[2.0] [OBL.UNS] Obstacle lights 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 VST.BL indicates that the corresponding data item must be taken from the VerticalStructure BASELINE;
• the abbreviation VST.TD indicates that the corresponding data item must be taken from the VerticalStructure TEMPDELTA that was created for the Event.
  • Important note: According to encoding rules for OBL.UNS, the TEMPDELTA might also include VerticalStructureLightingStatus 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 VerticalStructureLightingStatus 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!

In general, the ICAO DOC 8126 and the OPADD rules shall be followed. These have not been copied in this document in order to avoid duplication with those documents. Only instructions that are specific to the AIXM encoding of this event are stated here.

Several NOTAMs possible

Note that if an obstacle is located in the vicinity of one or more airports or affects more than one FIR, explicit associations between the Event and one or more AirportHeliport 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

Q code

Always use: QOLAS

Scope

Identify as described in Several NOTAM possible section above. 

Lower limit/Upper limit

For Scope E NOTAMs the highest descendant elevation value of all VST.BL.part.VerticalStructurePart, shall be used as Upper limit and '000' as Lower limit. This value shall be formatted according to the OPADD rules for 'LOWER/UPPER' qualifiers and rounded up to the nearest 100ft increment.

For Scope A or AE NOTAM, the default values "000/999" shall be inserted.

Geographical reference

According to OPADD 4.1, item 2.3.13.6:

• for a single structure, the radius is 001 is used and the coordinates are derived from the VST.BL.part.VerticalStructurePart.horizontalProjection position
• for multiple structures (geometry of type Curve of Surface), calculate the center and the radius (in NM) of a circle that encompasses the whole obstacle.

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.

See also the Note with regard to the risk that the circle/radius does not encompass the whole area, as discussed in the Location and radius common rules for the NOTAM text generation.

Items B, C and D

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

If at least one VST.TD.VerticalStructureLightingStatus.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 = "Obstacle lights" "VST.TD.VerticalStructureLightingStatus.status(1)" "on" ["VST.BL.group(2)"] ["VST.BL.part.mobile(3)"] "VST.BL.type(4)" \n
["(" "VST.BL.annotation(5)" ")"] ["located at" "VST.BL.annotation(6)"] ["identified as" "VST.BL.name(7)"] "VST.BL.part.horizontalProjection(8)" "." \n
 "elevation" "VST.BL.part.horizontalProjection.elevation(9)" ["(" "height" "VST.BL.verticalExtent(10)" ")"] "." \n
{"VST.TD.VerticalStructureLightingStatus.annotation(11)" "."}. 

Note: The objective is to fully automate 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 [archived] 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 "AL", 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 = "Obstacle lights" "on" ["VST.BL.group(2)"] ["VST.BL.part.mobile(3)"] "VST.BL.type(4)" ["(" "VST.BL.annotation(5)" ")"] \n
["located at" "VST.BL.annotation(6)"] ["identified as" "VST.BL.name(7)"] "VST.BL.part.horizontalProjection(8)" ("returned to service" | " : New NOTAM to follow(12)").