Restrictions
The coding guidelines for the ICAO Data Sets include general coding rules for Schedules [PWS]. These are also applicable to Digital NOTAM Events. However, more restrictive rules apply to NOTAM schedules, such as excluding the possibility to use 'HOL' and other special dates. These limitations lead to a smaller number of coding patterns for Digital NOTAM Event schedules, which are presented in this section.
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Supported schedules
There are three types of schedules supported for Digital NOTAM Events:
- daily schedules;
e.g. "daily from 09:00 to 17:00"; - date based schedules, including "on date" and "date range" options;
e.g. "1/10 09:00-15:00 and on 3/10 10:00-12:00"; - days of the week based schedules, including "on weekday", or "from weekday...to weekday" options;
e.g. "every Monday from 13:00 to sunset".
Not supported schedules
Combining different schedule types in a single NOTAM is forbidden. It is considered that such combined schedules could become too complex for being understood and would have a high potential for providing conflicting information. For example, "daily 0900-1700 and each MON 1900-2300" would not have a clear meaning. Is the schedule for Mondays just 1900-2300, or is it both 0900-1700 and 1900-2300? Therefore, such combined schedules are not supported.
Note that the concept of "weekday ranges" (such as "MON-WED") is also not supported in this specification. However, the automatic NOTAM generation rules for item D ensure that a set of consecutive weekdays with a similar start/end time will generate a "weekday range", according to the OPADD recommendations. This does not exclude implementing an HMI that allows the input of weekday ranges, for efficiency reasons. They will have to be converted into individual weekday records in AIXM.
Also not supported are schedules that use both startTime and StartEvent or both endTime and endEvent, such as "SR or 07:00, whichever is earliest". Such schedules are sometimes encountered for static data, as they need to cover longer time periods. It is not justified to use such combinations in a NOTAM schedule.
In addition, according to the OPADD, item D is not allowed to exceed 200 characters. The application interface should check the length of the item D that results from the schedule encoding and invite the operator to split the NOTAM into two separate events in case this limit is exceeded. The HMI should allow copying a draft event into a second draft event.
UML class diagrams representation
The limitations identified above correspond to a subset of the general AIXM model for schedules. The following UML diagram shows only the classes and properties which may be used for Digital NOTAM coding. For reference, the full AIXM schedules model is described here: AIXM - Schedules).
The data type or the sub-sets of allowable values that may be used in a Digital NOTAM encoding are shown in the following diagram:
TEMPDELTA - additional versus complete hours
As explained in the general coding rules for schedules - Relation with TimeSlice validity, a TEMPDELTA shall contain a complete description of the operating times.
Schedules are usually used when encoding availability or activation information, such as in the SAA.ACT, RTE.CLS, AD.CLS, etc. scenarios. In this situation, it is recommended that the input interface provides a "calendar/level" view of the activation/availability, enabling the operator to graphically visualise the status of the feature different times and levels (if applicable), such as in the example below:
In the calendar view, the BASELINE information that remains valid during the Event validity time shall be visibly identified from the information that is specific to the Event, for example by using a different color and fill pattern.
The TEMPDELTA shall contain the complete definition of the activity times, including any eventual time ranges that are recuperated from the BASELINE schedules. Note that according to the OPADD, notification of a schedule modification by NOTAM shall be done by including the new schedule in item E, not in item D. Therefore, the list of Event Scenarios has to include separate scenarios for such situations.
Common coding patterns
The Common coding patterns apply also for Digital NOTAM Event schedules, but with the limitations specified below.
"Daily" and "above. This means that only two types of schedules can be used in Digital NOTAM Events - "Daily/date based" or "Weekday based"
"Daily/date" based schedules
Refer to the Common coding patterns "Daily" schedules diagram.The following additional coding rules apply:
each use of "daily", "on date", "date range", "on weekday", or "from weekday...to weekday" shall be encoded as a single Timesheet, according to the [TSH] and [/TSH] indications in the diagrams;This applies to schedules that occur every day or on specific dates during the validity period of the data, without distinction between weekdays. However, it is possible to exclude specific dates from the applicable times of the schedule. For example:
- "daily from 09:00 to 17:00"
- "from 09 until 16 SEP and on 18 SEP, daily from SR until 18:00" (note that this would require two separate Timesheets, one for 9-16 SEP and one for 18 SEP, as it is not possible to specify multiple startDate/endDate on a single Timesheet).
- "daily from 07:00 to 23:00 except for 25 Dec and 1st Jan"
The data input elements that are specified for such schedules are indicated in the diagram below:
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Input_Daily_Date = "[TSH]" (("start date" "end date") | "on date" | "daily") ("start time" | ("start event" ["rel. start"])) ("end time" | ("end event" ["rel. end"])) {note} "[/TSH]" { "[TSH]" (("start date" "end date") | "on date" | "daily") ("start time" | ("start event" ["rel. start"])) ("end time" | ("end event" ["rel. end"])) {note} "[/TSH]"} \n
{"[TSH]" "excluded date" {note} "[/TSH]"} {"schedule note"}. |
The following table provides the mapping of each information item within the AIXM 5.1.1 structure. The name of the variable (first column) is recommended for use as label of the data field in human-machine interfaces (HMI).
Data Item | Coding | Comments |
|---|---|---|
[TS] and [/TS] | All the elements that appear between [TS] and [/TS] are encoded as a single timesheet | |
start date | Timesheet.startDate | |
end date | Timesheet.endDate | |
| on date | Timesheet.startDate and Timesheet.endDate | "on date" needs to be coded with both startDate and endDate having the same value, unless there is a full day (00:00 to 24:00) in which case the convention for "end of day' needs to be applied and the endDate gets the value of the next date after the startDate. |
| daily | Timesheet.startDate = NIL and Timesheet.endDate = NIL | |
start time | Timesheet.startTime | |
start event | Timesheet.startEvent | |
relative start | Timesheet.startTimeRelativeEvent | Positive values indicate that the actual start time is after the event. |
end time | Timesheet.endTime | |
end event | Timesheet.endEvent | |
relative end | Timesheet.endTimeRelativeEvent | Positive values indicate that the actual end time is after the event. |
note | Timesheet.annotation | Examples of such notes: |
excluded date | Timesheet with excluded='YES', |
startDate |
equal the "excluded date", endDate equal to "excluded date +1 day", day='ANY', startTime='00:00', |
endTime='00:00', timeReference='UTC+/-X' (local time as UTC zone). | |
schedule note | Note |
associated with the class that owns the schedule, with propertyName='timeInterval' and purpose='REMARK'. |
"Days of the week" based schedules
Refer to the Common coding patterns "Days of the week" schedules diagram.
Data verification rules
The data verification rules provided in this section shall be followed in order to ensure the harmonisation of the digital encodings provided by different sources. These rules shall be used as complementing the General coding rules for Schedules defined in AIXM Coding Overview - Common Coding Rules - Common coding patterns. In case of contradiction, the rules described below are superseding the general ones.
| Identifier | Data encoding rule | Remarks (column to be deleted at the end) |
|---|---|---|
| TSH.EVT-01 | Any Timesheet that is part of a TimeSlice associated with an Event that isNotifiedBy NOTAM shall have timeReference='UTC' | In NOTAM is mandatory to use UTC times only. |
| TSH.EVT-02 | Any Timesheet that is part of a TimeSlice associated with an Event that isNotifiedBy NOTAM shall have daylightSavingAdjust='NO' | In NOTAM it is not allowed to use auto-adjusted summer time values. |
| TSH.EVT-03 | Any Timesheet that is part of a TimeSlice associated with an Event that isNotifiedBy NOTAM and that has assigned values for startDate and endDate, must have day equal-to 'ANY'. | In NOTAM it is not possible to mix date ranges with week days. |
| TSH.EVT-04 | Any Timesheet that is part of a TimeSlice associated with an Event that isNotifiedBy NOTAM cannot use 'WORK_DAY', 'BEF_WORK_DAY', 'AFT_WORK_DAY', 'HOL', 'BEF_HOL', 'AFT_HOL' and 'BUSY_FRI' as day or dayTill values. | HOL and similar are not allowed in NOTAM schedules |
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| new | The startTimeRelativeEvent@uom cannot be other-than 'MIN' | proposed by Indra/Avitech, based on OPADD 4.1, section 2.3.20.2 |
| new | The endTimeRelativeEvent@uom cannot be other-than 'MIN' | proposed by Indra/Avitech, based on OPADD 4.1, section 2.3.20.2 |
| new | The startTimeRelativeEvent value cannot be higher-than 99 | proposed by Indra/Avitech, based on OPADD 4.1, section 2.3.20.2 |
| new | The endTimeRelativeEvent value cannot be higher-than 99 | proposed by Indra/Avitech, based on OPADD 4.1, section 2.3.20.2 |
| new | It is not allowed to have both startTime and startEvent in the same Timesheet | following comments made in the decoding scenarios |
| new | It is not allowed to have both endTime and endEvent in the same Timesheet | following comments made in the decoding scenarios |