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AIS-AIMSG/76-SN/9
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International Civil Aviation Organization / AIS-AIMSG/6 SN/9
22/5/12

AERONAUTICAL INFORMATION SERVICES-AERONAUTICAL

INFORMATION MANAGEMENT STUDY GROUP (AIS-AIMSG)

SIXTH MEETING

Buenos Aires, 7 to 11November 2011

Agenda Item 6:Aeronatuical information and data assembly, exchange, and promulgation
6.2: NOTAM/SNOWTAM/ASHTAM

NOTAM PROLIFERATION

(Presented by Steven Hill UK CAA)

SUMMARY
The Purpose of this paper is to make Study Group members aware of the proliferation of NOTAM in circulation, and of the UK CAA activities which will seek to put in place a more robust NOTAM promulgation process. In addition, the paper seeks the support for activities to be undertaken by ICAO in order to address what is a global issue.

1.INTRODUCTION

1.1Quality aeronautical information and data has been recognized as an important enabler for the Global ATM System, and the AIS-AIM SG is working to enhance and refine Annex 15 so that it includes the Standards and Recommended Practices (SARPS’s) necessary to support that system. This activity fits in with the performance improvement areas defined under the Aviation Safety Block Upgrade strategy (ASBU) which includes Digital aeronautical information management as an area of focus.

1.2The AIS-AIM SG work will develop and propose amendments to SARP’s along with new or revised guidance material, and it will be for the State regulators to put in place the mechanism necessary to enable compliance. While this activity will see new practices for information management being adopted there are some current practicesthat will need to come under closerscrutiny by regulators.

1.3From the statistics available, the number of international NOTAM distributed annually between 2000 and 2011 has tripled, and the trend only shows an upwards trajectory. This increaseputs greater pressure on the end user or their NOTAM provider during the NOTAM filtering stage and the risk of not identifying important information becomesfar greater. Within the UK there are calls from industry for some activity to be undertaken to address what is seen as a significant issue. Instead ofbeing an importantsupplement to published ‘static’ information, if unchecked, the continuing increase in NOTAM being distributed could potentiallybe an inhibitor to Flight Safety.

2.DISCUSSION

2.1Chapter 3 of Annex 15 describes the responsibilities of the Contracting State and the including;

‘3.1.1.2 Each Contracting State shall take all necessary measures to ensure that the aeronautical information/data it provides relating to its own territory, as well as areas in which the State is responsible for air traffic services outside its territory, is adequate, of required quality and timely. This shall include arrangements for the timely provision of required information/data to the aeronautical information service by each of the State services associated with aircraft operations.’

And functions of the AIS, such as;

‘3.1.5 An aeronautical information service shall promptly make available to the aeronautical information services of other States any information/data necessary for the safety, regularity or efficiency of air navigation required by them, to enable them to comply with 3.1.6 below.

3.1.6 An aeronautical information service shall ensure that aeronautical information/data necessary for the safety regularity or efficiency of air navigation is made available in a form suitable for the operational requirements of:

a) those involved in flight operations, including flight crews, flight planning and flight simulators; and;

b) the air traffic services unit responsible for flight information service and the services responsible for pre-flight information.’

2.2From Annex 15 we can see that the State has a responsibility to ensure that the formal arrangements and mechanism are in place and which enable the AIS to fulfil its role using aeronautical data/information provided by responsible parties identified in National policy.

2.3Chapter 5 of Annex 15 describes the purpose and scope of NOTAM, the opening paragraph of thischapter indicates that;

5.1.1 A NOTAM shall be originated and issued promptly whenever the information to be distributed is of a temporary nature and of short duration or when operationally significant permanent changes, or temporary changes of long duration are made at short notice, except for extensive text and/or graphics.

2.4NOTAM may be proposed by a wide range of individuals, and some NOTAM may be submitted directlyto the NOTAM Office for publication such as those submitted by Aerodrome Operators or Airspace Managers. There are other NOTAM whose production will be managed by a StateAirspace Utilisation section where an approval or some coordination activity is required, such as for firework displays, military exercise etc.

2.5Statistics collected from the European Aeronautical Information Database (EAD) since the start of the millennium, clearly show a steady increase in NOTAM publication. From the data provided we can see thatapproximately 300,000 international NOTAM were published in 2000, and by the end of 2011 this increased to well over 800,000. The statistics at hand are for NOTAM distributed internationally, however, it is reasonable to assume that domestic NOTAM distribution has increased by a not dissimilar rate.

2.6In the UK alone, NOTAM publication (International and Domestic) increased from 32,000 in 2008, to 41,500 in 2011, an increase of 9,500 over a 4 year period.

2.7Without conducting an in-depth study, NOTAM by NOTAM, it would be difficult to understand precisely why this increase is occurring. The statistics available may allow an analysis of NOTAM distributed per ‘series’, and this will be undertaken at a later date. However, an un-scientific analysis indicates that the key issue which is most likely to be contributing to this increase in NOTAM publication is the relaxation of NOTAM publication criteria.

2.8Being more specific, some of the problems identified are listed here:

a)the use of UFN – This allows the NOTAM to exist until cancelled, the sponsor need not think about an end date, and therefore does not need to consider replacing the NOTAM. They may eventually cancel the NOTAM if they remember or are reminded.

b)NOTAM lasting longer than 90 days – Sponsors seeking the longest period of existence for a NOTAM, and, again removing the responsibility to consider an appropriate end date or replacing the NOTAM at the 90 day point.

c)the use of several NOTAM to address one subject matter – i.e. multiple closures of taxiways at the same airport.

d)Trigger NOTAM which remain valid for long periods after the event has been initiated.

e)The use of NOTAM to notify aerial activities that, when taking account of the rules of the air could be seen as routine.

2.9This initial sample, when considered as a whole, show several traits – in particular that the NOTAM sponsor has met their obligations by notifying ‘something’, and, by not identifying a specific end date, the responsibility to consider cancelation or replacement is ignored. Looking at these two facts together, we can see a trend developing;

NOTAM content + UFN = sponsor responsibilities met.

2.10This approach to meeting responsibilitymay be one of the main causes of the significant increase in the number of NOTAM now in circulation. While this approach may have mitigated some of the individual sponsor risk, it is likely to have merely shifted the risk elsewhere.The increase in published NOTAM gives the end users, including pilots, Airspace Managers or Flight Operations staff, a significant problem, and this is the sheer number of NOTAM which need to be filtered and analysed.

2.11Airlines, commercial service providers and some AIS providers have in place sophisticated software which will allow a certain level of filtering, often based on the activity, height/altitude and timing. However, the Q Code system, developed in 1909 and adopted for use in 1913, is one of the critical though limiting filtering mechanisms. It is unlikely that an attempt to replace the current NOTAM system with something more relevant to the 21st century will be successful; therefore initial efforts must be made to address current NOTAM promulgation practises.

2.12Within Europe, Eurocontrol, working with European Member States, have developed and initiated the Digital NOTAM concept. Once implemented the dNOTAM will show a vast improvement in NOTAM formatting and allow the NOTAM to be fully machine readable. This activity is well underway though while it will provide for better NOTAM submission and managementtechniques it will not inhibit the serial NOTAM sponsor.

2.13Difficulties encountered when trying to manage and analyse the ever increasing quantities of NOTAM are causing a concern amongst UK airlines and the General Aviation community. Equally the UK CAA has its own concerns, similar to those being expressed by industry.

2.14In July 2012, UK CAA will host and chair a NOTAM WG which will seek to identify UK specific issues, and to define and implement best practise within our NOTAM productionprocess. This group will have a two year sunset clause and CAA will share its findings with other interested parties. While this activity may result in a more robust NOTAM management and oversight practices in the UK, it will have little impact on the global issue.

3.CONCLUSION

3.1From the evidence available, the proliferation of NOTAM is clearly a global issue. Not all of the facts are known, and further work needs to be conducted to investigate, identifyand mitigate the causes where possible.

3.2With the number of NOTAM currently in circulation, there is a growing risk that a vital piece of information will be missed, and that a flight safety incident will occur. This is a risk that must be addressed, though this is something that a UK based working group alone cannot resolve.

3.3Further work should be undertaken by individual States to investigate how the NOTAM promulgation and distribution process is being managed. Ideally, and in order to maximise the benefit of the knowledge gained, this activity should be coordinated by ICAO under the auspices of a formal working group.

4.ACTION BY THE AIS-AIMSG

4.1The AIS-AIMSG is invited to:

a) note the information in this paper;

b)promote State level activity to investigate reasons for the increase in published NOTAM, and to identify, promote and implement best practise; and

c) consider the best method of coordinating these activities through ICAO.

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