Data integrity monitoring (Phase 2 P-02)


The objective of Controlled and Harmonised Aeronautical Information Network (CHAIN) is  to improve the accuracy and quality of the originated aeronautical data and its management from the point of origination to the point of publication and to subsequently enable enhanced processing throughout the entire aeronautical data chain.

The purpose is to support aeronautical information regulators and service providers in implementing and maintaining traceable, controlled and auditable processes in compliance with ICAO Annex 15 requirements for data quality with a focus on data integrity.

The scope of CHAIN covers flight critical and essential navigational aeronautical data (e.g. a runway threshold coordinates and heights) as established in ICAO Annex 15, supplemented by the industry standards EUROCAE ED-76 and ED-77.

The vision is to assist in the establishment of an automated aeronautical data supply chain to support AIS regulators, AIS providers and aeronautical data originators to enable system-wide interoperability.

  • Note: The time of operation for CHAIN was set from March 2005 to October 2007


Present and future navigation and the air traffic management systems are dependent on aeronautical data and many of them require significantly higher aeronautical data quality than is currently available. The high-quality data means a data product with a minimum of one error in 100.000.000 units.

The improvement of aeronautical data quality to meet the levels required by ICAO is a long standing issue which, due to complexity of the data processes, reliance on paper based systems and human input has not been solved yet.

In consequence, there is a low compliance rate amongst States in achieving the specific aeronautical data quality requirements established by ICAO Annex 15 such as: accuracy, resolution, protection, traceability and timeliness, but in particular integrity.


Aeronautical Data Supply Chain

How does the aeronautical data get into the cockpit? It is a long supply chain which involves a multitude of actors. The data originated at an aerodrome has to go through at least 5 individual units to get to the end-product in an aircraft. The Data Originators (e.g. aerodrome, navaid owner, airspace designers etc.) supply their information into the AIS. The AIS produces the AIP which may be a paper or an electronic copy. The AIP produced by the AIS is then processed by the Data Houses (e.g. Jeppesen, EAG, Lufthansa Systems etc.). They take the data which is required from the AIPs, to then format it, ready for packing. Once the information is there, it is passed to the Data Packers (e.g. Honeywell, Garmin, Rockwell Collins, Smiths etc.). The Data Packers pack the data for the specific FMSes of the different aircraft.


The core problem appears when tasks are performed by multiple actors based on manual processes with the existence of numerous transaction points. At each of these points data may leave a (semi) electronic (or even a fully manual) environment and are transferred in paper form (=media break) rather than in electronic form. A survey for European States showed that in average 11 different Data Originator categories provide aeronautical information directly to AIS. Each Data Originator works to individual standards, processes and procedures and submits reports in paper form sometimes supplemented by email.

The subsequent process functions re-type the aeronautical data before processing it further. Aeronautical data are repeatedly re-entered and re-checked whilst each time integrity maybe degraded or lost, audit trails broken, traceability disabled and the flexibility in processing constrained. This problem is intensified by the fact that aeronautical data changes may occur at AIRAC cycle (28 days).
In effect, applied processes are highly inefficient, error rich with a likely potential of safety impact. If at any point in the aeronautical data chain, in the transformation of the formats of the information things go wrong, then there is a lack of integrity. If the Data Originator and AIS do not provide a very clear, very understandable set of information, it can lead to ambiguity. An ambiguity leads to that Data Packers packing the data for the aircraft in a different format or with different instructions so that the aircraft can not fly the route that is planned by the Data Originator.

The aeronautical information is required to be very clear, totally unambiguous so that the required integrity is not lost. Because any change or loss of integrity means that the aircraft will fly different tracks and even worse it could fly into the ground.

The CHAIN Overview leaflet (pdf) provides a detailed overview of the various CHAIN deliverables.


Objective and deliverables

To respond to the identified problems in aeronautical data chain the following objectives were established for CHAIN:

  • Improve accuracy and quality of aeronautical navigational data with focus on data integrity;
  • Enhance data management by establishing common procedures/processes to enable interoperability;
  • Enhance the transfer of aeronautical information between origination & publication; and
  • Support States to establish system-wide traceable, auditable processes.

In order to achieve the established objectives CHAIN provided the following deliverables:

  • Harmonised Specifications in support of automated processes
  • Training

Harmonised Specifications in support of automated processes

The objective of this CHAIN deliverable is to provide a common operational specification for an automated data quality process supporting States in developing specific, national solutions through a harmonised approach. It also assists in choosing from the existing work flow management solutions available on the market the most suitable and customisable one for the AIM domain. Note: there is no such solution suitable in its current form to the aeronautical data chain. The deliverables consist of a study on existing commercial of the shelf (COTS) work flow management solution -and- a common specification in support of an automated data integrity process. The concept of Automation addresses the transfer process in the data chain. At each step in the process an identical set of embedded functions must be performed by all actors in order to lead to a situation of guaranteed hand-over of data being interoperable, traceable and quality assured.The automated process must be designed to act as an interface between two adjacent actors in the data chain. It starts with the operations that occur immediately after the last process of data transformation (i.e. verifications, validations, approval, etc.) and it ends immediately before the next data processing in the data chain (i.e. authentication, verification, validation, etc.)


Six CBT modules explain the issues related to the aeronautical data supply chain, demonstrate how quality can be enhanced and how integrity can be preserved by applying the individual CHAIN solutions to the data supply processes within States and Organisations. Target Audience are: Civil & Military actors (technical, operational and managerial) having vested interest in Aeronautical Information (AI) and/or responsibility for the provision of AI for or on behalf of a State. In particular those are: AIS/AIM Providers, AIS/AIM Regulators, Data Originators/Providers and related Training units. The estimated duration of the training is 10 hours (net time average rate in case of good level of English and sound domain knowledge).
The course is accessible via the EUROCONTROL Training Zone, available to the global learner community and is free of charge. However, learners need to formally register to enable the enrolment to the course.

  • Assessments have been built-in at every lesson/topic so that application can take place quickly once the required knowledge is acquired. And finally at the end of each module you may obtain an Attendance certificate that will pop-up for print automatically.

Guidance material

The objectives of CHAIN guidance material were to provide and implement standardised procedures and processes in the aeronautical data chain and achieve quality requirements set up by ICAO standards.

The CHAIN guidance material consist of a series of distinct and independent elements providing a ‘suite’ for different types of actors serving the challenging institutional environment in the aeronautical data supply chain:

  • Data integrity family of documents; comprises 5 documents and determines the principles for management of the overall process applicable to all steps.
  • Compendium of standards; presents a consolidated view of quality related requirements, with an emphasis on data integrity, from a variety of sources (i.e. ICAO, ISO, European Commission, EUROCAE and JAA).
  • Data Process Mapping; models the supply chain to map individual critical and essential data elements (as defined by ICAO Annex 15) to processes, key steps and functions including transaction processes.
  • Standard Input Forms (SIFs); increases the integrity of aeronautical data by providing a single input, multiple use and security, to provide a common method throughout AIS data flow and to use AIXM for interoperability.
  • Service Level Agreements (SLAs); series of interrelated elements in form a comprehensive package to facilitate the establishment of agreements between data providers and Aeronautical Information Services under the umbrella of a regulator.
  • Validation and Assessment criteria; a guide and tool for stakeholders performing a Data Integrity self audits and for regulators preparing formal Data Integrity audits. Together with the AIP Audit Assistant (AAA), the Validation and Assessment Criteria is provided as part of the Audit Tool application

All related documentation can be downloaded from the AIM/SWIM OneSky Teams library.