Avionics equipment is an integral part of the air navigation system. Areas of on-board equipment development are closely integrated with the perspective concepts of development of CNS / ATM concept based on development trends of modern digital, computer, microelectronic, micromechanical techniques and fans.
International Organization EUROCONTROL has a vision of CNS / ATM concept as a single operationional envoronment, all the components of which are inextricably linked . The general structure of CNS / ATM (Overall ATM / CNS Target Architecture - OATA) is shown in Fig. 207. Equipment of digital data exchange creates an information gap between different structural elements, combining airborne and ground-based equipment.
Fig.207.The overall structure of CNS / ATM
According to the development of the concept of CNS / ATM program OATA (EUROCONTROL) provided basic perspective directions of avionics equipment development. Within the program OATA the representatives of the research department of Boeing Research and Technology Europe (BR & TE) and Airbus were involved in the problems of the development of the equipment. According to the study there were separated three stages of avionics equipment : 2007, 2011 and 2020 years.
2007 – a short term, based on the existing paradigm of operation of air navigation system using existing avionics equipment with a gradual increasing of the role of digital data network and development of the concept of ADS-B.
2011 - the medium term, which includes more advanced flight planning methods through the gradual integration of airborne and ground equipment, the result of which will create a single information environment between "Onboard" and "ground". In addition, it is planned to use more complex RNP-RNAV navigation systems that will improve the accuracy of navigation tasks and facilitate more flexible use of airspace.
2020 - a long-term perspective, which involves complex forms of flight, based on close cooperation between avionics equipment and ground infrastructure for all phases of flight. Much attention is paid to planning operations to minimize conflicts and providing optimal choices for manual flight trajectories.
Avionics equipment must support laid in three stages purposes of considering the gradual evolution of electronic technology.
Overall, according to OATA there is a general model of the optimal composition of avionics equipment that meets the current pace of equipment (Fig. 208).
The module of flight control provides the determination of the appropriate trajectory, based on close cooperation of ATS, airline and pilots of ACFT.
The control module provides flight control for:
- RNAV - flight control is reduced to determining the location of the ACFT and its relation to the planned trajectory.
- Flight from point to point by means of navigation through beacons. This mode is used in the airspace in which RNAV is available.
The landing module provides control of the ACFT while landing. Systems that provide location information while landing - ILS, MLS and GLS.
The control module includes means of controlling the ACFT in the air, including the engine.
Fig. 208. The structure of avionics (OATA)
The module of terrain warning performs detection of potential dangerous convergence of the ACFT with the earth's surface or with artificial obstacles and issues appropriate recommendations to avoid a possible collision.
The module of warning about dangerous convergence between ACFT detects hypothetically possible conflicts between different ACFT and provides guidance to pilots for their timely resolution.
The observation module is based on the receiving of ADS-B signals from neighboring ACFT for tracking air traffic.
This module displays information about:
- Location (actual location in space compared to the target);
- Objects that can be dangerous (relief underlying surface and air traffic);
- Airport (map, taxiing routes);
- Warning of dangerous air traffic and relief;
- Meteorological data and aeronautical information databases.
The module of aeronautical database contains static information necessary for the operation of all avionics modules, including information about the routes of flight, navigation data, meteorological data, information about airports and the underlying surface topography.
The module of ACFT location determination combines data from different navigation systems such as GNSS, DME and IRU to determine accurate and actual coordinates.
The module of sensory equipment provides the avionics data from various onboard sensors that measure various physical quantities.
The module of equipment interactions management generates digital data messages that are emitted by channels: ADS-B, ADS-C, Mode S, Mode AC.
Generalized scheme of interaction between airborne avionics equipment is shown in Fig.209.
Fig.209. The generalized scheme of interaction between avionics equipment (OATA)