EASN Thematic Structure

A Working Group consisting of NLR, QinetiQ and ONERA constructed the ASTERA taxonomy for aeronautical R&T. This is a hierarchical taxonomy that builds upon existing European structuring efforts, such as the GARTEUR taxonomy and EUROCONTROL's ARDEP taxonomy.

The ASTERA taxonomy has been defined, reviewed and agreed upon by a considerable group of experts from different fields within the European aeronautics community. This has given the taxonomy a strong foundation. Therefore EASN uses and if necessary modifies this taxonomy in order to approach a classification of university activities in the field of aeronautics.

Aircraft Avionics, Systems and Equipment



Contains all sub-domains relating to avionics, cockpit and ATM-related aircraft systems.

1. Cockpit Automation: Cockpit, Cockpit systems, Avionics, GPWS, Cockpit displays, EFIS, Glass cockpit, CMU, ATSU, Communications display, enhanced vision systems, CPDLC display, ACARS interface.Comments: on board avionics systems, pilot HMI, validation of sub systems. Includes GPWS, EFIS, enhanced vision systems, communications displays, radios and airborne radar displays.
2. Airborne Separation Assurance System: Airborne Situation Awareness System, Airborne Separation Assurance System, ASAS Human Machine Interface / procedures, CDTI.Comments: Airborne situation awareness systems, Airborne Separation Assurance Systems, automation of these systems, validation of subsystems. ASAS Human Machine Interface / procedures. Systems for autonomous aircraft operations and to support delegation of separation responsibility.
3. ACAS Automation and Use: TCAS, ACAS, Airborne Collision Avoidance System.Comments: Airborne collision avoidance systems, automation of these systems, validation of subsystems. Includes studies of the operation and use of TCAS, ACAS and their impact on the ATM system.
4. Flight Management Systems: Flight Management Systems, FMS, 3DFMS, 4DFMS, Flight Database. Comments: flight management databases, safety and validation of FMS in relation to the ATM environment.


Cockpit Systems, Visualisation & Display Systems

Aircraft cockpits must evolve, to provide aircrew with access to accurate and timely information through highly capable display systems.

1. Cockpit indicators and gauges.
2. Cockpit switch panels.
3. Cockpit display panels. CRT, flat panel, touch screen, head-up displays.
4. Display issues. readability in different lighting situations, resolution, contrast, viewing angle.
5. Reduction in weight, power and cooling requirements.
6. Increased reliability.
7. Integration with flight management and navigation systems (EFIS, ACARS, ATSU).
8. Glass cockpit.


Navigation / Flight Management / Autoland

Navigation and flight management systems are required to optimise the efficiency of operating aircraft in the ever more densely populated airspace. The objective is for full and permanent automatic approach and landing in all weathers.

1. RF-based aircraft navigation and guidance systems (e.g. VOR, ILS, MLS, LORAN, TACAN, ADF, DME, NDB).
2. Satellite-based aircraft navigation and guidance systems (e.g. GPS, differential GPS, GLONASS).
3. Inertial navigation systems.
4. Digital altitude control systems (radar altimeters etc).
5. System interfaces, data flows and analysis. 3D FMS< 4D FMS, flight database.
6. Inspection, adjustment, performance testing, malfunction analysis and corrective.
7. Automatic landing systems. autoland, low visibility approach and landing, precision approach, tactical decision tools.
8. Enhanced vision systems, pattern recognition and data fusion.
9. Synthetic 3D vision with terrain and obstacle information and visualisation, automatic warnings to crew if flight path intersects with terrain.


Warning System

To reduce the risk of aircraft colliding with each other, or by undertaking Controlled Flight Into Terrain (CFIT), aircraft are fitted with an array of collision warning systems. Note that human aspects of responses to warning system alerts are dealt with in the "Human Factors" research and technology area, and fire protection warning systems are dealt with later in this Area.

1. Sensors. ground collision avoidance (GPWS).
2. Sensors. airborne collision avoidance systems (ACAS).
3. Alerting systems (audio, warning lights, displays. map view, profile view, 3D perspective view).
4. Integrated terrain awareness and warning systems.
5. Turbulence warning. windshear, wake vortex, clear air turbulence.
6. Ground and airborne detection of meteorological icing conditions.
7. Integration of airborne detection with atmospheric data received from outside the aircraft for real-time crew information and for transmission to other users.
8. False alarm reduction.


Electronics & Microelectronics for on-board systems

Research and technology addressing the development, integration, validation and use of new electronic and micro-electronic systems on aircraft, including the facilitation of the More Electric Aircraft concept.

1. New materials.
2. Power, weight and cooling requirement reductions.
3. Reliability increase.
4. Component and system interfaces and architectures.
5. MEMS.


Sensors integration

Fusing of data from sensors to present a single, unambiguous picture to the system users.

1. Integrated modular avionics.
2. System interfaces and architectures.
3. Algorithm development, testing and validation.
4. Application to navigation, aircraft status and flight data systems.


Flight Data/Flight Recording

Commercial aircraft are required to be fitted with devices that record flight information that can be used to help reconstruct the events leading up to an aircraft incident or accident.

1. Cockpit voice recorder (CVR). recording technology.
2. CVR sensors (microphones).
3. CVR. reconstruction tools and algorithms.
4. Flight data recorder (FDR). recording technology.
5. FDR. sensors.
6. FDR. reconstruction tools and algorithms.
7. Passenger cabin recording equipment.


Communications Systems

Covers communications between aircraft and the ground, as well as communications on-board the aircraft. Links with 'Communication Technology'.

1. Radio communication systems (HF, VHF, UHF, AM/FM), analogue and digital.
2. Integration of communications systems.
3. Communications systems architecture (including routers, WANs and gateways).
4. Reductions in power requirements, weight reduction.
5. Communication systems components. waveguides, antennas.
6. Data transmission. datalinks (VHF datalink, air-air datalink, broadcast datalink), telemetry, ACARS.
7. On-board intercom systems.
8. Satellite communications. voice, datalinks, communications integration.



ATM systems require accurate and timely knowledge of the location and identification off all aircraft within their airspace. Close links to ATM area.

1. IFF transponders (selective integration, Mode S, Mode S subnetwork, Mode S SARPS, Mode 5).
2. Non-co-operative identification (JEM etc).


Avionics Integration

With the increasing complexity of aircraft avionics, their integration into an effective system is required. Evaluation of the interactions between each sub-system is required. This include electronic flight instrument systems, flight management, air data, attitude reference and power distribution systems.

1. Functional verification.
2. Integration testing.
3. Maintenance of integrated avionics system.
4. Operational characteristics of integrated avionics systems.


Optics - Optronics - Lasers - Image processing and data fusion

Research and technology associated with the use of optical, electro-optical and optronics systems; and the collection and fusing of data from such systems.

1. System interfaces and architectures.
2. Reductions in power, weight and cooling requirements.
3. Integration with avionics.
4. Radar data processing (RDP).
5. Sources of surveillance data.
6. Optics sensors. enhanced vision sensors, light intensifiers, solid state lasers, MOEMS (Micro electro-optical mechanical systems).
7. Nano technologies.
8. Signal processing. 9. High bandwidth data transmission. 10. Data fusion. architectures, algorithms, validation.


Electronic Library System

Research and technology associated with the collection and presentation of technical and operational material relating to aircraft, in a digital form which can be accessed by flight crews and maintenance staff through computers, either networked or stand-alone.

1. Collection and digitisation of data.
2. Data management.
3. Data display (laptops, PDAs, tablet/slate PCs).
4. System characteristics (e.g. physical robustness to harsh operating environment).
5. Connectivity and ground infrastructure issues.
6. IT associated tools (e.g. virtual reality) for enhanced maintenance support.


Aircraft health and usage monitoring system

Research and technology associated with a network of sensors tasked with monitoring the health, usage, fatigue and performance of various aircraft systems and sub-systems.

1. Application of prognostic health management to improve condition-based maintenance.
2. HUMS sensors. characteristics, interfaces, management, scheduling and self-monitoring.
3. Data management. storage, archiving, retrieval, analysis.
4. Integration of diagnostic and prognostic systems.


Smart maintenance systems

Complex systems comprising electronic, electro-mechanical and hydraulic sub-systems must be engineered with ease of maintenance as a design goal. In a fielded system, effective preventive maintenance achieved through online system health monitoring, damage detection and smart diagnostics and repair strategies will yield significant saving in the total life cycle costs, by improving the systems' reliability, maintainability and availability.

1. Autonomous logistics. anticipatory maintenance and repair.
2. Provisions of information to maintenance staff.
3. Reductions in logistics and maintenance support requirements.
4. Automated logging of system and sub-system performance.
5. System interfaces and architectures.
6. Self-healing and self-repairing systems and materials.
7. Maintenance monitoring systems.
8. Failure tolerant systems.
9. Computer-based maintenance support and training, methods and materials.


Lighting systems

Research and technology into internal and external aircraft lighting systems.

1. Lighting technologies. LED, incandescent, fluorescent, high-density discharge, electro-luminescent.
2. Operational considerations. power requirements, reliability, flexibility in installation and operation, reduction in maintenance requirements.
3. Safety considerations. robustness, redundancy.
4. Lighting types. ambient cabin, task cabin (reading etc), information and guidance, safety, flight-deck, external anti-collision.


Aircraft Security

Aircraft security measures are the physical protection measures required in order to protect the aircraft and the passengers and crew when they are on-board.

1. Systems and procedures for identification and access of personnel to the flight deck.
2. On-board explosives detection systems.
3. Alarm systems (e.g. panic alarms for cabin staff, seatback phones for passengers).
4. Cockpit security monitoring systems (voice recorders, video surveillance etc).
5. Passenger cabin security monitoring systems (voice recorders, video surveillance etc).
6. Security systems deployed by armed sky marshals.
7. Tamper-proof and multiply-redundant transponder systems.
8. Modified collision and terrain-avoidance systems (to prevent aircraft from being crashed deliberately).
9. Modified automatic landing systems (to enable forced landing of aircraft by ground authorities after it has been hijacked). Comment: see also Area 'Structures, Materials & Processes'.


Electrical Power Generation & Distribution

Research and technology associated with the generation, distribution, integration and control of electrical power on board the aircraft, both AC and DC. The development of aircraft power technologies that are simple in design and have a wider range of application will result in lower acquisition and maintenance costs, and will facilitate the development of the More Electric Aircraft.

1. System components. generators, alternators, converters, inverters, batteries, circuit protection (circuit breakers, current limiters, automatic bus transfer), wiring, connectors, control systems, measuring instruments, warning indicators.
2. System characteristics. power quality, isolation, reliability, interface standardisation.
3. Issues. electrical load analysis, power quality testing, installation assessment, distribution and load management.
4. Integration and validation of technologies.


Pneumatic systems

Pneumatic systems provide compressed air to pressurise the aircraft water supply system, for wing ice protection, and as emergency back-up for hydraulic sub-systems.

1. Components. LP air cylinders, pressure gauges and warning lights, pipework, valves and fittings, filters, seals.
2. Wing ice protection. Ice sensor integration for Protection on Demand, hybrid wing heating.
3. Provision of emergency oxygen systems for passengers and crew4. Emergency inflation systems (rafts, escape slides etc).


Hydraulic power generation & distribution

Research and technology associated with the use of hydraulic systems (power generation, control and distribution).

1. Components. reservoirs, pumps, valves (pressure regulators and directional control), accumulators, filters, supply and return lines, seals, actuators, fittings and control systems.
2. Design. tools to support modelling for dynamic performance analysis.
3. Interfaces with other aircraft systems.


Passenger and freight systems

Research and technology associated with the development of improvements to aircraft seating, safety restraints and interior systems, including the integration of on-board passenger services.

1. Passenger seats - configurations (side-facing, rear-facing, bed-seats), comfort (suppression of vibration etc), ergonomic design, safety crash worthiness, integration of value-added services.
2. In-flight cabin systems - electronic business/office systems, airline information, flight information/interactive maps, internet access, telephone access, audio/video and other multimedia services on demand, video surveillance monitoring and recording.
3. Restraints - airbags, seat belts, child restraints, analysis of operational effectiveness.
4. Safety systems - lightweight breathing systems, smoke hoods, evacuation systems (slides etc).
5. Cargo systems - loading, handling, restraining, monitoring, integration.


Environmental control System

Aircraft environmental control systems (ECS) provide the means to ensure a controlled environment within the aircraft interior, in terms of air supply, air flow, temperature, pressure and humidity. In addition to normal cabin-air requirements, certain areas of aircraft have special ECS-related operational and safety requirements, such as adequate cooling of equipment or removal of smoke or odours.

1. Provision of fresh air - bleed air, ozone converter, air conditioning/cooling packs (heat exchangers, turbines, compressors, air mix chambers).
2. Air filters - activated charcoal, HEPA, filter status monitoring.
3. Exhaust of cabin air - pressure control, outflow valves.
4. Recirculation system - CO, CO2 monitoring and removal.
5. Temperature, humidity control.
6. Cabin ventilation and ducting system - flow patterns analysis, tools and modelling, zonal distribution, avoidance of draughts and stagnant areas.
7. Control systems - status indicators, parameter level and system warning indicators, manual regulators for emergency use.
8. Air quality monitoring and analysis - development of comfort index.
9. Ground operations of ECS - APU, external air conditioning units.
10. Personal climate control facilitation (temperature, airflow, humidity).


Water and waste systems

Water is required for crew and passengers, for both drinking and cleaning purposes. Waster from passengers and crew needs to be stored and disposed of in an environmentally responsible manner

1. Fresh water systems - storage, tank capacity, distribution system and flow rate, pressure system, disinfection (chlorine, anodic oxidation), ground handling interface - filling and emptying.
2. Grey water - disposal system (heating, in-flight spraying).
3. Toilets - reliability, maintainability, technologies (recirculation, vacuum), storage and disposal of waste.
4. Plumbing - pipework, valves, fittings, filters.
5. Cabin waste - solid/semi-solid/liquid, storage, compaction, avoidance of smells.
6. Ground handling interface.


Fuel systems

Research and technology associated with the aircraft fuel storage and distribution systems.

1. Storage - tank location, design, construction.
2. Distribution systems - pipes, valves, isolation systems, pumps.
3. Management system - level indicators, actuators, control system.
4. Refuelling and defuelling systems.
5. Safety issues - fire protection measures, electrical bonding straps and jumpers.


Landing gear and braking systems

Research and technology associated with the landing gear, wheels, tyres, braking and steering systems.

1. Landing gear - configuration and design, shock absorption (active and passive damping), load control systems, control theory aspects, power demand, corrosion protection.
2. Wheels - construction, design (main and nose wheels).
3. Tyres - construction, design, temperature and pressure sensors and monitoring, operation under loads, wear prediction.
4. Braking system - materials (carbon, steel), anti-skid systems (integrated brake monitoring, anti-skid valves, brake management systems), automatic braking systems, temperature sensors and monitoring systems, accumulators, pressure transducers.
5. Steering system - nosewheel steering.


Fire protection systems

A fire protection (FP) system in an aircraft includes passive and active FP means. Passive FP is achieved by using fireproof, or fire-resistant, materials. Active FP systems comprise smoke, fire and overheat detectors with indicators, fire suppression devices and a management control sub-system.

1. Passive protection - fireblocking layer on materials (e.g. cabin seats), fire-resistant fittings, floor coverings and non-structural applications.
2. Detection systems - smoke (back-scattering, optical attenuation), fire (gas sensing, near IR, IR), overheat, hot air leakage.
3. Fire suppression - halon, watermist/nitrogen flooding, environmental impact, piping, valves, on-board inert gas generation systems, hand-held extinguishing systems.
4. Control systems - maintenance panels, cockpit display panels, visualisation of system status, audible alerts, design (zonal configuration, redundancy, reliability, systems research, analysis of operational incidents), BITE.