration is via a Biometric Immigration Gate (BIG). The passenger pre-registers and is issued a smart card. This card will contain all the passenger’s details as well as a finger print or retina scan for positive ID. The card is swiped and if valid the entrance gate opens. Inside the card is swiped again and a finger print or retina is scanned. The ID is checked against the same “wanted” or “black” list database. After a clean check the exit gate opens and the passenger walks through. Cameras and weight sensors check for one person at a time. Any violations will raise an alarm and secure the entrance and exit gates. Failed recognition opens a side gate and allows the passenger to go to a manned gate.
CCTV is extensively used to monitor the terminal building. The cameras form part of an Integrated Security Management System (ISMS). Cameras are intelligent and can detect unattended baggage which will be alarmed. The same system is deployed along the baggage conveyors of the BHS and will alert operators of unauthorised persons near the conveyor as well as conveyor stoppages and breakdown. The ISMS also manages the access control of airport staff
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| Fig. 4: PCA yellow pipeand 400 Hz power. |
Boarding and departure
After passing security and immigration the passenger is in a departure hall. Here he is kept informed about the flights via the FIDS and AVAS. These systems are area dependant and displays and announcements are tailored to the area.
To get the aircraft to the correct boarding gate/stand other behind the scenes systems come into operation.
An Airport Resource Management System (ARMS) will allocate a stand position to the aircraft and assign resources to it. This will include refuelling via a fuel hydrant or Bowser, 400 Hz ground power supply to the aircraft as well as Pre-Conditioned Air (PCA) systems which supplies an air-conditioning point or points to the aircraft so that the onboard systems do not have to operate to cool/heat the aircraft. Catering is also part of this system. The number and type of meals required for the flight and any special dietary requirements of passengers can be flagged as required.
Parking the aircraft at a passenger boarding bridge is a precision operation with 100 mm margin for error. A Visual Docking and Guidance System (VDGS) is used to aid the pilot. This system will get aircraft details from the ARMS and then use LASER techniques to identify the aircraft from the aircraft type expected at the gate and guide it to the stopping position. If the wrong aircraft is taxing into the position, the system will recognise this and visually inform the pilot to stop.
Once the aircraft has docked, it can be prepared for its next flight. Wireless LAN using position information by triangulation to three or more wireless access points activate a position based application on a wireless portable device, palmtop etc. This allows operators only the pertinent menus based on their position in relation to the aircraft, e.g. if the operator is under the wing then a refuelling menu will be available.
In a similar manner all services are catered for.
With the aircraft serviced it is ready for its next flight and passenger boarding commences. At the boarding gate the boarding pass is read and reconciled with the passenger list. This is controlled by the Departure Control System (DCS) for international flights and a Local DCS (LDCS) for domestic flights.
When the boarding gate is closed and a reconciliation is done with the passenger list any missing passengers are flagged. If these passengers do not respond to the last calls for boarding, their baggage is located via the BRS system and removed from the aircraft.
Flight
Pushback and taxiing is next. The Airfield Ground Lighting (AGL) system consists of individually addressed light fittings indicating the taxiway centreline and/or edge. Using proximity detectors and control from the ATC, vis a SCADA system, only the required route to the runway is lit. As the aircraft taxies past a detector the lights behind it are turned off. The system can be used to only light up the taxiway for 150 m to 200 m in front of the aircraft as a type of “follow me” control. This system removes confusion and saves energy.
The same system is used on the runway. Runway centreline and edge are controlled and only turned off behind the aircraft while the full runway ahead is turned on.
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| Fig. 5: Typical AWOS. |
Meteorological systems
Every airport has an Automatic Weather Observation Station (AWOS). This gives information on wind speed and direction at three places along the runway because wind direction and speed can change over the length of the runway (4,5 km in some instances). Precipitation and rate at either end as well as barometric pressure and temperature at either end. These conditions can affect the takeoff and landing characteristics of an aircraft.
Navigational aids
To help the pilot find his way he can rely on the onboard Global Navigational System (GNS). This is an accurate version of a terrestrial GPS system. As backup he can use radio beacons coupled to Radio Direction Finding (RDF) systems and the radio compass. The pilot files a standard flight plan with the ATC which details the proposed route and expected time of arrival at the destination.
Approach landing and arrival
The first contact the pilot will have with an airport is via radio and RADAR. The pilot then comes into range of Doppler VHF Omni-directional Radio range (DVOR). These systems will position the aircraft into the correct approach for the runway. As the aircraft gets closer the Instrument Landing System (ILS) will align the aircraft on the centre line and the correct glide path for landing. The ATC will turn on the appropriate runway lighting consisting of edge l, centre line, touchdown zone, threshold and end lights as a visual aid to the pilot. A further visual aid is the Approach lighting system that extends for 900 m beyond the runway threshold to align the aircraft with the centre line of the runway and Precision Approach Path Indicators (PAPI) which will alert the pilot if his approach is too high or too low. The AGL system includes the lighting on the runways, taxiways and approach.
Contrary to popular belief the airport’s main purpose is to allow aircraft to take off and land safely. This is achieved with a system of runways and interlinking taxiways.
As for departure the aircraft is guided to the correct stand using the same system of controlling the AGL. The VDGS will do the final guidance to the stopping position.
Arrival and baggage collection
Passengers on international flights will first pass through immigration as was the case with departure. No security checks are carried out on arrivals but customs clearance might be required.
The unloaded baggage is placed into the BHS system which will route the bags to the correct carrousel for pickup. The BHS will also scan the bag tag, either barcode or RFID and reconcile with the bag tracking system.
In the arrivals hall you could encounter an Information Kiosk (IK) which will help you find your way through the airport. This is a browser based system getting its information from various sources including the internet, airport intranet, airline intranet etc.. This system can be used to check hotels taxis, trains, busses, connecting flights etc. and will allow you to book online.
