[WIP][TWY.CLS] Taxiway - closure (NOTAM)

Text NOTAM production rules

This section provides rules for the automated production of the text NOTAM message items, based on the AIXM 5.1.1 data encoding of the Event. Therefore, AIXM specific terms are used, such as names of features and properties, types of TimeSlices, etc:

the abbreviation TWY.BL. indicates that the corresponding data item must be taken from the Taxiway BASELINE;
the abbreviation TWY.TD. indicates that the corresponding data item must be taken from the Taxiway TEMPDELTA that was created for the Event in case of complete taxiway closure;
the abbreviation TWE.TD. indicates that the corresponding data item must be taken from the TaxiwayElement TEMPDELTA that was created for the Event in case of taxiway portion closure;
the abbreviation AHP.BL. indicates that the corresponding data item must be taken from the AirportHeliport BASELINE associated with the Taxiway that is associated with the TaxiwayElement concerned;
- Note: According to encoding rules for TWY.CLS, the TEMPDELTA(s) might also include ManoeuvringAreaAvailability 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 ManoeuvringAreaAvailability 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.

Item A

The item A shall contain the AHP.BL.locationIndicatorICAO if not NIL. Otherwise, the nationality letter(s) as defined in ICAO Doc 7910 followed by “XX” or “XXX”.

Q code

The following mapping shall be used:

*Closure status*	*Corresponding Q codes*
CLOSED, if Taxiway.type other than FASTEXIT and there are no associated AirportHeliportUsage.type PERMIT or CONDITIONAL	QMXLC
CLOSED, Taxiway type other than FASTEXIT but there also exist associated AirportHeliportUsage.type PERMIT or CONDITIONAL	QMXLT
CLOSED, Taxiway type=FASTEXIT and there are no associated AirportHeliportUsage.type PERMIT or CONDITIONAL	QMYLC
CLOSED, Taxiway type=FASTEXIT but there also exist associated AirportHeliportUsage.type PERMIT or CONDITIONAL	QMYLT

Scope

Insert the value ‘A’.

Lower limit / Upper limit

Use “000/999”

Geographical reference

Insert the coordinate of the ARP (AHP.BL.ARP.ElevatedPoint) of the airport, 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 value is “005”.

Items B, C and D

Items B and C shall be decoded following the common production rules.

If at least one TWY.TD.availability.ManouevringAreaAvailability.timeInterval or TWE.TD.availability.ManouevringAreaAvailability.timeInterval exists (i.e. the Event has an associated schedule), then all such Timesheet(s) shall be represented 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 as a base for generating the E field text from the AIXM data:

EBNF Code

template = ["(1)" "AHP.BL.type (2)" ("AHP.BL.name (3a)" | "AHP.BL.ARP (3b)")] \n ("Rapid exit TWY(4)" | "TWY") "TWY.BL.designator(5)" {"closed_taxiway_portion(6)"}["and(7)"| ","] {("Rapid exit TWY(4)" | "TWY") "TWY.BL.designator(5)" {"closed_taxiway_portion(6)"} ["and(7)"| ","]}
\n "closed" [ "due to" "TWY/TWE.TD.availability.annotation (8)"]\n 
["(9)" "\n" "except" ["TWY/TWE.TD.usage.PPR(10)"] ["TWY/TWE.TD.usage.flight(11)"] ["TWY/TWE.TD.usage.aircraft(12)"]["flights"] {"(13)" "," ["TWY/TWE.TD.usage.PPR(10)"] ["TWY/TWE.TD.usage.flight(11)"] ["TWY/TWE.TD.usage.aircraft(12)"]["flights"]} ] \n
{"\n" "TWY/TWE.TD.availability.annotation(14)" "."} ["."].

Reference

Rule

(1)

If AHP.BL.locationIndicatorICAO=YES, then ignore this branch.

(2)

Insert here the type of the airport decoded as follows

AHP.BL.type	Text to be inserted in Item E
AD or AH	"AD"
HP	"Heliport"
LS or OTHER	"Landing site"

(3)

a. If AHP.BL.name is not NIL, then insert it here. Otherwise

b. insert here the text "located at" followed by the AHP.BL.ARP.ElevatedPoint decoded according to the text NOTAM production rules for aixm:Point.

(4)

if TWY.BLtype = FASTEXIT insert the words “Rapid exit". Otherwise insert "TWY".

(5)

If more than one Taxiway and/or TaxiwayElement has a TEMPDELTA associated with the Event, then insert the designator of each additional Taxiway, designator preceded by ",". Insert "and" before the last entry.

(6)

Insert here the TWY.annotation and/or TWE.annotation note with purpose="OTHER:DESCRIPTION" stored in the BASELINE data (e.g. “between TWY A and TWY B”).

If taxiway elements are used, the automatic generation of an easy human-readeable NOTAM text is practically impossible using just the AIXM encoding. Two cases can be identified for describing the closed taxiway portion:

Case 1: use long text from descriptions, as available in the TWE.annotation.

Example: Following the example of Fig.1 from coding rules, the text would look as follows: "between TWY B and TWY C, intersection TWY A and TWY C, between TWY C and TWY D”

Case 2: allow the operator to manually write the text part.

Since the operator is allowed to modify the item E text manually, the choice to simplify the text can be made. The result of manual editing could result in something as follows: "between TWY B and TWY D, including intersections between".

(7)

Insert "and" before the last taxiway or taxiway portion affected by the closure (e.g. "TWY A, TWY B and TWY C")

(8)

If there exists a TWY.TD.availability.annotation or TWE.TD.availability.annotation having propertyName="operationalStatus" and purpose="REMARK", then translate it into free text according to the decoding rules for annotations.

(9)

If there exist one or more TD.availability.usage then decode them following this branch, in the following order of priorities:

TD.availability.usage that have operation="ALL"
TD.availability.usage that have type="PERMIT"
... other situations ...
TD.availability.usage that have priorPermission which is not NIL shall be decoded last.

(10)

If TD.usage.priorPermission is not NIL, then insert here the decoding of the PPR information as detailed in the following diagram:

EBNF Code

template_PPR = "PPR " "TWY/TWE.TD.usage.priorPermission(10.1)" ["TWY/TWE.TD.usage.annotation(10.2)"].

Reference	Rule
(10.1)	Insert here the value of the priorPermission attribute followed by its unit of measurement decoded according to the {{text NOTAM production rules for duration}}
(10.2)	Decode here the annotation with propertyName="priorPermission" and purpose="REMARK", according to the decoding rules for annotations.

(11)

Decode here each FlightCharacteristics property that was specified, as detailed below. If more than one FlightCharacteristics property was used, insert blanks between consecutive properties.

FlightCharacteristics.type*	Text to be inserted in Item E
OAT	"Operational Air Traffic"
GAT	"General Air Traffic"
ALL	"Operational Air Traffic/General Air Traffic"
OTHER:MY_TEXT	"my text" (replace "_" with blanks)

*Note: type is unlikely to be used in a NOTAM, its decoding is provided for completeness sake.

FlightCharacteristics.rule	Text to be inserted in Item E
IFR	"IFR"
VFR	"VFR"
ALL*	"IFR/VFR"
OTHER:MY_TEXT	"my text" (replace "_" with blanks)