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Inconsistent Aeronautical Information (Hz16)

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Article Information
Category: Hazards Hazards
Content source: SKYbrary About_SKYbrary
Associated ATM Functions
  • Information management-Aeronautical Information Service

Hazard Description

HAZ004 - Inconsistent Aeronautical Information between Actors of Downstream Data Chain

The lack of defined roles and responsibilities for Data Chain actors, the lack of standard data quality control procedures and the differences registered with International Civil Aviation Organisation (ICAO) Annex 15 requirements all lead to inconsistent Aeronautical Information (AI) between the actors of the Downstream Data Chain. Some of the required actions are actually dependent on how a State manages its Aeronautical Information Service processes and procedures.

Hazard Identification Document

CHAIN Preliminary Safety Case


  • Determination of who the recipients of a change are depends on how the country manages its information distribution service. The distribution list can be corrupted in the same was as any other data but recipients will know if they do not get the data because distribution is on a monthly basis.
  • When there are no changes, a Notice To Airmen is usually published to say that nothing has changed. However this does not happen for everything, for example AIP supplements.
  • Inconsistency between publications can be detected if using European AIS Database (EAD) because everyone is using the same source of information.


  • No mechanism exists to minimise inconsistencies between States Integrated Aeronautical Information Packages (IAIPs)
  • Diverse interpretation of Notice To Airmen - due to the current nature of Notice To Airmen some distributors add or alter Notice To Airmen data to “clarify” the meaning. This can introduce different interpretations by downstream actors
  • Inconsistent resolution of resource loading issues
  • Data Distribution does not distribute regulated IAIP to subscribed Data Users in accordance with the AIRAC cycle
The timely delivery of data for preparation and publication is an issue. There are contingency procedures to deal with late publications, however the process is costly and errors can be introduced due to people working under pressure, increased workload, insufficient resources and information provided by originators too late.
  • Ineffective co-operation or co-ordination between different departments in Data Publication and Data Preparation within a State or across States
  • Lack of awareness among Data Originators of the importance of adhering to AIRAC rules
  • Error feedback inconsistencies in the AIS co-ordination with Data Origination
  • Inconsistencies between issued AI and electronically published AI in Data Distribution due to the use of different representations for data between paper and electronic system
  • Inconsistencies by differences between paper and electronic versions of the same AI
  • Inefficient co-operation/co-ordination between departments in communicating any last minute changes in electronically published AI which need to be reflected in the paper version of AI at issuing
  • Inconsistent representation of AI between States and Data Application/Integration and Data End Use
State distributed IAIPs having a different representation to the representation of data used by Data Application/Integration and Data Use is currently an issue, especially where the representation is paper-based. The issue is that downstream actors need to extract the data from the paper-based product and convert it to digital form in order to be able to use it; this is a process which results in data synchronisation problems and it is a source of errors as it is a process involving manual manipulation of data.
  • Inconsistent electronic IAIPs distributed from different AIS
Standardised format of electronic representations of IAIPs across States or the management of different representations across States has been identified as an issue. Electronic representations of IAIPs across States are not standardised yet. The lack of a standard has led to divergent implementations, manifested through heterogeneous technical solutions, navigation structures and presentation formats.
  • Inconsistent paper IAIPs distributed from different AIS
Standardised format of paper representations of IAIPs across States or the management of different representations across States has been identified as an issue.
  • No check to ensure that all subscribed recipients receive the same paper copy of IAIP
There is a general lack or inconsistency of feedback from Data Users (currently not mandated). This means that errors can go unreported.

Causal Prevention and Mitigation(s)

  • Include in International Civil Aviation Organisation (ICAO) Annex 15 measures to be implemented to minimise the mechanisms through which inconsistency between States IAIPs can arise
  • Mandate that where Notice To Airmen are amended the original Notice To Airmen must also be included
  • Define and implement contingency management and coordination procedures in the event of resource overload
  • Produce specification for automated transfer of AI between actors
  • Define Service Level Agreements between actors
  • Mandate Service Level Agreements
  • Develop AIS procedures that are more efficient
  • Define and implement contingency management and coordination procedures in the event of resource overload
  • Improve awareness of Data Originators to AIRAC Cycle
  • Develop processes that minimise inconsistencies between IAIP
  • Develop procedures for consistency checking of all paper and electronic IAIP
Where a State issues both electronic and paper versions of the same AI, reviewing the paper version against the electronic version of the published AI can reduce the frequency of inconsistencies between the two. It was not clear at present whether the final quality check of the issued AI for distribution would carry out this type of review.
  • Develop specifications for automated transfer of IAIP to Data Application/Integration (e.g. automatic translation of Aeronautical Information Exchange Model (AIXM) to ARINC)
  • Mandate a standard digital format for AI interchange for AIS e.g. AIXM, Electronic AIPs (eAIP)
This issue could be addressed if AIS migrate to EAD as inconsistencies between digital State AIS data are checked for as part of the level C Static Data Checks in EAD.
  • Mandate a standard format for paper AI interchange for AIS
  • Provide mechanism to facilitate and encourage error feedback from data users


No effects were identified with respect to provision of ATM services. However the lack of inconsistent AI could lead to increased ATC workload.

The identified consequences were all in relation to actors involved in the current Data Chain.

Source Document

Further Reading

Commission Regulation (EU) No 73/2010 of 26 January 2010 laying down requirements on the quality of aeronautical data and aeronautical information for the Single European Sky</protect>