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The revised ICAO Annex 15 (draft) recommends that “Global communication networks and Web services should, whenever practicable, be employed for the provision of Aeronautical Information Products.” The PANS-AIM document does not provide any further details on this topic.The ” The ultimate goal is to provide aeronautical data through Web services. The provision of the data sets (as files) is considered as an intermediate step in that direction.The  The rules provided in this section ensure a minimal harmonisation of the provision of data AIP Data sets as files.

One or more files

Info
titleRecommendation

When not practical to provide the AIP Data Set as a single consolidated file for each State or Territory (for example, because of an excessive size), separate files shall be provided for each feature or group of closely related features, such as:

  • Routes, points and navaids
  • Airports, runway, TLOF
  • Aeronautical ground lights
  • Airspace
  • En-route holdings

Use of compression

The size of an AIP Data Sets in AIXM format is likely to be in the range between 100 MB and up to 1-2 GB (if provided for an entire region). Such files have very good compression rates (up to 10 times) with widely used standards, such as ZIP. In order to reduce the transmission times and the archiving size on the client side, the AIP Data Sets should be exchanged in compressed formats. The use of compression algorithms provide a side benefit, as they guarantee the integrity of the files, through the use of CRC or similar mechanisms.

Info
titleRecommendation
When made available as a single XML file, the AIP data set should be compressed using a widely used compression algorithm, such as ZIP.

File name

The ICAO PANS-AIM, item 5.4.1.4 requires a “checklist of data sets shall be made available through the same distribution mechanism as used for the data sets”. This implies requires that each data set may be uniquely identified in some wayby its name, so that it can be listed. Therefore, a naming convention for the AIP Data Set files is proposed in this section.

Info
titleRecommendation

An AIP Data Set file should have the following name structure “CC“CC_CC_CC…[Territory]_AIP_DS_TypeVariant[_Part]_YYYYMMDD[_AIRAC].xml", where:

  • CC represents the 1-letter or 2-letters ICAO Country code(s) of the State(s) under which authority the data set is published, according to the ICAO DOC 7910 - Location Indicator;
    Note: When a Data Set is published for an entire region, as result of a regional database agreement, CC may be replaced by a code representing that region, such as “EU” in the case of the European AIS Database.

  • [_Territory] is optional and is the official name of the Territory covered by the data set, if applicable;

  • AIP_DS is a fixed text (meaning “AIP Data Set”);

  • Type Variant is a mandatory element and it can take one of the following values (based on the Data set variants guidelines):

    1. FULL - when the file contains a complete AIP data set or a subset thereof;UP

    2. DIFF_DBL BL - when the the file contains an AIP Data Set - Baseline Update or a subset thereofDifferences variant coded with BASELINE TimeSlices;UPD

    3. DIFF_DELTA - when the file contains an AIP Data Set - Delta Update or a subset thereofDifferences variant coded with PERMDELTA TimeSlices.

    4. SUP - when the file contains a Supplementary AIP Data set.

  • [_Part] is optional and indicates that the file constitutes a subset of the complete AIP data set provided by the State. Note: the exact split in parts and their names is left at the discretion of each State;, if applicable. For example, values such as "_Civil", "_Military", "_Navaid", etc. could be used. 

  • YYYYMMDD is the start of effective date in the format year, month, date;

  • “_AIRAC” AIRAC” is optional and it shall be appended for Data Sets that contain changes complying with the AIRAC cycle rules.

...

“EB_EL_AIP_DS_FULL_20181123_AIRAC.xml” - for the AIP Data Set of Belgium and Luxembourg

Relation with metadata

It may be observed that most of the elements that enter in the composition of the file name are also provided as metadata. The purpose of the file name is to enable a quick identification of the data sets of interest. However, the data users should not rely only on the file name in order to decide on the suitability of processing/using a data set instance. The complete metadata should be used for this purpose.