SubscribeBackground On the 19th of October 2001 SiATM, Sweden, successfully completed the delivery of an ATC Simulator, which allowed the ANS Training Centre in Riga, Latvia to offer advanced training services for air traffic controllers. The ATCSim contract was signed in May 2000.
The roles of ATC simulators
- Training of air traffic control staff:
A crucial aspect with respect to the training of air traffic control staff, is that the theory, on the operational aspects of aircraft movement and control, taught in the classroom, is complemented by practical exercises, undertaken by the trainees, for both illustration of principles, and practice in their application.
An ATC simulator fulfils this requirement, and will prove most effective in the training environment when exhibiting the following characteristics:
1. A simulated, controlled, operational environment, exhibiting a degree of operational realism sufficient for basic training purposes, but which is not necessarily specific to a particular air traffic control centre.
2.The ability to define specific, repeatable training scenarios, of varying degrees of complexity, for the training/practicing of individual/groups of trainee controllers in defined air traffic situations.
3.The ability to playback specific, individual instances of exercises, executed earlier, in order to view/analyse trainee actions/errors/misunderstandings, and advise on their improvement/rectification
The overall level of training will be significantly enhanced if the simulated environment closely reflects the operational characteristics of the control centre in which the trainee will eventually be working. - Experimentation and evaluation:
An air traffic control system will, in general, be subject to various infrastructure/environmental changes during its operational lifetime - these changes may be required for a number of reasons - for example:
1.Changes to the basic airspace infrastructure internal to the FIR
2.Changes to operational procedures
3.Changes to the locally defined airspace infrastructure for an adjoining FIR - for definition of an OLDI partner, for example.
4.Changes of this type are normally sensitive in nature, and may result in system malfunction if not properly validated prior to incorporation in the operational environment.
5.Additionally, temporary, experimental changes (of type ’what if’) may be required, which cannot be tested in the operational system.
Consequently, the availability of an offline environment, for experimentation and evaluation of such intended changes, is highly desirable. An ATC simulator will fulfil this requirement if its simulated environment exactly reflects the operational/environmental characteristics of the control centre in which the changes are to be made.
Training environment
Basic simulator structure.
The simulator system comprises two main components:
- Simulator segment
- Operational segment
Figure 1: ATCSim overview
Simulator segment
The simulator segment is the component, which drives the simulation process by generating input traffic for the operational segment - its primary functions are as follows:
- Overall control of the running of the simulation processing for an exercise - i.e. processing of the exercise related ExePlan to create the appropriate environment for the running of the exercise.
- Generation of Flightplan data which is fed to the operational segment - this is based on the SimPlans included in the exercise.
- Generation of Track data which is fed to the operational segment - this is based on both the SimPlans included in the exercise, which determine intended flight routes, and pilot inputs made during the course of exercise execution.
Operational segment
The operational segment is, in effect, an exact copy of the operational system, which is fed with generated flightplan and track input, based on ExePlan definitions, rather than live data.
Constituent physical components
The basic, simulated functional air traffic control environment comprises the following physical components:
Simulator Server
The server is a separate computer providing the complete, encapsulated functionality of both the simulator and operational ATCSim segments, with the exception of that of the trainee, pilot and supervisor positions.
Workstations
A number of individual workstations are provided - these are effectively identical, in that none possesses an affinity with a particular role, and they may be used as trainee, pilot or supervisor positions, as required. The workstations may be used in any desired combination to provide the roles required for the various simulator sessions executing concurrently - with the basic restriction that a particular workstation may only participate in one session at any one time.
A workstation/controller using the workstation may adopt any of the following roles:
- Exercise supervisor
- Pilot
- Trainee
- Feeder
Exercise supervisor
The functions performed by the exercise supervisor are as follows:
1. Session definition:
A session defines the context within which a series of exercises is to be executed - the primary attribute of this context is the airspace infrastructure to be applied. The Exercise Supervisor has overall control of the simulator for a particular session - a number of exercise supervisors may be logged-in simultaneously, at different workstations, where each controls an individual session.
2. Exercise management:
An exercise defines a particular training scenario to be run under the related session - a maximum of one exercise may exist per session at any one time.
Exercise management comprises the following functions:
- Exercise installation
- Exercise control, comprising: Exercise initiation/resumption; Exercise suspension; Exercise termination; Pilot functionality
In addition to the supervisory functions, the exercise supervisor may act as a pilot within an exercise executing within the related session - refer to section below, which gives an outline of pilot functionality.
Pilot
The Pilot role provides an instructor/experienced air traffic controller with the necessary facilities for controlling the manoeuvres of one or more simulated aircraft during an exercise. In addition, the Pilot supports a voice communication facility, to provide a realistic operational dialogue between himself and the trainee(s) controlling his aircraft. One or more Pilot Positions may exist per exercise.
Trainee
The Trainee role provides a trainee controller with a fully simulated Radar Operator Position. The trainee logs-in to a workstation, with a designated operational role, and performs the necessary controller activities as required by the particular exercise under execution. One or more Trainee roles may exist per exercise.
Feeder
The feeder role provides an instructor/experienced air traffic controller with a fully simulated Radar Operator Position, from which he can provide a trainee position with the necessary supporting dialogue and operational controller functions, within an exercise, for practicing controller operations which involve more than one controller (for example, handover or coordination’s between neighbouring FIRs, or adjacent sectors, within the same FIR, controlled by different controllers).
Feeder roles are optional, within an exercise, dependent upon the requirements of that exercise, but one, or more may exist, if required.
Voice communication system
The voice communication system (VCS) may be considered as a separate physical component, in that each workstation is provided with a headset, comprising earphones and a microphone, for vocal interaction - although the communication mechanism itself is effectuated via software in each of the workstations and the network connecting them.
VCS supports two basic types of connection:
- Radio frequency
- Ground to ground
Training preparation
The various exercise scenarios are prepared by an exercise administrator, who has responsibility for the creation and maintenance of exercise definitions and their constituent components.
The administrator has responsibility for the following exercise related items:
Figure 2: Exercise preparation
Exercises
An exercise is the definition of a complete, self-contained training scenario to be run by the simulator.
The definition, of a particular exercise, is made via a related ExePlan (Exercise Plan), which specifies the following exercise related information:
- The start date and time, to be applied at commencement of execution of the exercise
- The version of the system parameters to be applied when validating and executing the exercise
- Flights to be included in the exercise, as defined in the section below on flight definition.
- Default ATIS data related to the exercise
- Default Wind and Temperature data related to the exercise
A new, or modified, exercise definition is checked for validity against the related version of the system parameters - it may also be previewed, which is a non-interactive viewing of the running of the exercise - this may be run at normal, fast or very fast speeds.
A database of ExePlans is maintained by the Exercise Administrator, which forms the basis for all exercises to be executed under the simulator.
Flights
A flight is defined in terms of a SimPlan (Simulator Flightplan), which comprises the contents of a standard ICAO flightplan, with additional, simulator related information. A database of SimPlans is maintained by the Exercise Administrator, which forms the basis for definition of the flights for the exercise definitions, described above - a particular SimPlan may be used in one or more exercises.
The fundamental difference, between the flightplan definition, in a SimPlan, and the ICAO standard, is that the EOBT specification, in the SimPlan, is specified as a relative time, rather than an absolute clock time - during execution, of a particular exercise, the relative time is applied to the exercise start time, to create an absolute EOBT in the context of that exercise.
Airspace infrastructure
The airspace infrastructure definition specifies all aspects of a particular airspace to be used in a training scenario.
The definition includes the following information:
- Geographical Points, of various categories
- Aerodromes
- ATS Routes
- SIDs
- STARs
- Airspace layout, in terms of 3 dimensional sectors of airspace
Any number of separate airspaces may be defined, where any one particular airspace definition may be utilised by one or more exercises, executed within the context of a session (refer to the section below, describing exercise execution). Each definition is made in the form of a set of system parameters, and constitutes a completely self-contained specification.
Aircraft types and performance categories
An aircraft performance category specifies a set of aircraft related performance characteristics common to all types of aircraft defined as lying within that particular category. Any number of aircraft performance categories may be defined, as determined by the various performance characteristics published by aircraft manufacturers. An aircraft type specifies the symbolic type of an individual aircraft model to be used when defining flightplans (for example, a Boeing 737 may be allocated the symbolic type B737).
Any number of aircraft types may be defined, as determined by the number of aircraft models in existence - the set of defined aircraft types is used to represent the full range of aircraft to be handled by the particular system.
The set of aircraft types is mapped onto the defined aircraft performance categories as a many-one relationship - i.e. a number of different aircraft types may share common performance characteristics. The aircraft types and performance categories are defined as a self-contained set of system parameters.
Training execution
Training configuration:
The basic working execution unit for training purposes is the Training Session.
A training session defines a completely self-contained execution environment, in terms of the defined airspace, and other relevant system parameters, for the exercises, which will be run within it.
A number of concurrent sessions may be started, where each may execute a single exercise at any one time. When logging-in for training purposes, a workstation will identify the session within which it requires to execute. Training sessions are started/controlled/terminated by the Exercise Supervisor.
Figure 3: Exercise installation
Exercise supervision
The Exercise Supervisor logged-in to the related session supports supervision, of individual exercises, - the Exercise Supervisor will provide the following functions:
- Exercise initiation
Selection of the particular exercise (ExePlan), which is to be run - this will invoke the installation and validation of the selected exercise. - Exercise Commencement/Resumption
Commencement/resumption of execution of a successfully installed exercise. - Exercise Suspension
Freezing of execution of an executing exercise. - Exercise Termination
Forced termination of an exercise which is no longer required.
Voice communication system
The voice communication system provides the basis for vocal interaction between selected pairs of trainee and pilot/trainee positions - thus facilitating a realistic operational dialogue between the trainee controller and the pilot(s) of the aircraft, which he is attempting to control.
The navigation function
The navigation function simulates the movement of individual aircraft, based on their respective performance characteristics and exercise related environmental conditions (wind and temperature).
Figure 4: Navigation function
The movement simulation is performed taking into account a number of detailed characteristics with respect to takeoff/climb/descent/turn/landing, which results in an extremely realistic simulation of the behavioural characteristics of the particular aircraft.
Movement simulation, for a particular aircraft, may be performed in one of two ways, viz:
- Automatic
This is based on the intended route, as specified by the flight related SimPlan, including automatic takeoff and/or landing.
- Manual
This is based on Pilot input, against a particular flight, which overrides automatic movement simulation (for example, the aircraft may be instructed to adopt a particular heading).
Once manually controlled movement simulation has been initiated for a flight, which was previously subject to automatic navigation, automatic navigation will be discontinued until specifically reinstated.
Pilot functionality
The simulated air traffic situation displayed to the pilot is similar to the radar display of the trainee.
Figure 5: Pilot display
The status area is shown at the top of the radar window, showing information, such as exercise time, QNH setting, runway in use and simulated radar status. Some of the information (the current range, selected unit system and the label filters) are local to the workstation and can be altered. The rest of the information in the status area is simulated environmental data, in particular ATIS data. If no ATIS data has been received the text “ATIS” will be shown in attention colour.
Pilot labels
The pilot has a number of different labels at his disposal. These labels are:
- The Mini label
- The Standard label
- The Selected and Extended labels and
- The Navigation label
Figure 6: Navigation Label
The Navigation label is not directly connected to an aircraft symbol. It can be placed anywhere within the radar window. One such label exists presenting data corresponding to the currently selected aircraft. The main part of the Navigation label is identical to the extended label but there is additional information. From this label it is possible to change the transponder settings, assign special codes (Hijack, Communication failure and Emergency) and activate the special position indicator (SPI). Related to this is the Fade function which makes the aircraft disappear from the radar screen of the display at the trainee positions.
For arrivals, the Navigation label provides the pilot with an approach switch (automatic adaptation of speed during approach) and the automatic landing (ILS procedure) indicator. The last line of the Navigation label contains a description of the current navigation procedure.
Pilot lists
A number of lists presenting data related to aircraft exist. These are
- Responsibility list:
The responsibility list is displayed in the radar window and details the aircraft for which the pilot is responsible. Some pilot commands can be accessed from this list. For each aircraft, there is an indicator for the presence of reports and as to whether the aircraft requires navigational input from the pilot (Manual navigation).
Figure 7: Responsibility list
- Inbound list
The inbound list provides data regarding inbound traffic. The data is used for coordination.
Figure 8: Inbound list
- Take off list:
Departing aircraft are displayed in the Take off list. The major part of the information comes from the operational segment. In the list the pilot can assign the Mode A code, select runway and SID procedure. There are buttons to start Taxiing and to start Take Off. The take off can be performed completely automatically by the system or manually, which require pilot input. - Report list:
The report list contains reports related to the aircraft under responsibility of the pilot. The reports are either requested by the pilot or generated automatically by the system. Some of the system-generated reports are requesting the pilot to perform a command, for example to start to descend or initiate Take off.
Pilot input
Each pilot is responsible for a number of aircraft. Initially navigation of an aircraft simulation is fully automatic and proceeds according to the information in the SimPlan. By taking control of an aircraft the pilot is able to navigate that aircraft. Typically, the pilot would wish to control the speed and altitude of the aircraft while the main navigation is controlled by the system. However, the pilot is able to control the aircraft in any desired way and also change the route.
Pilot commands can be entered by use of pop-menus or buttons available in the labels and in the aircraft lists. The menus usually appear by clicking with the mouse in the appropriate field. For example, to change the speed, the pilot clicks with the mouse in the speed field of the label to get a menu of possible speed values. Some commands are reached from a pop-up menu called the Aircraft menu.
Figure 9: Aircraft menu
Recording and playback
The recording and playback functions provide the necessary information and facilities for viewing the displayed results of previously executed exercises.
- Recording
During the execution of an exercise, the relevant message traffic, within the operational segment, is recorded on disk, to facilitate the playback of the displays at the trainee position(s) participating in that exercise. - Playback
The playback function uses the recorded information, described in the section above, for a particular exercise, to simulate the original message traffic to the various participating trainee roles - thus reproducing the original displays at the related position(s).
The playback function may be performed at any physical workstation.
Voice recognition
In order to increase the pilot workload capacity a voice recognition system is implemented on trial.
This system identifies commands/clearances given by the trainee to the pilot. The recognized command is prepared and suggested to the pilot who can confirm the command with a minimum of inputs.
Trainee functionality
The facilities and functionality available at the trainee positions are dependent upon the characteristics of the operational environment as supported by the particular operational segment of the simulator.
Summary
A high fidelity simulator is apart from being a necessary tool for advanced training of air traffic controllers also an excellent tool for testing changes and upgrading of the operational system. This is done by creating exercises with different traffic scenario with the possibility to repeat the same exercise identically time after time or to slightly modify the traffic to study the system’s behavior.
