Module 2: The Airside PDF

# Module 2: The Airside ## Module Introduction - In Module 1, you learned about the basic functions of an airport. - The airport is made up of three distinct areas: airside, terminal, and landside. - This module will focus on the facilities that make up each of these areas. ## What is a System? -...

# Module 2: The Airside ## Module Introduction - In Module 1, you learned about the basic functions of an airport. - The airport is made up of three distinct areas: airside, terminal, and landside. - This module will focus on the facilities that make up each of these areas. ## What is a System? - A system is a constellation of several components that work together towards a common objective. - Partners working on an airport must work together. - No process, service, or product at an airport stands alone. - Components include people in several organizations with different targets, tools, and qualifications. - For example, a defect signal on the City Train feeding the airport will cause delays for many flights. - If any component in the system cannot meet an agreed target, the whole system will suffer. ## The Key Success Factors within an Airport are: - **Standardization**: Predictability, stability, and known (and understood) activities from operating partners enables the system to manage complex procedures, interactions, and make best use of available infrastructure. - **Interface Management**: Standardized procedures and equipment are not enough. Individual processes rely on delivery or pick up by another process. The system's components must work together and match other requirements. - **Situational Awareness**: Knowing (ideally in advance) what is happening around one's own activities enables them to work effectively and efficiently. - As an industry prone to unexpected changes (like a late arriving flight, a broken passenger bridge, or a lost bag in the terminal triggering security activities), we must adjust our activities to keep up so that we deliver according to expectations. ## Optimizing Joint Efforts - By understanding and managing all airport activities like a system, we can optimize our joint efforts. - This will increase productivity, service quality, staff health and satisfaction, customer experience, and enables airlines to offer the product their market expects. # 2.1: The Airside ## 2.1.0: Unit Overview - This unit will define and describe the physical and service components that make up the airside. - It will explain their functions and define their providers. - It will then explore operational procedures that airport operators should develop and maintain to manage their aerodrome safely, effectively, and efficiently. ## 2.1.1: Physical Components of the Airside ### 2.1.1.1: The Movement Area - The movement area is part of an aerodrome used for the take-off, landing, and taxiing of aircraft. - It consists of the maneuvering area and the aprons. #### 2.1.1.1.1: Maneuvering Area - The maneuvering area is the part of an airport used for the take-off, landing, and taxiing of aircraft, excluding aprons. ##### Runways - A runway is a defined rectangular area on a land aerodrome prepared for the landing and take-off of aircraft. - Runways can consist of a hard surface (asphalt or concrete) or be made of sand or gravel. - Jet engines, sensitive to the ingestion of loose material, can only serve light, propeller-driven aircraft. ###### Orientation of Runways - Aerodynamic considerations dictate that aircraft take-off and land facing into the wind. - This reduces the ground run required to become airborne or to decelerate and stop. - Since wind direction fluctuates, runways must be constructed in a way aligned with the prevailing wind conditions of the proposed site. - This ensures that the runway will be reasonably aligned with the wind. - The runway orientation also needs to be balanced with the surrounding terrain to avoid limitations in the flight profile or unacceptable noise emissions to sensitive areas. ###### Numbering of Runways - Runways are numbered from 01 to 36. - This number represents the magnetic orientation of the runway, rounded to the nearest 10 degrees. - The last digit of the number is then dropped. - For example, a runway with a magnetic orientation of 053 degrees, is rounded up to 050, the end zero is dropped, and the runway is called “05”. - When an airport has two, three or more parallel runways, the letters R, C, and L for Right, Center, and Left are added. - For example: runways 06R-24L, 06C-24C, and 06L-24R. ##### Number of Runways - Many airports have more than one runway, sometimes four and more. - Multiple runways can converge, intersect, or parallel. - The first reason for multiple runways is that aircraft must operate in cross wind conditions. - For illustration purposes, light single-engine aircraft can sustain 10 knots of crosswind. - Larger aircraft can sustain 13 knots and large multi-engine aircraft can sustain 20 knots. - Operations become unsafe beyond these values. - When there is substantial time with crosswind exceeding the aircraft’s capabilities, another runway called a secondary runway is required. - This runway is generally shorter than the primary runway because when the crosswind on the primary runway is too strong, the head wind on the secondary runway will allow for a shorter take-off and landing run. - ICAO breaks down aircraft into three categories according to their crosswind capabilities: 10 knots, 13 knots, and 20 knots. - ICAO recommends that on a runway, 95% of the time there should be one direction available for landing or take-off, considering the crosswind limitations of the aircraft. - This is called the usability factor. - If excessive cross wind exists more than five percent of the time, a secondary runway is required. - The second reason for multiple runways is runway capacity. - When demand exceeds runway capacity, aircraft must wait to take-off or land. - This results in delays, inconvenience for passengers, and operational problems for airlines and the airport operator. - By adding one runway (if they can be used simultaneously), the airport’s capacity will increase. - Large airports with high traffic volumes sometimes have parallel runways, one for take-offs, one for landings. - A third runway, oriented in accordance with prevailing crosswind conditions, will provide the recommended usability factor. ###### Length of Runways - The length of a runway must be sufficient to accommodate the operational requirements of the critical aircraft. - Heavy aircraft require a longer runway to take off and land than light aircraft. - Air temperature and aerodrome elevation also negatively affect aircraft performance. - Runway length ranges from a few hundred meters to 4000m or more. ###### Width of Runways - The width of a runway is a function of its length. - It ranges from 18 meters to 60 meters. ###### Strength of Runways - Runways must be of sufficient strength to accommodate the mass of the critical aircraft. #### 2.1.1.1.2: Taxiways - A taxiway is a defined path on a land aerodrome established for the taxiing of aircraft. - It provides a link between one part of the aerodrome and another. - They usually connect aprons and runways. - There is a special type of taxiway called a rapid exit taxiway. - Located along the runway at 30 degrees, a rapid exit taxiway allows aircraft on the landing roll to exit at a higher speed. - This reduces the runway occupancy time, and increases the runway’s capacity. - The width of a taxiway must be sufficient to meet the requirements of the critical aircraft. - They range from 7.5 m to 23 m. - Letters, in alphabetical order, designate taxiways (for example, taxiway Alpha for “A”). - Taxiways must be of sufficient strength to accommodate the mass of the critical aircraft. #### 2.1.1.1.3: Aprons - An apron is a defined area on a land aerodrome intended to accommodate aircraft for loading or unloading passengers, багаж, mail, or cargo, fueling, parking, or maintenance. - There is a special type of apron called a central De-icing Pad. - At airports where snow and ice conditions are frequent, air safety requires that departing aircraft be free of any accumulation of snow, ice, and frost. - This is done by spraying a mix of water and chemical that melts the contaminants and prevents further accumulation during taxi, take-off, and initial climb. - De-icing pads must be located in close proximity to runways. - De-icing procedures can be lengthy. - The requirement for all aircraft to go through a central facility may cause congestion and delays. - Close coordination between the de-icer, apron- and air traffic-control is required to minimize these effects. ###### Apron Size - The size of an apron must be sufficient to accommodate the number of aircraft expected at peak times, plus adequate circulation. - Each aircraft is parked on a defined surface called a stand. - A number designates each stand. - Aprons must be of sufficient strength to accommodate the mass of the critical aircraft. ## 2.1.1.2: Visual Aids - Visual aids provide pilots with visual reference while taxiing, landing, and taking off. - Visual aids are provided by the airport operator. - There are four categories: indicators and signaling devices, paint markings, signs, and lights. - Visual aids serve three purposes: to help navigation, to denote obstacles, and to denote restricted areas. ### 2.1.1.2.1: Visual Aids are Numerous and Diverse - They apply differently to different categories of aerodromes and can vary with local conditions. - It is helpful to know the most common types. - This will allow you to easily identify them and their purpose at your aerodrome or any location. #### Wind Direction Indicator - This is a prominent feature on all aerodromes. - It is a white and orange truncated cone, made of fabric. - It is located near the runway threshold and mounted on a high post. - Its purpose is to provide pilots with visual indication of the direction and speed of the wind. #### Landing Direction Indicator - This is a T-shaped, horizontally mounted indicator. - It can be rotated and set in the direction of the runway in use. - These devices are particularly useful at airports where there is no control tower, or where aircraft not equipped with radio operate. - They confirm the information provided to pilots when used in conjunction with radio communications. #### Signaling Lamp - It is a portable, multi-color light. - It is located in the control tower and used by air traffic controllers to provide pilots of aircraft not equipped with radio, with visual instructions such as clearance to land or take off. #### Pavement Markings - These consist of markings painted on the aerodrome pavement. - They serve the same purpose as the painted markings you see on roads and streets. - They provide pilots with visual information that helps them navigate. - Common markings include: - Aiming - Center Line - Touch Down - Number - Threshold #### Threshold Markings - Seen from the air, the threshold of a runway is not always visible because of lack of contrast between pavement and surrounding terrain. - Threshold markings indicate the beginning of the usable pavement area. - They consist of a pattern of longitudinal narrow stripes. #### Aiming Markings - These are longitudinal rectangles located exactly 300 meters from the runway threshold. - They allow pilots on approach to visualize the landing area from a distance. #### Touchdown Zone Markings - These are longitudinal stripes located on either side of the centerline extending several hundred meters from the threshold. - They provide pilots with visual information relative to the area within which landing aircraft should touch down. #### Runway Side Stripe Markings - These are longitudinal stripes located along the two edges of the runway. - They provide a good reference when there is no contrast between the pavement and the surrounding ground. #### Taxiway Centre Line Markings - These look like the lines painted on the center of roads. - They serve a different purpose: they provide guidance for pilots to ensure that their aircraft remains well within the taxiway surface, when following the center line. - All taxiway markings are yellow. #### Taxi Guidance Lines: Different color lines may be used to indicate the path to follow for designated areas of the apron. #### Runway-holding Position Markings - While waiting to access a runway, aircraft must remain at a safe distance from the edge of the runway. - This position is shown with a combination of solid or solid and dashed transverse lines painted across the taxiway. - Special markings warning of the proximity of a runway may also be painted on the taxiway, ahead of the taxi-holding position marking. #### Aircraft Stand Markings - When approaching their assigned stand, pilots must be able to identify its location. - The end of the taxiway center line contains a lead-in line (which points the aircraft in the right direction), a stand identification marking (its number), and a stop line (which positions the aircraft accurately on a stand). - Other markings can include a lead-out line, which provides guidance when departing from the stand. #### Apron Safety Lines - For safety reasons, it is important to separate ground support equipment from the path of an incoming aircraft. - This is achieved using red lines delineating the area where equipment can safely be parked while the aircraft is moving. - Red-hatched lines sometimes supplement them. #### Lights - Painted markings are useful during daytime and good visibility conditions. - However, since operations during nighttime and low visibility conditions are necessary, other visual aids are required. - Lights, more effective than markings in low visibility conditions, are used. - There are many types of aerodrome lights, each type serving a specific purpose. #### Aerodrome Beacon - Seen from the air, aerodromes are not necessarily easy to identify visually. - This is especially true when highly developed urban areas surround the aerodrome. - For this reason, an aerodrome beacon is installed at all aerodromes intended for night use. - It shows either colored flashes alternating with white flashes or white flashes only, with about twenty flashes per minute. - It is often installed on top of the control tower or other prominent airport structure. - You can easily see it If you stand on an open area with good view of the aerodrome. #### Approach Lighting Systems - Pilots who fly in IMC (Instrument Meteorological Conditions) require guidance during their approach to the runway. - Two types of guidance are required: visual and electronic. - In this section, you’ll explore visual systems. - They are always used in conjunction with electronic aids. - One of the key components of visual guidance is the approach lighting system. - Approach lighting systems all serve the same purpose: to provide pilots approaching in low visibility or ceiling conditions with a visual reference of the runway extended center line and of their distance from the threshold. - They consist of one or more rows of bright lights, mounted on posts, and installed along the extended centerline of the runway. - They extend from the runway threshold to a distance of up to 900 meters, depending on the type of approach. - Cross bar lights provide distance information. - They are located at 300 meters from the threshold. ##### Visual Approach Slope Indicator Systems: - Runways used by jet aircraft or runways where the approach area does not provide adequate vertical reference must be equipped with a vertical visual guidance system. - Two main types exist: the Visual Approach Slope Indicator System (VASIS) and the Precision Approach Path Indicator (PAPI). - Both systems provide pilots of approaching aircraft with visual information as to whether the aircraft is approaching along an adequate slope, or whether it is too high, or too low. - VASIS and PAPIs consist of a number of directional lights, installed on the side of the runway near the touchdown area. - Depending on the position of the aircraft in relation to the proper approach slope, the pilot will see various combinations of red and white lights. #### Runway Threshold Identification Lights - When the threshold of a non-precision runway is not conspicuous, the airport operator should install Runway Threshold Identification Lights. - They consist of a pair of white flashing lights installed on either side of the runway threshold. #### Runway Edge Lights - When a runway is intended for night operations, edge lighting must be installed so that pilots can see the lateral limits of the runway. - They consist of fixed white lights, spaced no more than 60 meters apart for instrument runways and no more than 100 meters apart for a non-instrument runway. #### Runway Threshold Lights - With runway edge lighting comes the need to show the exact location of the beginning of the runway, while approaching it. - This is achieved by placing a row of green lights on the threshold. #### Runway End Lights - In order to complete the visual delineation of a runway for night use, it is necessary to install a row of red lights at the far end of the runway. - They indicate where the runway pavement ends. #### Runway Centre Line Lights - For low visibility conditions (Category II and III approaches), it is necessary to provide pilots with an illuminated centerline. - It consists of white recessed fixed lights, installed flush with the pavement between 7.5 and 30 m apart along the whole length of the runway centerline. - Towards the end of the runway, these lights are then alternated red and white, and finally all red to indicate that the aircraft is approaching the end of the runway. - They serve the same purpose as the painted center line markings. #### Runway Touchdown Lights - Under the same conditions, it is required to install a number of transverse bars on the first 900 m of the runway. - In very low visibility conditions, they provide pilots with the location of the touch down area. #### Taxiway Edge Lights - Similar to runways, taxiways intended to be used at night must be equipped with lights delineating the lateral boundaries of the pavement. - They consist of fixed blue lights spaced no more than 60 m, closer in turns. #### Taxiway Centre Line Lights - When a taxiway is intended to be used in low visibility conditions, there is a requirement to install fixed green lights along its center line, no more than 30 m apart. - In this case, it is not necessary to install blue edge lighting. - Taxiway Centre Line Lights in modern airports can often be used as aircraft guidance by directing the pilot to “follow the greens”. - The lights then are switched on and off in segments to guide the pilot to the aircraft stand or to the runway. #### Runway-holding Position Lights - To complement the Runway-holding position markings runway guard lights should be installed on each side of the above-mentioned markings. - They consist of dual alternatively illuminated yellow lights, placed on both sides of the taxiway. #### Stop-bars - Red lights placed perpendicular to the taxiway center line. - No aircraft may cross an illuminated stop-bar. - Stop bars can be placed on any taxiway at any position where it is required that aircraft stop even without an explicit command from the air traffic controller. - Stop-bars are also placed to supplement the runway-holding position markings. #### Runway Status Lights (RWSL) - An automatic system that uses lights to warn pilots of the impending danger of a runway incursion. #### Visual Docking Guidance and Control System - There are various systems in operation that guide the pilot to the appropriate parking position on the stand. - This is critical to enable proper docking of the passenger loading bridge(s), attach the electrical ground power supply or access the hatch for refueling the aircraft. - The aircraft is guided laterally and in distance towards the stop. - Various types of measuring devices recognize the aircraft and signal the appropriate correction information. #### Apron Floodlighting - Although this is not an aerodrome visual aid per se, it is important to adequately illuminate aprons, which are intended to be used at night. - It allows for the safe servicing of aircraft. - It usually consists of bright spotlights mounted on top of high posts, that should not blind the pilot when approaching the aircraft stand. #### Signs - Another type of visual aid found on aerodromes is signs. - They are useful to provide pilots with information and they reduce the amount of radio communications between the control tower and pilots who are not familiar with the aerodrome. - There are three types of signs: mandatory instructions, directional information, and location signs. ###### Sign Design - Signs must be of standard shape and design. - They consist of a rectangular panel, placed vertically. - Signs intended to be used at night or during conditions of low visibility must be illuminated. - All aerodrome signs within a defined area around the runway must be frangible so that, if an aircraft hits them, no damage will occur to the aircraft. ###### Mandatory Instructions - These signs are used when the unauthorized access by an aircraft may jeopardize safety. - For example, entry into a prohibited area or beyond an ILS holding point. - The most common mandatory signs are: STOP, NO ENTRY, CAT I, CAT II, and CAT III. - All mandatory signs consist of an inscription in white on a red background. ###### Directional Signs - Provide information on the direction to take to reach a certain destination on the aerodrome. - They consist of an inscription in black on a yellow background, with an arrow pointing in the direction of the destination point. - The most common directional signs show direction towards a runway a taxiway, or an apron. ###### Location Signs: Provide confirmation to pilots about their location. - They consist of an inscription in yellow on a black background. - The most common location signs indicate the taxiway you are on. #### Markers - When the surface of a runway or a taxiway is not paved, the lack of contrast of the ground may make it difficult to determine the boundaries of the usable surface. - In this case, it is appropriate to install markers. - They consist of flat or conical panels painted red or orange. ### 2.1.1.2.2: Visual Aids for Denoting Obstacles - When obstacles located on or near an aerodrome are likely to constitute a hazard to aircraft, these obstacles must be marked and, if the aerodrome is intended to be used at night, lighted. - The most common obstacles are: tall buildings, communication towers, chimneys, water towers, overhead wires, trees, high terrain, and vehicles. - More on the subject of obstacles is discussed in chapter 2.1.4.5, "Obstacle Restriction and Removal". ###### Obstacle Marking - When feasible, these obstacles are marked with a checkered pattern of orange and white, or red and white. - Vehicles operated on an aerodrome should be marked with a single conspicuous color such as red or yellow. - When lighting is required, various combinations of colors and locations are provided. - These combinations are: fixed red, flashing red, or flashing white. - Lights installed on vehicles should be flashing red or yellow. ### 2.1.1.2.3: Visual Aids for Denoting Restricted Use Areas - There are several reasons why an aerodrome area can be restricted to aircraft: - The area is closed for construction, maintenance, or has been decommissioned. - The area cannot bear the weight of an aircraft, such as the shoulder of a taxiway. - A permanently closed area is identified by day with markings in the form of a cross. - If night use if intended, unserviceability lights must be used. - These lights must be fixed red or flashing red or yellow. - Additionally, physical barriers should prevent pilots from entering a restricted area in error. - More on this subject is discussed in Chapter 3.3, "Safety Plans During Maintenance and Construction". ###### Temporarily Closed Runway - If an area is closed but it is still possible to bypass it, markers in the form of flags or cones will be used. - When areas adjacent to a taxiway or apron are not designed for use by aircraft and if these surfaces are not readily identifiable, markings in the form of a pair of solid lines must be implemented. ## 2.1.1.3: Electronic Aids - Electronic aids provide pilots with visual reference during the last seconds of flight, immediately prior to landing. - There are other systems that bring the aircraft from a point located several kilometers from the aerodrome to a point aligned with the landing runway, at an altitude where the pilot can visually complete a landing. - Several systems exist to that effect. - The three most widely used systems are: - The Instrument Landing System (ILS), a precision approach. - The Very High Frequency Omni-directional Range (VOR), a non-precision approach. - The Non-Directional Beacon (NDB), a non-precision approach. - The Global Satellite Navigation System (GNSS), both non-precision and precision approaches. ### 2.1.1.3.1: Approach Aids - A precision approach is one executed with lateral and vertical guidance, while a non-precision approach is executed with lateral guidance only. #### Instrument Landing System (ILS) - The ILS provides pilots with guidance through two thin radio beams and two distance beacons. - The two beams intersect each other, and when approaching along the intersection of these two beams, an aircraft is perfectly aligned with the extended centerline of the runway and on the right descent slope. ##### Localizer - A radio transmitter providing lateral guidance generates the first beam. - The localizer is located on the opposite end of the runway seen from the approach side, on the extended centerline, approximately 335 m beyond the runway threshold. - This beam activates an instrument in the aircraft that contains a vertical needle sensitive to deviations from the localizer beam. - By observing this needle, the pilot can determine whether the aircraft is flying along the extended centerline of the runway. - If not, the needle will indicate which way the aircraft must be moved to return to the centerline. ##### Glide Path - The second beam provides vertical guidance. - The glide path transmitter is located on the side of the runway, approximately 120 to 150 m from the runway centerline and 320 m past the threshold. - This beam activates a horizontal needle sensitive to deviations from the glide path beam. - By observing this needle, the pilot can determine whether the aircraft is flying along a predetermined 3-degree slope leading to the runway. - If not, the needle will tell the pilot which way the slope is located, up or down. - The rate of descent can then be adjusted accordingly. #### Distance Measuring Equipment (DME) - By keeping both needles centered, the pilot can guide the aircraft down to a point where approach and landing can be continued by visual reference to the ground or to approach or touch down lights. - Distance information, how far the aircraft is from the runway, is provided by marker beacons. - Marker beacons shoot a signal upward. - As the descending aircraft passes though these narrow vertical beams, a light will flash on the instrument panel and an audio signal will sound. - Each marker beacon emits on a different frequency and will trigger a different light signal in the cockpit. - The distance between the runway and each marker being precisely known, the pilot can then determine the aircraft’s exact distance from the runway. - DME, collocated with an ILS, provides the pilot with continuous distance information. #### Categories of ILS - The glide slope originates near the touchdown zone. - This is the area where a landing aircraft makes contact with the runway. - When conducting an ILS approach, the pilot must make a transition from relying on onboard instruments to follow a proper trajectory to using visual reference to the ground in order to land the aircraft, with the aid of runway lights and markings. - This transition requires a minimum cloud ceiling height and visibility. - There is a minimum height (the decision height) to which a pilot can safely descend and a minimum visibility to carry out this transition. - A commercial jet aircraft approaches at a speed in excess of 120 knots which translates in 60 m per second. ###### Minimums - ICAO promulgated three categories of ILS based on their capability to bring aircraft down to specific minima. - Category III c approaches do not require any visibility or ceiling height. - A Cat III c approach can only be accomplished by adequately equipped aircraft and qualified pilots. | ILS Category | Decision Height | Visibility | |---|---|---| | CAT I | 60 m | 800 m | | CAT II | 30 m | 400 m | | CAT III a | 0 m | 200 m | | CAT III b| 0 m | 50 m | | CAT III c| 0 m| 0 m| #### Very High Frequency Omni-directional Range (VOR) Approach - The VOR approach brings the aircraft down to minima in the order of a 150 m ceiling and a visibility of 2.5 km. - VORs are often located several kilometers from the aerodrome and they often serve the dual function of approach aid and enroute navigational aid. - VORs tell the pilot, in which compass-direction the aircraft must fly to reach the position of this navigation aid. - For example, 78 degrees towards the VOR and 258 degrees flying from the VOR degrees. #### Non-Directional Beacon (NDB) Approach - Similar to VORs, NDBs often serve as approach and enroute functions. - NDBs just send out a neutral signal, on which the pilot can identify the general direction towards the NDB. - It does NOT send out any compass-information. - The pilot will fly towards NDB "GL" on compass direction 77 degrees. #### Global Satellite Navigation System (GNSS) Approach - GNSS is providing both non-precision and precision approaches at many airports of the world. - GNSS has the advantage of not relying on ground-based navigation aids, except for the correction signals that need to be transmitted for some systems from a ground station. - GNSS uses the signals emitted by several satellites to determine the three-dimensional position of the aircraft. - The information can be used to conduct approaches with minima comparable to those provided by the VOR and ILS. - GNSS allows airports with limited approach aids to afford the level of service provided by traditional electronic aids, without the complication and cost of their installation. ### 2.1.1.3.2: Surveillance - Air traffic controllers follow traffic on and in the vicinity of the airport using various surveillance technologies. - Aircraft in the air are followed using traditional radar. - Primary radar, where the traffic display is generated using the signals reflected from the aircraft is usually supplemented by secondary radar. - In this more capable solution, the traffic display is generated using the replies from a transponder on board the aircraft, sent in response to an interrogation from the ground system. - Secondary radar can also provide altitude information. #### ASDE - A special radar called Airport Surface Movement Detection Equipment (ASDE) is used to track aircraft on the ground. - ASDE has a much higher update rate than radars used to follow aircraft in the air. - It can provide a very accurate and detailed picture of everything moving around the airport. #### Multilateration - This system calculates the position of aircraft and suitably equipped vehicles on the ground by calculating the time it takes for the transponder response to reach a number of antennas, placed at and around the airport. This system is very accurate. - It gives good coverage everywhere on the airport if antennas are well placed. - Its price is a fraction of traditional radar systems. #### Automatic Dependent Surveillance-Broadcast (ADS-B) - The most common version uses a modified form of the secondary transponder message. - The extended message carries the position of the aircraft as determined by the GNSS receiver on board the aircraft. - This system can replace traditional radars. - The price is much lower than traditional radars. - Although primarily used for surveillance of aircraft in the air, it is perfectly usable for ground surveillance also. ###### The Air Traffic Controller’s View - Whichever technology is used for acquiring aircraft position, the picture the air traffic controller actually sees is a digitally enhanced version of the situation. - This improves accuracy and reliability as well as improving the information richness of the display. - This means that alongside traffic, other information can also be presented. - This may include, but is not limited to, cleared taxi paths, status of ground lights, closed areas, etc. ## 2.1.1.4: Communication Aids - Aeronautical communications are the main tools used to establish clear and efficient communication between pilots and air traffic controllers. - Aeronautical communications are essential to the rapid and efficient exchange of information between different organizations and their people. - There are three types of communication services: - Fixed Services - Mobile Services - Portable Services ### 2.1.1.4.1: Fixed Services - Fixed services are used to transmit information between two or more organizations such as airports, airlines, and ATC units. - They rely on cable or radio technology. - Examples of messages transmitted over this type of service are Flight Plans, weather observations and forecasts, and other messages related to the safety and progress of flights. ### 2.1.1.4.2: Mobile Services - Mobile services rely on radio technology to send and receive voice messages. - In spite of their name, they consist of a fixed and a mobile station. - They are the most common example of air-ground communications used by ATS units to provide pilots with instructions and information. - This technology uses Very High Frequencies (VHF). - Airlines also use this type of service to communicate with their own aircraft for reasons such as estimated time of arrival, aircraft serviceability, and other operational reasons. - Airport personnel use this communication when inspecting active runways. - Any user of such aeronautical radio communication must have a proper training and license. ### 2.1.1.4.3: Portable Services - Portable services are extensively used by airport personnel to exchange operational information relative to emergencies or routine maintenance. - They use small radio transmitters and receivers commonly called "Walkie-Talkies". - They operate on Ultra High Frequencies (UHF). - Users include police forces, security personnel, and airport maintenance employees. - Modern technology (digital trunk radio) allows for clustering and channeling such radio communication thus reducing the acoustic-/voice load on the transmitting frequencies. # 2.1.2: Airside Partners - The smooth and efficient operation of the airport is dependent on the good cooperation of the airside partners. - Those partners belong to different organizations, most of them profit oriented, with different corporate priorities, which must nevertheless be oriented towards the common goal: provide the safest, best service to the passengers. - Partners include: - Airport operator: The operator of the airport may or may not be the same organization as the owner of the facility. - Owners could include a local municipality or the national government. - They often sublet the operation to a specialized company. - If the owner is a municipality, an efficient airport may be part of their overall plan to improve the lives of their city or town. - Specialized companies may be from another part of the world. - For them, the primary consideration is safety and a healthy profit. - Airports in relatively close proximity to each other also tend to compete, especially if there is a high-speed rail network that can bring passengers to and from the catchment area of one to the other. - Finally, the airport operator is the "boss" of all the other partners doing business at the facility and they set the rules and conditions. - The airport operator is also responsible at certain airports for the management of the aprons and as such arranging the movement of aircraft on those areas. - Aircraft operators: They are the reason for the existence of airports. - The service the airport provides to the passengers of the aircraft operators determines to a very large extent the picture passengers will have of the aircraft operators themselves. - It is difficult to remedy the impression a crowded, uncomfortable airport leaves on a passenger even on a longer flight. - So, while airports try to attract airlines/aircraft operators, they are also picky if there are alternatives with better or worse service. - Aircraft operators pay for the privilege of using the airport and as clients are well placed to demand high quality service. - The relationship between the aircraft operator and the airport operator is the classic seller and buyer setup: the aircraft operator wants the best possible service at the lowest possible price while the airport operators want to sell as much as possible of the service that he can provide. - The gap between what is being offered and what is demanded can sometimes open substantially. - Ground service providers (GSP): Aircraft on the ground between two flights or for other reasons need all kinds of attention. - GSPs are the organizations which provide direct support to the aircraft, passengers and cargo. - They are the