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 issues related to this limitation, in particular from a human factors point of view, and discusses how the digital NOTAM can provide more user friendly text outputs by applying the appropriate mix of uppercase and lowercase text.
Problems with uppercase text in NOTAM
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Existing guidelines and good practices
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To help specifying styling rules on usage of uppercase and lowercase in the NOTAM text, guidelines on information presentation in equipment and systems Human Machine Interface (HMI) exist as well as other experienced practices, presented in the following paragraphs.
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The Human Factors Integration Technical Guide 3.2. Equipment: Information presentation provides guidelines for information presentation, including usage of uppercase and lowercase. It states that information shall be presented such that it can be quickly located and understood by the intended users under operational conditions, and where size, spacing and styling of text shall be considered. Information shall be unambiguous and meaningful to the targeted user.
Specifying rules for character highlighting such as bright or bold characters, underlining characters, or slanting the text (italics) should be avoided, since the effect varies depending on the characters to which it is applied. This might also require the use of mark-up languages, which would unnecessarily complicate the Digital NOTAM Specification.
Where coding techniques are used, the meaning of codes shall as far as possible be based on associations which the user can be expected to be familiar. Words, names and abbreviations shall be based on language and terminology used by the targeted user.
Format, style and location of the information shall be applied consistently throughout the user’s overall task context, including other systems with which users can be expected to interact. This aspect is of interest when defining upper- or lowercase rules in the digital NOTAM for abbreviations and acronyms commonly used in ATM systems, such as RWY, TWY, THR, ILS and DME (compared to rwy, twy, thr, ils, dme).
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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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In a clear and unambiguous form.
- In a format that calls for the attention of the users.
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Lowercase enhances reading efficiency because word shape is helpful in word recognition. It is therefore recommended to use lowercase, which supports faster word recognition.
2.4 Further related to choice of fonts, the guidance states that text should be presented in a combination of uppercase and lowercase letters. Continuous text is easiest to read and comprehend when it is presented in mixed case letters and should also be used for messages, menu descriptions, button descriptions, or screen identification. Capitals should only be used for headlines, key phrases or acronyms, short items to draw the user’s attention to important text (for example, field labels or a window title), the first letter in a sentence, or a single character in each word in a title or label.
2.5 Similar input came from the SESAR ePIB project.
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Proposed approach
1.1 This section contains proposed rules for the use of a mix of upper and lower case in the Digital NOTAM Specification, part 3, “Decoding”. Theseruleswill apply to the text elements used in the templates for the NOTAM items E and also for the writing of the text in items D, F and G. It includes rules for the formatting of abbreviations and acronyms, with the purpose to provide a clear, meaningful and easy to read text for the user.
1.2 Uppercase characters shall always be used for:
The first letter in a sentence.
Each first letter of a name (such as 'Brussels South')
| Warning | ||
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This is not possible with AIXM 5.1 because all names are just in Upper Case, a limitation inherited from AIXM 4.5 where it was introduced exactly for facilitating the use of feature names in AFTN messages (such as NOTAM). To be raised as an issue in the AIXM CCB, to allow lower case in a future version. Maybe on the same issue discuss the problem of local language – using annotation type “Translation” Transitory solution: give an algorithm for converting Character3 data type into lower case. A proposal was developed by Michael Kadlec (Avitech) and will be included here. |
Each first letter of certain acronyms that are spelled out
Note: To be discussed to which acronyms this rule shall apply to avoid uppercase text such as “Climb To And Maintain”, “Feet Per Minute”, “TouchDown Zone”.
Note: acronyms to which this rule does not apply: airspace types (such as TRA - will be written "temporary restricted area"), etc.
Acronyms that are not spelled out (such as VOR, SID, NOTAM, AIP, etc.).
Location indicators.
Designators (such as five-letter ICAO designators for waypoint, navigation aid designators, route/SID/STAR designators, airspace designators, etc.).
Specified abbreviations (see paragraph 5.5).
1.3 Lowercase characters shall always be used for:
· Consecutive text after the first letter in a sentence.
· Abbreviations[PE3] , except those specifically mentioned as to be written otherwise.
· Spelled out abbreviations and acronyms.
1.4 Mix of uppercase and lowercase
· Unit of measurements shall be spelled in accordance with SI units.
1.5 Specific rules for abbreviations[1]
· The abbreviation and uppercase shall always be used for:
o RWY, TWY, THR, AWY, ATS, ARP and the different air traffic services types (e.g. AIS, FIS, AFIS, TWR, ACC, APP).
o Area types CTA, UTA, TMA, CTR, FIR and UIR.
o Days and months (MON, TUE, WED, THU, FRI, SAT, SUN, JAN, FEB, MAR, APR, MAY, JUN, JUL, AUG, SEP, OCT, NOV, DEC).
· Abbreviations that shall be spelled out:
o Single words such as “closed”, “unavailable”, “activated”, “between” with the exception of “AD”.
o Colours.
o Cardinal points and their combination.[PE4]
o Abbreviations/acronyms that are not commonly used, not included in ICAO Doc 8400 and/or may be subject to misunderstanding (e.g. use ‘area chart’ instead of “ARC”).
1.6 Digital NOTAM text examples with these applied rules:
· ILS/DME RWY 19 unserviceable.
· RWY 01 closed.
· Temporary Reserved Airspace ESTS310 activated.
· THR RWY 19 displaced 400m. Declared distances changed: TORA 2450m, TODA 2450m, ASDA 2450m, LDA 2050m.
· Trigger NOTAM – perm AIRAC amendment 02/14 WEF 20 FEB 2014: new ATS route M123 established.
· VOR DKB resumed normal operations.
· Danger Area HED9 activated.
· ATS operating hours changed as follows: 01 03 05 1000-1600 02 04 06-31 0800-2200.
· EGNOS is not available for LPV.
· AWY G5 closed between WIL and FRI.
· RNAV route N850 closed between GERSA and ODINA.
· Temporary Restricted Area Narnia established.
· Temporary restricted area Narnia established.
· Crane position 500545N 0141556E erected 190m south of RWY 13/31 axis, 1300m behind THR RWY 31, elevation 390.3m height 20.7m AGL.
· ILS RWY 25R unserviceable.
· TWY A east of RWY 10/28 closed.
· Minimum Sector Altitude southwest sector raised to 1700ft AMSL.
Discussion in the Focus Group:
- Doubts about ATC, they might not like the change from Upper case to sentence case. Therefore a warning could be added in the specification that the presentation of the NOTAM text to specific groups of users should be verified first. For pilots there is no doubt, they prefer sentence case (see ePIB). For users that prefer upper case only, the conversion in straight-forward.
OTHER Aspects
- NOTAM reason for closure or similar, are they really necessary in a NOTAM?
- 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.
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