[2.0] [NAV.UNS] Navaid unserviceable (NOTAM)

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 general production rules for item A using the concernedAirspace(s) or the concernedAirportHeliport, according to the rules specified in table above.

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

As general rules, for each NOTAM  that is generated:

• If Item A contains the designator of one (or more) FIR, insert E.

• If Item A contains the ICAO code of an AirportHeliport, insert AE, for the first such NOTAM and value A for the rest of the NOTAM.

However, more specific rules may be applied, depending on the split in NOTAM series, actual configuration of the FIR, etc. These have to be taken into consideration for each implementation.

Lower limit/Upper limit

The default values "000/999" shall be inserted.

Geographical reference

According to OPADD 4.1, item 2.3.12:

• if the NOTAM scope is A, then the coordinates shall be derived from the ARP of the related concerned AerodromeHeliport  
• if the NOTAM scope is E or AE, then the coordinates shall be derived from the NAV.BL position. If the NAV.BL does not have a specified position, then the position of one of its primary components NEQ.BL  shall be used.

Insert these values in the geographical reference item, formatted as follows:

• • the set of coordinates comprises 11 characters rounded up or down to the nearest minute; i.e. Latitude (N/S) in 5 characters; Longitude (E/W) in 6 characters. The radius consists of 3 figures rounded up to the next higher whole Nautical Mile; e.g. 10.2NM shall be indicated as 011.

Concerning the radius, according to OPADD 4.1, item 2.3.13.6:

• if the NOTAM scope is A, then the default value '005' shall be used
• if the NOTAM scope is E or AE, then the default value '025' shall be used. Note that a NOTAM operator might change this default value based on operational circumstances, as indicated in the OPADD 4.1 document. 

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" "NAV.TD.NavaidOperationalStatus.annotation(9)" "."] \n
{"\n" "NAV.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)").