[NAV.UNS] Navaid unserviceable (NOTAM)

Text NOTAM production rules

This section provides rules for the automated production of the text NOTAM message items, based on the AIXM 5.1 data encoding of the Event. Therefore, AIXM specific terms are used, such as names of features and properties, types of TimeSlices, etc:

• the abbreviation NAV.BL. indicates that the corresponding data item must be taken from the Navaid BASELINE, which is valid at the start time of the Event;
• the abbreviation NAV.TD. indicates that the corresponding data item must be taken from the Navaid TEMPDELTA;
• the abbreviation NEQ.BL. indicates that the corresponding data item must be taken from the NavaidEquipment BASELINE, which is valid at the start time of the Event;
• the abbreviation NEQ.TD. indicates that the corresponding data item must be taken from the NavaidEquipment TEMPDELTA;
• Important note: According to encoding rule ER-11, the TEMPDELTA might also include NavaidOperationalStatus elements that have been copied from the BASELINE data for compliance with the AIXM Temporality rules. The current practice is to not include such static information in the NOTAM text. Therefore, all NavaidOperationalStatus that have an associated annotation with purpose=REMARK and the text="Baseline data copy. Not included in the NOTAM text generation" shall be excepted from the text NOTAM generation algorithm!

Several NOTAMs possible

Note that if the navaid is used for instrument approach or departures from one or more airports or affects the en-route navigation in one or more FIR, explicit associations between the Event and one or more AirportHeliport and/or Airspace may be coded. Then, there exist dedicated provision in the OPADD (v4.1, section 2.3.9.3) with regard to the NOTAM that need to be issued in order to ensure that the NOTAM appear correctly in the relevant en-route and airport Pre-Flight Information Bulletins (PIB). Further details are provided in the “several NOTAM possible” section.

The NOTAM production rules provided on this page, unless specified otherwise, are applicable to the “first NOTAM” and the NOTAM containing one or more FIR in Item A. 

Item A

The item A shall be generated according to the geographical location of the Airspace and shall contain the Airspace.designator of the predefined FIR(s) for which a NOTAM has to be issued, except if there is an association Event to an AirportHeliport case in the AirportHeliport.designator shall be used. 

Item Q

Apply the common NOTAM production rules for item Q, complemented by the following specific rules for this particular scenario:

Q code

The mapping provided in the tables below shall be used.

and

Scope

Insert here AE. 

Items B, C and D

Items B and C shall be decoded from the values of NAV.TD.validTime following the common production rules.

If at least one NAV.TD.NavaidOperationalStatus.timeInterval exists (the Event has an associated schedule), then the associated Timesheets(s) shall be decoded in item D according to the common NOTAM production rules for {{Item D, E - Schedules}}. Otherwise, item D shall be left empty.

Item E

The following pattern should be used for automatically generating the E field text from the AIXM data: 

template = ["NAV.BL.name(1)"] "NAV.BL.type(2)" ["NEQ.BL.type(3)"] ["NEQ.TD.availability.signalType(4)"] [( "NAV.BL.designator(5)" | "RWY-" "NAV.BL.runwayDirection(5)")] \n ["NEQ.BL.frequency(6)"] ["NEQ.BL.channel(7)"] "NEQ.TD.operational status(8)" "." \n
["\n" "due to" "NEQ.TD.NavaidOperationalStatus.annotation(9)" "."] \n
{"\n" "NEQ.TD.NavaidOperationalStatus.annotation(10)" "."}.

Note: The objective is to full automatic generation, without human intervention. However, the implementers of the specification might consider reducing the cost of a fully automated generation by allowing the operator to fine-tune the text in order to improve its readability (with the inherent risk for human error, when re-typing is allowed).

Items F & G

Leave empty.

Event Update

The eventual update of this type of event shall be encoded following the general rules for Event update or cancellation, which provide instructions for all NOTAM fields, except for item E and the condition part of the Q code, in the case of a NOTAM C

If a NOTAM C is produced, then the 4th and 5th letters (the "condition") of the Q code shall be "AK", except for the situation of a “new NOTAM to follow", in which case “XX”shall be used.

The following pattern should be used for automatically generating the E field text from the AIXM data:

template_cancel = ["NAV.BL.name(1)"] "NAV.BL.type(2)" ["NEQ.BL.type(3)"] [( "NAV.BL.designator(5)" | "RWY-" "NAV.BL.runwayDirection(5)")] \n
["NEQ.BL.frequency(6)"] ["NAV.BL.channel(7)"] ("resumed normal operations." | " : New NOTAM to follow(11)").