Introduction
Because of the limited character set supported by the AFTN network, NOTAM messages are constrained to be transmitted in full uppercase. This section presents an number of discusses issues related to this limitation, in particular from a human factors point of view, and discusses how the digital . It also explains how Digital NOTAM can provide more user friendly text outputs by applying the appropriate mix of uppercase and lowercase text.
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However, information to operational personnel in preparation of a flight is provided throughout the Pre-flight Information Bulletin (PIB) in full upper case format, because this is how NOTAM are received through AFTN. A PIB can be a document of 10 pages or more., written in full upper case!
The American Institute for Research (AIR) performed on behalf of the Federal Aviation Administration (FAA) of the USA studies during 2007-2009
addressing challenges associated with the NOTAM system. The objective was to identify and eliminate human performance barriers and hence to improve safety. The studies were performed by gathering information from commercial airline pilots, commercial airline dispatchers and general aviation pilots’ pilots on their user experience of with NOTAM messages.
The studies identified that the formatting of the NOTAM makes them difficult to read and understand by pilots. It highlighted issues concerning uppercase text and translation of abbreviations and acronyms. These factors were considered making the NOTAM difficult identified as causing difficulties to read NOTAM and process it, increasing the workload and the possibility of error. Amongst Among the items on the pilots’ wish-list for improvement in processes and functionality when using NOTAM data the following were identified:
- To to have digitized NOTAM data to would enable sorting and filtering of messages and translation into multiple formats, e.g. ICAO NOTAM format, plain language and graphical representation.
- To to improve the NOTAM format by e.g. reducing/eliminating the use of contractions (abbreviations and acronyms) and the use of capital letters in the free text.
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The use of uppercase in the traditional ICAO NOTAM is due to the character set limitations of the Aeronautical Fixed Telecommunication Network (AFTN). Digital NOTAM are not constrained by this AFTN limitation and a conventional mix of uppercase and lowercase can be used when generating the Event NOTAM text. The distribution of Digital NOTAM can be made through other networks than AFTN and can be used directly for enhanced PIB (ePIB). For legacy users, the Event Digital NOTAM text can be automatically converted into the ICAO format (all uppercase), thus satisfying the constraints AFTN transmission and for the traditional ICAO Pre-flight Bulletin (PIB) briefing.
In order to achieve an optimum mix of uppercase and lowercase text in the digital NOTAM output, styling rules for the digital NOTAM decoding templates need to be specified. While sentence case [1] formatting will be used in general, for abbreviations and acronyms the use of upper case can improve the readability of the information.
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The Single European Sky ATM Research and Development programme (SESAR) delivery “Generic SESAR Information Presentation Guide” [2]
from 2013 provides guidance on how to achieve an effective information presentation for the main actors involved in the ATM field. It provides guidance on presenting information:
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Pilots’ ideas on how briefing applications could support identifying abbreviations in the ePIB and display the explanation on less known abbreviations/acronyms were collected. This allowed the digital NOTAM text to be enhanced with mark-up elements, so that briefing tools/applications can identify abbreviations and offer either pop-up explanations or full expansion of less known abbreviations.
2.6 Within the AIS Stakeholders’ working arrangements of EUROCONTROL, the AI Operations Sub-group discussed during 2012 the usage of abbreviations in NOTAM. The Sub-group prepared input to ICAO proposing to indicate in ICAO Document 8400 (Abbreviations and Codes)
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It was proposed to spell out abbreviations and acronyms which are not common and can be subject to misinterpretation. Also, with the digital NOTAM developments in mind (e.g. no AFTN constraints), words such as “closed”, “available”, “activation”, “active”, “activated” and “unserviceable” were proposed to be spelled out instead of using the abbreviations. However, many abbreviations were recognised to be kept, such as “RWY”, “TWY”, “ILS”, “VOR”, “ATS”, since their meaning is so well known and the abbreviation/acronym is perceived as a word.
2.7 The EUROCONTROL Pre-digital NOTAM Templates document
applies to a certain extent the principle of spelled out text in item E on words such as “closed”, “available”, “activation”, “active”, “activated” and “unserviceable”, and on acronyms that are not commonly known.
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OTHER Aspects
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- Use of NOTAM for NIL digital data set notifications
o Does it make sense to use NOTAM in order to correct a data set? The information could be used by technical / operational support, not by the end user (pilot). However, that should not appear in the briefing package, because the change will be done by the
Reference documents
[1] Some of the listed abbreviations are in fact acronyms, e.g. “ACC”, but are included as in this case part of the family of air traffic services types.
[PE3]This rule means that acft is written like this, if not spelled out, which does not improve readability.
[PE4]Except for when used in lat/long values (according to OPADD)
[1]Sentence case: the standard capitalisation of a sentence with the first letter uppercase and subsequent letter lowercase with exceptions such as proper nouns or acronyms.
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