NATS Test PDF

Air Traffic Control for Candidates at Initial Test Stage Welcome to the NATS guideline document to Air Traffic Control. This online document should provide the foundation for your ATC studies when attending the initial ATCO recruitment...

Air Traffic Control for Candidates at Initial Test Stage Welcome to the NATS guideline document to Air Traffic Control. This online document should provide the foundation for your ATC studies when attending the initial ATCO recruitment tests with NATS. You will be tested on the content of this document throughout the application process therefore it can not be stressed enough how important it is for you to learn the information enclosed. Introduction Air Traffic Control in the UK Aerodrome Controller Approach Controller Area Controllers Controlled Airspace Uncontrolled Airspace Air Traffic Control over the Atlantic Oceanic Control Tracks and Separations Separation New Technologies and Future Concepts Mode S Time Based Separation SESAR Radar, Primary Radar, Secondary Radar Air Traffic Control for Candidates at Initial Test Stage 1  Navigational Aids The Aircraft That Use The System Extra Content and Notes Air Traffic Control for Candidates at Initial Test Stage 2  Air Traffic Control in the UK Original Summary Airspace over the UK is divided into two Flight Flight Information Regions (FIRs), called London and Op Information Coverage Area Control Center Ma Scottish. Region (FIR) The London FIR covers the majority of England Majority of London Area LA and Wales and is controlled by the London Area London FIR England and Control Centre, Mi Control Centre at Swanwick in Hampshire. The Wales Swanwick Centre started operating in January 2002, and the Scotland, operations room in Swanwick contains: Northern Scottish En- MA Scottish FIR Ireland, Route Centre, London Area Control Centre (LACC), which OA surrounding Prestwick manages en route traffic in the London Flight areas Information Region. This includes en route airspace over England and Wales up to the London Area Control Centre (Swanwick) Scottish border. London Area Control Centre (LACC): London Terminal Control Centre (LTCC), which Manages en route traffic in the London FIR. handles traffic below 24,500 feet flying to or London Terminal Control Centre (LTCC): from London’s airports. This area, one of the Handles traffic below 24,500 feet flying busiest in Europe, extends south and east to to/from London’s airports. the borders of France and the Netherlands, west towards Bristol and north to near Military Air Traffic Control: Services to civil Birmingham. and military aircraft outside controlled airspace. Military Air Traffic Control. Military controllers provide services to civil and military aircraft Scottish En-Route Centre (Prestwick) operating outside controlled airspace. They Manchester Area Control Centre (MACC): work closely with civilian controllers to ensure Controls aircraft over the north of England, safe co-ordination of traffic. Midlands, north Wales (2,500-28,500 feet). Scottish Area Control Centre (ScACC): Controls aircraft over Scotland, Northern Ireland, Northern England, North Sea (2,500- 66,000 feet). Oceanic Area Control Centre (OACC): Controls airspace over the eastern half of the North Atlantic. Responsibilities of Air Traffic Controllers (ATCOs) Preventing collisions between aircraft in the air. Assisting in preventing collisions on the apron and manoeuvring area. Expediting and maintaining an orderly flow of air traffic. Air Traffic Control in the UK 1  Communication and Coordination Controllers use flight progress strips (electronic/paper) with radar to monitor aircraft. Communication with pilots via VHF radio; instructions must be read back. Coordination with adjacent sectors and international centers (Dublin, Shannon, Brest, Paris, Brussels, Maastricht, Copenhagen). NATS Responsibilities Provides air traffic services under competitive contracts. Manages airspace above the UK and into the North Atlantic. Operations room at Swanwick. The Scottish FIR, which covers the whole of Scotland and Northern Ireland and the immediate surrounding areas, is controlled by the Scottish En-Route centre at Prestwick. The operations room in Prestwick contains: Manchester Area Control Centre (MACC), which controls aircraft over much of the north of England, the Midlands and north Wales from 2,500 feet up to 28,500 feet. Scottish Area Control Centre (ScACC), which controls aircraft over Scotland, Northern Ireland, Northern England and the North Sea from 2,500 feet up to 66,000 feet. Oceanic Area Control Centre (OACC), which controls the airspace over the eastern half of the North Atlantic from the Azores (45 degrees north) to a boundary with Iceland (61 degrees north). Air Traffic Control in the UK 2  Operations room at Prestwick. Air Traffic Control in the UK 3  UK Airways Structure NATS is responsible for providing air traffic services under competitive contracts to a variety of airfields in the United Kingdom as well as the airspace above the UK and into the North Atlantic. Air Traffic Control in the UK 4  Some of NATS’ airfield customers Air Traffic Controllers (ATCOs) are responsible for the safe, orderly and efficient movement of aircraft from the moment it leaves the departure gate to the aircraft arriving at its gate at its destination. Whether controllers are working in a control tower or an area centre the role will incorporate one or more of the following responsibilities: Preventing collisions between aircraft in the air. Assisting in preventing collisions between aircraft moving on the apron and the manoeuvring area. Assisting in preventing collisions between aircraft and obstructions on the manoeuvring area. Expediting and maintaining an orderly flow of air traffic. Air Traffic Control in the UK 5  Controllers are provided with details of any flight that intends to fly through the airspace they are responsible for, or any flight that is due to arrive/depart from an aerodrome. The callsign, route, altitude and speed of the intended flight are, amongst other details displayed on an electronic or paper flight progress strip which is generated by the ATC computers when a flight plan is filed. These details help the controllers plan for the aircraft and to solve any potential conflictions. The Controllers use the paper or electronic flight progress strips in conjunction with radar and other displays to monitor the progress of the aircraft, either on the surface of the airport or in the proximity of the airfield or through an en- route sector. Controllers and pilots communicate using VHF radio and any instruction that the Controller issues to an aircraft must be read back by the pilot. Controllers must communicate with each other to pass details of flights as they move from one sector to another. Often the information is passed by a computer link but controllers also use telephones to communicate with these adjacent centres. This rule also applies if the next sector is one inside an adjacent centre’s airspace. The UK must co-ordinate with Air Traffic Control Centres in Dublin, Shannon, Brest, Paris, Brussels, Maastricht and Copenhagen. Likewise, these adjacent centres must inform the UK about flights approaching UK airspace. Air Traffic Control in the UK 6  Aerodrome Controller Original Summary The Aerodrome Controller is The Aerodrome Controller is responsible for the safety and responsible for the safety and movement of the aircraft on the movement of aircraft on the airfield, airfield from the time it pushes back including issuing instructions for from stand, to departing and vice taxiing, takeoff, and landing. Wind versa. The aerodrome controller will conditions influence runway use and issue instructions for the aircraft to flight directions. Tower controllers taxi to and from the runway as well also manage vehicle movements on as clearances to take off and land. the airfield. In busier airports, tasks The runway in use and direction of are divided among controllers, arrivals and departures will be focusing on either runway-specific dependant on the wind conditions; tasks ('AIR') or ground movement aircraft prefer to land and depart into ('GROUND'). wind. In addition, tower controllers will also Responsibilities issue routings and clearances to the Task Description aircraft prior to departure and ensure the safe movement of all vehicles Safety and movement Aircraft of aircraft from stand that are moving around the airfield. Movement to departure and vice At busier units, the task of a tower versa controller may be split between a Issuing taxi, takeoff, Runway number of controllers who will take and landing Instructions elements of the task to focus on. In clearances general terms, it is split between Adjusting runway use runway specific tasks (commonly Wind Condition and flight direction referred to as ‘AIR’) and movement Management based on wind between the stands and the runway conditions vicinity (commonly referred to as a Ensuring safe Vehicle ‘GROUND’). movement of vehicles Movement around the airfield Departure Issuing routings and Clearances clearances prior to Aerodrome Controller 1  departure Divided between Task Division runway tasks ('AIR') (Busy Units) and ground movement ('GROUND') Task Division (Busy Units) Focus Area Tasks AIR Runway-specific tasks Movement between GROUND stands and the runway vicinity Aerodrome Controller 2  View from Heathrow Visual Control Room Aerodrome Controller 3  Approach Controller Original Summary Approach Controllers take over from Approach Controllers manage aircraft the area controllers as the aircraft is as they approach an airport and approaching the airport. They give sequence them for landing. They may the initial clearance for the aircraft to also handle the initial phase of flight approach the airport and put all after departure and any transiting approaching aircraft into a sequence flights in the immediate airspace. to create the most efficient order for Using radar, they provide headings, landing. They will also be responsible altitudes, and speeds to guide aircraft in some cases for the initial phase of to the final approach path. Spacing flight after the aircraft departs an between aircraft is determined by aerodrome before being transferred factors such as weather, aircraft size, to area control, and any other flights and wake turbulence. Major airfields transiting the immediate airspace have holding facilities called "stacks" surrounding the aerodrome. for expected delays. Approach The Approach Controller, if using Controllers are often based at the airfield but can also operate from radar, will issue the aircraft with headings, altitudes, speeds and any remote locations like Swanwick. Control is transferred to the other relevant information to guide it Aerodrome Controller when the towards the final approach path for the runway in use. aircraft is 6 - 12 miles from the runway. The spacing between aircraft depends on a number of factors, Important Information such as the prevailing weather conditions, the size of the aircraft Factor Details involved and the number of aircraft Approach Controllers waiting to depart. Larger aircraft provide initial create more wake turbulence than Clearance and approach clearance sequencing smaller aircraft and Approach and sequence aircraft Controllers must provide the correct for landing. turbulence wake separation between Guidance Issue headings, aircraft on the final approach track. altitudes, speeds, and For example, a Boeing 737, which is Approach Controller 1  in the medium wake turbulence relevant information category, must approach the airport using radar. 5 miles behind a Boeing 747, which is Weather, aircraft size, Spacing classed in the heavy wake turbulence and number of factors category. However, if the 747 were to departing aircraft. follow the 737, a distance of only 3 Medium behind Wake miles would be required. heavy: 5 miles turbulence Heavy behind At major airfields there are holding separation medium: 3 miles facilities called “stacks”, which Holding aircraft may be required to enter if a Heathrow: 4 stacks facilities delay is expected. As examples, Gatwick: 2 stacks ("stacks") Heathrow and Gatwick have 4 and 2 Often at the airfield, stacks respectively. but also from Terminal Controller Approach Controllers are often based Control Operations at locations at the airfield for which they provide Swanwick for London airports. the service, although NATS provides the approach function for the London Transfer to When aircraft is 6 - 12 Aerodrome airports from the Terminal Control miles from runway. Controller Operations room at Swanwick. When the aircraft is established on the final approach at between 6 - 12 miles from the runway, the Approach Controller will transfer control of the aircraft to the Aerodrome Controller. Approach Controller 2  Area Controllers Original Summary Area Controllers are responsible for the Area Controllers manage aircraft during aircraft in the climb, descent and en-route the climb, descent, and en-route phases phase of the flight. of flight, ensuring safe and efficient Area Controllers will issue levels, headings routing. They coordinate with different and speeds to separate aircraft to provide sectors/controllers as aircraft move the most safe and expeditious routing to through various airspace sectors. There the exit point. Agreement with the next are two main categories of airspace within sector/controller along the entire route of Flight Information Regions (FIRs): the aircraft is a major function of the role controlled and uncontrolled. The and each aircraft will be transferred along classification of airspace (A, C, D, E for controlled and G for uncontrolled) dictates the line according to set conditions every time it leaves and enters a new sector. the flight rules and minimum services provided. Summary Tables Responsibilities of Area Controllers Responsibility Description Manage climb, Ensure safe and descent, and expeditious routing to the en-route phases exit point Issue levels, headings, and Separate aircraft speeds Coordinate with Transfer aircraft according next to set conditions when sector/controller entering/leaving a sector Categories of Airspace Classes of Category Description Airspace Specific flig rules and Controlled A, C, D, E minimum services Area Controllers 1  Outside Uncontrolled G controlled airspace Within the FIRs there are two main categories of airspace - ‘controlled’ and ‘uncontrolled’. The classification of the airspace within a FIR determines the flight rules which apply, the minimum services which are to be provided and are generically termed controlled and uncontrolled airspace. There are presently five classes of airspace in the UK, classes A, C, D and E are classes of controlled airspace and class G is outside controlled airspace. Area Controllers 2  Controlled Airspace Original Summary Controlled airspace is provided primarily to protect Controlled airspace is designed to protect its its users, mostly commercial airliners, and as users, mainly commercial airliners. Aircraft such, aircraft which fly in controlled airspace must operating within this airspace must meet specific be equipped to a certain standard and their pilots equipment standards, and pilots must have the must hold the necessary qualifications. Pilots must necessary qualifications. Entry into controlled obtain a clearance from Air Traffic Control to enter airspace requires clearance from Air Traffic such airspace and, except in an emergency Control (ATC) and compliance with ATC situation, they must follow ATC instructions instructions. implicitly. Classes of Airspace In class A airspace, only Instrument Flight Rules (IFR) flight is permitted. It is the most strictly Permitted Class Requirements No regulated airspace where pilots must comply with Flights ATC instructions at all times. Aircraft are separated ATC clearance Ma from all other traffic and the users of this airspace and strict an are mainly major airlines and business jets. A IFR only compliance jet with ATC Class C airspace in the UK extends from Flight thi instructions Level (FL) 195 to FL 660. Both IFR and Visual Flight ATC clearance Rules (VFR) traffic operates and requires a Ex and compliance clearance to enter the airspace and compliance C IFR, VFR FL with ATC with ATC instructions are mandatory. 66 instructions Class D airspace is for IFR and VFR use; an ATC ATC clearance Sp clearance is needed and compliance with ATC and compliance D IFR, VFR 25 instructions is mandatory. Control areas around with ATC be aerodromes are class D and in class D airspace, a instructions speed limit of 250 knots applies if the aircraft is IFR requires Co below FL 100. E IFR, VFR ATC clearance; ma VFR does not IFR Class E airspace is for IFR and VFR use. IFR traffic requires an ATC clearance and compliance with Types of Controlled Airspace ATC instructions is mandatory for separation purposes. VFR traffic does not require a clearance Type Description to enter class E airspace. Aerodrome Protects aircraft near aerodromes Controlled airspace is also divided by type Control Zones depending on where it is and the function it Above Aerodrome Traffic Zone provides. Control Areas (ATZ), extends to a specified upper limit Aerodrome Control Zones afford protection to Established at airways junctions near aircraft within the immediate vicinity of Terminal major aerodromes, e.g., London aerodromes. Control Areas Terminal Control Area Control Areas are situated above the Aerodrome Corridors connecting Terminal Traffic Zone (ATZ) and afford protection over a Control Areas, typically 10 miles Airways larger area to a specified upper limit. wide, bases between 5000 to 7000 ft and up to 24,500 feet Terminal Control Areas are normally established at the junction of airways in the vicinity of one or Upper Air Above airways, usually from FL 250 Routes (UARs) to FL 460, mandatory ATC service Controlled Airspace 1  more major aerodromes. for civil and military above FL245 The London Terminal Control Area is an example of this and deals with air traffic arriving and London Terminal Control Area departing from London Heathrow, Gatwick, Luton, Handles traffic for London Heathrow, Gatwick, Stansted, London City, Northolt, Biggin Hill, Luton, Stansted, London City, Northolt, Biggin Southend, Farnborough and other minor airfields Hill, Southend, Farnborough, and other minor in the London area. airfields in the London area. Airways are corridors of airspace connecting the Terminal Control Areas and link up with airways in other countries too. Airways are normally 10 miles wide and have bases between 5,000 feet and 7,000 feet and they extend upward to a height of 24,500 feet. Upper air routes (UARs) sit above airways. Their vertical limits are usually FL 250-FL 460. Civil and military aircraft operating above FL245 are subject to a full and mandatory Air Traffic Control Service. Controlled Airspace 2 Controlled Airspace 3 Controlled Airspace 4  Uncontrolled Airspace Original Summary Within class G airspace aircraft may Aircraft in class G airspace can fly fly when and where they like, subject freely, following simple rules, and are to a set of simple rules. Although responsible for their own safety, there is no legal requirement to do though they can notify Air Traffic so, many pilots notify Air Traffic Control (ATC) and seek assistance. Control of their presence and Various services offer different levels intentions and pilots take full of protection and information: responsibility for their own safety, although they can ask for help. Available Services The following services are available Service Description and offer varying degrees of Deconfliction Provides advice to protection and/ or information for the Service avoid other aircraft pilot. However, the avoidance of Offers traffic other aircraft remains the pilot’s Traffic Service information to the responsibility. pilot Deconfliction Service Supplies basic Basic Service information and Traffic Service assistance Basic Service Two other types of service pilots can Additional Services Outside receive outside controlled airspace Controlled Airspace are an Alerting Service and a Service Description Procedural Service. An Alerting Notifies organizations Service is provided to notify for search and rescue appropriate organisations regarding Alerting Service aid and offers aircraft in need of search and rescue assistance as aid and assist such organisations as required required. A Procedural Service is a Procedural Non-radar-based non radar-based service in which Service service providing deconfliction advice is provided deconfliction advice against other aircraft receiving a against other aircraft Uncontrolled Airspace 1  Procedural Service from the same under the same controller. controller Uncontrolled Airspace 2  Air Traffic Control over the Atlantic Original Summary Shanwick Oceanic Control Area The Shanwick Oceanic Control Area, (based at Prestwick) has based at Prestwick, manages air responsibility for air traffic control traffic control over the North Atlantic, over the North Atlantic, which is a responsibility shared with the UK, shared by the UK, Portugal, the USA, Portugal, the USA, Canada, and Canada and Iceland. NATS is Iceland. NATS oversees the Eastern responsible for the Eastern portion of Atlantic from latitudes 45°N to 61°N the Atlantic which stretches between and longitudes westward to 30°W. latitudes 45 degrees North and 61 Communication is maintained via HF degrees North and westward to radio from Shannon, Eire, with pilots longitude 30 degrees West. Voice reporting positions every 10 degrees communication is maintained through of longitude. HF (High Frequency) radio, which is Every 12 hours, organized tracks are based at Shannon in the west of Eire. created to optimize aircraft routes. A pilot makes position reports usually Prestwick OACC handles westbound every 10 degrees of longitude. tracks, while Gander OACC in A system of organised tracks is Canada manages eastbound tracks. constructed by the relevant OACC Tailwinds are considered to enhance every 12 hours to accommodate as fuel efficiency and reduce travel time. many aircraft as possible on their Ocean crossing clearances specify most economic flight path. Prestwick track, flight level, speed, and entry OACC is responsible for the time restrictions. Planners coordinate westbound track system (usually across the ocean and with domestic through UK airspace between ATC agencies to meet traffic 1000hrs and 1600hrs) and Gander demands. Modern equipment at OACC, Canada, for the eastbound Prestwick ensures safe conflict track system. When organizing the resolution and clearances. track structure the prevailing wind is taken into account as airlines like to Important Information take advantage of a tailwind, which is Air Traffic Control over the Atlantic 1  more fuel economical and gets the Area Responsibility aircraft and passengers to their North Atlantic air destinations quicker. Shanwick OCA traffic control Clearances to cross the ocean will Eastern Atlantic (45°N NATS include the track, flight level and to 61°N, 30°W) speed, and any time restrictions for Prestwick Westbound track entry on to the track structure will OACC system also be given. Planners on either side Eastbound track Gander OACC of the Ocean consult with each other system and co-ordinate as necessary with adjacent OACCs as well as domestic Communication Details ATC agencies, to ensure the system Voice HF radio based at provides sufficient capacity for the Communication Shannon, Eire anticipated demands. Modern Every 10 degrees of Pilot Reports equipment installed at Prestwick longitude ensures that the Air Traffic Controllers are able to detect and Track Details resolve conflictions on the Oceanic Organization tracks and thus issue safe clearances Frequency Every 12 hours to the participating traffic. Prevailing wind for Considerations fuel efficiency Track, flight level, Clearances speed, entry time Coordination Details Consult and Planners coordinate with OACCs and ATC Modern systems at Equipment Prestwick for conflict resolution Air Traffic Control over the Atlantic 2  Separation Original Summary In controlled airspace each aircraft is separated In controlled airspace, aircraft are separated by from all other aircraft by internationally agreed internationally agreed standards, either by standards. This is achieved by allocating aircraft different heights or minimum horizontal distances. different heights or by issuing headings (vectors) These rules vary based on the location: so that the aircraft can be at the same height but a London Terminal Control Area: Aircraft under minimum horizontal distance apart. radar control must be separated by 3 nautical These rules vary depending on where the aircraft miles horizontally or 1,000 feet vertically if is flying. closer than 3 miles. In the London Terminal Control Area aircraft Outside London Terminal Control: Aircraft operating under radar control must be separated under radar control must be separated by 5 by 3 nautical miles from other aircraft at the same nautical miles horizontally or 1,000 feet height. If they are less than 3 miles apart they vertically up to FL290. Above FL290 to FL410, must be separated by a minimum of 1,000 feet. 1,000 feet vertical separation is maintained Outside of London Terminal Control airspace, under RVSM rules, otherwise 2,000 feet is aircraft operating under radar control must be kept required. 5 nautical miles apart if they are at the same level NATS introduced Reduced Vertical Separation or 1000ft vertically up to FL290. Above this, 1000ft Minima (RVSM), allowing aircraft with accurate vertical separation may continue to be provided altimeters to maintain 1,000 feet separation above up to FL410, subject to aircraft being suitably FL290 and below FL410, increasing airspace equipped to comply with Reduced Vertical capacity. Separation Minima (RVSM) rules, otherwise 2000ft should be applied. Separation Rules NATS was at the forefront of introducing Reduced Vertical Ve Vertical Separation Minima (RVSM). Aircraft that Horizontal Area Separation (up Se have had their altimeters checked to a high degree Separation to FL290) (FL of accuracy and which can comply with other London 1,000 feet (if strict criteria are allowed to fly across the Atlantic Terminal 3 nautical miles closer than 3 - track structure with only 1000 feet separation Control Area miles) above FL 290 and below FL 410. This separation Outside London 1,0 standard allows many more aircraft to fly through Terminal 5 nautical miles 1,000 feet (RV airspace where RVSM is allowed. Control fee RVSM (Reduced Vertical Separation Minima) Vertical Condition Separation FL290 to FL410 (RVSM compliant) 1,000 feet FL290 to FL410 (non-RVSM 2,000 feet compliant) Separation 1  New Technologies and Future Concepts Original Summary A lot of development in aviation is to A significant focus in aviation ensure that either safety is increased development is to enhance safety or that capacity is increased without and increase capacity without safety being compromised. compromising safety. Air Traffic Air Traffic Controllers within LACC Controllers within LACC use a system developed by NATS called IFACTS now use a system developed by (Interim Future Area Control Tools NATS called the Interim Future Area Support), operational since 2012, to Control Tools Support, known as IFACTS. It became operational in meet the projected demand of 3 million annual movements at 2012, helping NATS to meet the projected demand of 3 million annual Swanwick by 2015. movements at Swanwick by 2015. IFACTS Objectives IFACTS has 3 main objectives for NATS: Objective Description Enhance the Increase capacity overall capacity of Increase capacity Eliminate paper flight progress air traffic strips management Eliminate paper Reduce the number of safety Transition to a flight progress significant events digital system strips IFACTS also aims to reduce the Reduce the controller’s workload by equipping Minimize safety- number of safety related incidents them with tools to aid them in significant events medium term confliction resolution. Trajectory prediction will also assist Key Functions of IFACTS the controller by calculating where Function Description the aircraft will be in 18 minutes based on the aircraft’s level, speed and heading. New Technologies and Future Concepts 1  If the controller inputs any tactical Tools to aid Medium term clearances the system updates the controllers in confliction trajectory. Tactical controllers have resolving potential resolution conflicts the use of a separation monitor which helps them monitor the traffic in their Calculates the sector and displays to the controller aircraft's position 18 Trajectory minutes into the the interactions that are predicted to prediction future based on happen within the sector in the next level, speed, and few minutes. heading IFACTS also allows the controller to Helps controllers check what might happen if a monitor sector traffic Separation particular clearance were to be and predict monitor issued to an aircraft. This is called a interactions in the next few minutes tactical what-if and this will superimpose on the radar screen the Allows controllers to predicted trajectories of the aircraft check the potential impact of issuing involved. Tactical what-if clearances by displaying predicted trajectories IFACTS is designed to reduce the workload of controllers by providing advanced tools for conflict resolution and trajectory prediction. It updates trajectories with any tactical clearances input by controllers and includes a separation monitor to oversee sector traffic. The tactical what-if function enables controllers to visualize potential outcomes of clearances on the radar screen. New Technologies and Future Concepts 2  Mode S Original Summary Mode S is a development to supersede the Mode S is an advancement designed to present Mode A and C technology and the replace the current Mode A and C limitations that this system has. At present technologies, addressing their limitations. the radars interrogate the transponders of Current radars interrogate aircraft aircraft and receive the information about transponders to receive information about the aircraft and its height. In areas of high the aircraft and its altitude. In high traffic traffic density, for example in the stacks areas, like around Heathrow, Mode A and around Heathrow, the integrity of the C integrity can be compromised due to mode A and C is sometimes adversely signal garbling. Mode S mitigates these affected by the garbling of all the returns. issues by targeting individual aircraft, Mode S alleviates these shortcomings enhancing radar accuracy. Additionally, because the radar system will, in effect, Mode S allows controllers to view specific target individual aircraft rather than try to information set by pilots, such as Selected attempt to resolve all the replies. Flight Level, Indicated Air Speed, and Mode S provides the controller with the heading, aiding in conformance opportunity to view certain information, monitoring and reducing radio transmissions. e.g. Selected Flight Level/Indicated Air Speed/heading etc., which the pilots have Key Information set in the cockpit to aid with conformance monitoring and reducing RT for both Feature Mode A & C Mode S controller and pilot. General Targets Radar transponder individual Interrogation interrogation aircraft Integrity Alleviates High Traffic affected by signal garbl Areas signal garbling issues Selected Fli Information Aircraft ID and Level, Indic Provided altitude Air Speed, heading, etc Enhanced w Conformance specific Limited Monitoring information from pilots RT (Radio Higher Reduced Transmission) Mode S 1 Mode S 2  Time Based Separation Original Summary In 2015 NATS was the first ANSP to introduce Time Based In 2015, NATS became the first ANSP to implement Time Separation on final approach, having been initially Based Separation (TBS) on final approach, initially at deployed at London Heathrow. London Heathrow. TBS determines the gaps between aircraft based on time rather than distance, considering Instead of the space between aircraft being determined wind conditions and wake turbulence. Stronger winds by distance, as has historically been the case, the gaps disperse vortices faster, allowing aircraft to be positioned between successive aircraft are based on time, taking closer together, thereby increasing the landing rate. into account the prevailing wind and the associated wake turbulence being produced by the aircraft type. Key Information The stronger the wind is, the quicker the vortex that is produced will be dispersed. As the wind speed increases Factors Year Implementation Concept the closer the aircraft can be positioned in trail on final Considere approach, therefore increasing the available landing rate. Wind Time Based London conditions 2015 Separation Heathrow Wake (TBS) turbulence Impact on Aircraft Wind Speed Effect on Vortex Positioning Quicker Closer positioning on Stronger dispersion final approach Time Based Separation 1  SESAR Single European Sky ATM Research (SESAR) is a European wide concept that aims to deliver a restructuring of airspace as a function of flows not borders to allow more direct routing for aircraft and closer integration between ANSPs. This is to enable dynamic airspace management and a more efficient Air Traffic Management capability, ultimately creating additional capacity. SESAR 1  Radar, Primary Radar, Secondary Radar Radar The use of radar, both primary and secondary, assists Air Traffic Controllers in their main task of ensuring safe separation between aircraft. There are radar sites at many airports around the country and at other strategic sites. These radars ensure that the Controllers who work at the various units around the UK receive the best possible picture and information from the radars. Primary Radar Primary radar provides only very basic information about the position of an aircraft in relation to the radar. It will show all aircraft within its coverage and will also show other objects like high terrain, certain weather and possibly large flocks of birds. Secondary Radar Secondary radar is selective, and only displays information from aircraft equipped with a transponder. Before an aircraft departs from an airfield or before it enters the airways systems it is allocated an individual four-digit code, which the pilot dials up in the transponder. When the aircraft gets airborne, or before it enters the airways systems, the ground based radar interrogates the transponder. When it recognises the code, which is allocated to that particular flight, the aircraft’s height information and callsign is displayed to the Controller in the form of a label next to the position of the aircraft. The Controller is also able to display maps of airways and upper air routes as well as coastlines and danger areas on the display. Radar, Primary Radar, Secondary Radar 1  Navigational Aids Original Summary NATS provides and maintains a large NATS provides and maintains a variety of number of navigational aids to enable navigational aids to ensure precise aircraft aircraft to fly the airways systems with the navigation. The VHF Omni-directional necessary accuracy. Range (VOR) is the most accurate ground- The most accurate of the ground based based aid, emitting 360 radial signals for navigational aids is the VHF Omni- navigation. VORs often come with directional Range (VOR) which emits radial Distance Measuring Equipment (DME) to signals which aircraft can fly along. There show how far an aircraft is from the VOR. are 360 radials which an aircraft could fly Non-Directional Beacons (NDB) have a toward or away from a VOR. Each radial shorter range compared to VORs but still assist in navigation. With the increased represents 1 degree from 0-359 degrees reliability of GPS, many ground-based aids VORs often have an associated DME are being phased out. Aircraft use data (Distance Measuring Equipment) with from multiple sources to feed into their them. This shows the pilot how far the Flight Management Systems (FMS), which aircraft is away from the VOR. vary in complexity. Approach controllers Due to their accuracy, VORs can also be use the Instrument Landing System (ILS) used for establishing stacks. Heathrow’s 4 to guide aircraft during landing, providing stacks are established overhead VORs. directional cues. A Non-Directional Beacon (NDB) just emits a signal which the pilot navigates toward. Navigational Aids The range of most NDBs is in the region of Range about 25 nautical miles whereas a VOR Aid Description (nautical has a much greater range in the order of miles) 125 nautical miles. Emits 360 An increasing number of approach and en VOR radial signals 125 route ground based navigation aids are for navigation being phased out as the capability and Measures accuracy of GPS systems available to and DME distance from N/A on aircraft becomes more reliable and the VOR widespread. Emits a signal for navigation, Aircraft will gather data from various NDB shorter range 25 sources, e.g. Navigational Aids, Inertial compared to Navigation Systems, GPS, and the VOR information is then fed into the Flight ILS Ground-based N/A Management System. radio system Navigational Aids 1  Flight management systems can vary in with localiser complexity from the basic heading and and glide path for landing altitude to the systems which can control guidance the aircraft from departure to arrival. Approach Controllers issue instructions to enable the aircraft to intercept the Data Sources for Flight Instrument Landing System (ILS). The ILS Management is a ground-based radio guidance system Source Description which transmits two directional radio Navigational Aids VOR, DME, NDB, ILS beams, the localiser and the glide path. The pilot then receives indications in the Inertial Measures aircraft position cockpit advising if the aircraft needs to fly Navigation and movement Systems up/down or left/right to keep on the correct approach path. The usual descent Provides global GPS positioning path for an ILS is 3 degrees. Integrates data from Flight various sources to Management manage aircraft from System departure to arrival Approach Controllers & ILS System Description Provides directional cues (localiser and glide path) for ILS pilots to maintain correct approach path during landing Typically 3 degrees for Descent Path standard ILS approaches Navigational Aids 2