AIRAC adherence monitoring (Phase 1 P-03)

Aviation "environment" data is constantly changing:airspace structures and routes are revised, navigation aids change, SIDs and STARs are amended, runway and taxiway information changes.

It is essential, for both efficiency and safety, that Pilots, Air Traffic Controllers, Air Traffic Flow Managers, Flight Management Systems and Aviation Charts all have the same data set. But how can this be achieved? The answer is AIRAC.

What is AIRAC?

AIRAC stands for Aeronautical Information Regulation And Control and stems from the ICAO Annex 15 - Aeronautical Information Services (AIS) document and defines a series of common dates and an associated standard aeronautical information publication procedure for States.

In short it defines that in all instances, information provided under the AIRAC system shall be published in paper copy form and shall be distributed by the AIS unit at least 42 days in advance of the effective date with the objective of reaching recipients at least 28 days in advance of the effective date. Whenever major changes are planned and where additional notice is desirable and practicable, a publication date of at least 56 days in advance of the effective date should be used.

Three dates are to be remembered from this:

  • Effective date: date at which changes take effect.
  • Publication date: date at which the AIS organisation sends out the information (should be at least 42 days -56 for major changes- before effective date).
  • Reception date: date at which the user should receive the publications (should be at least 28 days before the effective date).

The two weeks between publication date and reception date is basically to allow for postal distribution of the (mostly) paper publications.

Cycle

 

The AIRAC cycle was adopted by ICAO in 1964 and further improved over the years. Key are the worldwide effective dates with 28 days intervals (e.g. 4 August 2005, 1 September 2005, 29 September 2005, ...). Effective days are always on a Thursday.

It may look indeed like a long period, 28 days, or even 56, but it should be understood that aeronautical information changes (mostly published through so called AIRAC Amendments) require:

  1. Changes to local systems which includes interpreting, re-typing and re-coding the information.
  2. Verification and Correction as publications are unfortunately seldom perfect. 
  3. Validation against other data; Flight Plans are just one example. 
  4. Re-distribution, hereby think of Charts and Flight Management Systems to a fleet which can be anywhere in the world.

Dates

The AIRAC effective dates

The AIRAC effective dates are published in ICAO Doc 8126, the Aeronautical Information Services Manual. They are also referred to in most national AIPs when providing the data delivery dates for data originators.

 

# 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020*
1 14 Jan 13 Jan 12 Jan 10 Jan 9 Jan 8 Jan 7 Jan 5 Jan 4 Jan 3 Jan 2 Jan
2 11 Feb 10 Feb 9 Feb 7 Feb 6 Feb 5 Feb 4 Feb 2 Feb 1 Feb 31 Jan 30 Jan
3 11 Mar 10 Mar 8 Mar 7 Mar 6 Mar 5 Mar 3 Mar 2 Mar 1 Mar 28 Feb 27 Feb
4 8 Apr 7 Apr 5 Apr 4 Apr 3 Apr 2 Apr 31 Mar 30 Mar 29 Mar 28 Mar 26 Mar
5 6 May 5 May 3 May 2 May 1 May 30 Apr 28 Apr 27 Apr 26 Apr 25 Apr 23 Apr
6 3 Jun 2 Jun 31 May 30 May 20 May 28 May 26 May 25 May 24 May 23 May 21 May
7 1 Jul 30 Jun 28 Jun 27 Jun 26 Jun 25 Jun 23 Jun 22 Jun 21 Jun 20 Jun 18 Jun
8 29 Jul 28 Jul 26 Jul 25 Jul 24 Jun 23 Jul 21 Jul 20 Jul 19 Jul 18 Jul 16 Jul
9 26 Aug 25 Aug 23 Aug 22 Aug 21 Aug 20 Aug 18 Aug 17 Aug 16 Aug 15 Aug 13 Aug
10 23 Sep 22 Sep 20 Sep 19 Sep 18 Sep 17 Sep 15 Sep 14 Sep 13 Sep 12 Sep 10 Sep
11 21 Oct 20 Oct 18 Oct 17 Oct 16 Oct 15 Oct 13 Oct 12 Oct 11 Oct 10 Oct 8 Oct
12 18 Nov 17 Nov 15 Nov 14 Nov 13 Nov 12 Nov 10 Nov 9 Nov 8 Nov 7 Nov 5 Nov
13 16 Dec 15 Dec 13 Dec 12 Dec 11 Dec 10 Dec 8 Dec 7 Dec 6 Dec 5 Dec 3 Dec
14                     31 Dec

 

'Freeze' dates

Each recipient has an internal date, called 'freeze' date, before the effective date after which he can not accept changes anymore.
E.g. Aircraft Flight Management Systems need the data often 17 days before the effective date to allow for the information re-coding (into ARINC424 format), information uploading and distribution.

Note that these freeze dates are strictly speaking the recipients own business, however they become important in the context of AIRAC Non-adherence.

Christmas and New Year

ICAO Annex 15 - Chapter 6 is clear: "The use of the date in the AIRAC cycle which occurs between 21 December and 17 January inclusive should be avoided as an effective date for the introduction of significant changes under the AIRAC system".

And in ICAO Doc8126 - Chapter 4, because of reduced staffing and increased postal delays, "it is recommended that the AIRAC cycle date occurring in the 28-day period from 21 December to 17 January (both dates included) no longer be used as an AIRAC effective date for the introduction of significant operational changes. States experiencing similar problems during other holiday periods may wish to adopt a comparable system

Non-adherence

The Issue

The issue is that unfortunately sometimes 'AIRAC-type' aeronautical information publications do not follow the AIRAC cycle. This is generally referred to as AIRAC Non-adherence. Publications are published/received too late, cancelled/postponed at the last minute or published incorrectly as non-AIRAC. And then, the troubles start. Users are unaware of latest changes. Different users are using different versions of the aeronautical information. Charts are inconsistent with Flight Management Systems. Pilots fly around with outdated information ... In short, users are not sure of anything anymore.

Safety

Investigations in Europe have shown that as reported by three (well-known) European States, in 1999, there were at least twenty safety incidents stemming from AIRAC Non-adherence. Whether this was all or just the tip of the iceberg is impossible to say. European wide, systematic, standardised safety reporting would be required to answer this question satisfactory.

Other consequences have been shown during an AIRAC Adherence Stakeholder Meeting (April 2000). An analysis session conservatively estimated that, overall in Europe, pre-flight consequent to European non-adherence to AIRAC costs are 11 Million Euro. These costs are mainly Staff (having to continuously check for latest information and acting upon it) and Reproduction (reprinted charts etc) costs.

This happens every AIRAC cycle. (European) monitoring results over the last three years have shown that, on average, three significant AIRAC Non-adherence events occur per cycle.

Data providers

All users, including commercial data providers like Jeppesen, Lufthansa Systems Aeronautics, Navtech (to name a very few) depend on aeronautical information publications as published by a national AIS. They are affected as much as any aircraft operator. So as any Briefing Office will tell you; Always check for the latest information before taking off!

The freeze dates

Because of the different freeze dates (and it is re-iterated that it is the recipients 'right' to act so) there is, in the case of a late publication, an increased chance that different end-users find themselves with different versions of the aeronautical information (Just think of an Amendment that arrives after the freeze date of one user but before the freeze date of another).

The causes

At a first sight, it seems to be all the fault of the national AIS whose prime responsibility it is to publish on time. However, things aren't that simple. An AIS is not the 'creator' of any aeronautical information and depends fully on many different data originators (route & airspace planners, procedure designers, navaid maintainers, airports, etc.) to provide data both timely and correctly to them. An analysis of European AIRAC Non-adherence events led to the following classification:

  • Non-awareness among stakeholders of the importance of sticking to the AIRAC rules.
  • Insufficient planning and co-ordination (nationally, bilateral among neighbouring states and even international).
  • Correction of timely but incorrect earlier publications.
  • Variable and slow communication means. Even at state level, information is communicated in varying formats, using different (read: paper = slow) communication means which introduces delays. This can be further aggravated by the need for translation from national to any other publication languages and printing/distribution delays.
  • Postal Delay. Surprisingly enough, the average European postal delay of any Amendment is three (!) weeks. This makes a mockery of the two week allowance planned in the AIRAC regulations.
  • Monitoring and Regulation. There is no (centralised) monitoring/policing body. It is the States' own responsibility to adhere to AIRAC.
  • The occasional 'force majeure'.

Solutions

With the huge variety of causes, the 'solutions' vary for each different organisation. States are already doing a lot about it (awareness campaigns, training, national regulations, etc.). However, this has proven to be insufficient to eradicate the problem. In spite of its name, EUROCONTROL does not control AIRAC. It is merely acting on behalf of its Member States and so any activity can only be to assist the States. The activities are therefore concentrated on:

  • Monitoring, as you can only improve what you measure. Participation in pTracker provides the necessary data to monitor the AIRAC adherence.
  • Creating awareness on the problem, the consequences, the causes and the solutions is a continuous activity and has in the meantime addressed itself to many different fora.
  • Facilitation of publication dates, (links to) advanced and late publications, points of contacts. Key hereby is the internet based AIS AGORA which has proven to be the central place for 'Voicing problems and Sharing solutions'. It is further assisted by National AIRAC Publication Review and the @is online.

There is evidence to believe that campaigns to date have been reasonably successful in the European region. From a particularly bad 1999 with many last minute publications & cancellations (followed by many users bitterly complaining), the situation has now changed to being somewhere between a nuisance and a minor issue (and the users, including IATA, have started to express this as well). The number of AIRAC Non-adherence events is pretty stable but major events seem to have disappeared and/or at least have been anticipated and mitigated through AIS AGORA. So, do not be mistaken, more is still required and one should remain highly vigilant as it only takes one major late Amendment and the situation is back to where it started from.

Possible ways to solve the problem

ISO 9000

Since 1998, ICAO Annex 15 explicitly requires AIS organisations to implement a Quality Management System (QMS). Any such QMS enforces the formalisation of all incoming, processing and outgoing processes. This in itself, is a big step towards as it forces organisations to structure their activities. Within Europe all States have adopted the implementation of an ISO9000 system (further enforced by a EUROCONTROL ECIP Objective). This is well underway, but no QMS in the world can stop people violating the AIRAC rules.

EAD

The European AIS Database (EAD) is the prime source of European aeronautical information and contains mechanics to hinder publications violating the AIRAC rules. This is a major step forward. However, States remain solely responsible for the publication of their aeronautical information and will so always be able to 'bypass'.

Electronic AIP

Any electronic publication (and the electronic AIP (eAIP)electronic Aeronautical Information Publication (Phase 2 P-11) more in particular as it will allow the data to be electronically downloaded/interpreted) allows faster distribution of the data and so reduces the distribution delays. Although many states publish now on web and/or CD-ROM often liability and copyright issues remain to be solved.

What can be done?

  • Spread the word AIRAC (use, re-use anything of this web page, inform all your colleagues etc.) and the importance of adherence;
  • Participate to AIS AGORA and post any planned and/or (potential) late publication;
  • Verify your postal delays and monitor your own AIRAC adherence results in pTracker.

More Information?

  • ICAO Annex 15, Doc 8126 (specifically Chapter 4, AIRAC)