[2.0] [RDD.CHG] Runway declared distances - change (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 RCP.TD. indicates that the corresponding data item must be taken from the RunwayCentrelinePoint TEMPDELTA that has been created for the Event;
the abbreviation RCP.TD.RDD. indicates that the corresponding data item must be taken from the associatedDeclaredDistance.RunwayDeclaredDistance of the RunwayCentrelinePoint TEMPDELTA that has been created for the Event;
the abbreviation RDN.BL. indicates that the corresponding data item must be taken from the RunwayDirection BASELINE associated with the RunwayCentrelinePoint;
the abbreviation RWY.BL. indicates that the corresponding data item must be taken from the Runway BASELINE associated with the RunwayDirection concerned;
the abbreviation AHP.BL. indicates that the corresponding data item must be taken from the AirportHeliport BASELINE associated with the Runway that is associated with the RunwayDirection concerned.

Note: It is assumed that all RunwayCentrelinePoint associated with the Event are also associated with the same Runway (through the RunwayDirection→ Runway association chain).

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 be generated according to the general production rules for item A using the Event.concernedAirportHeliport.

Q code

The following mapping shall be used:

Declared Distance	Corresponding Q code
Declared Distance Change	QMDCH

Scope

Insert the value ‘A’.

Lower limit / Upper limit

Use “000/999”

Geographical reference

Insert the coordinate of the ARP (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.

item D shall be left empty. Note: If the declared distances are associated with a schedule, this information will be provided in item E, next to the group of declared distances concerned. This is a different approach from the current NOTAM practice where the NOTAM user is left to integrate the information that remains valid from the baseline (AIP) data with the values provided by NOTAM. In this scenario, the NOTAM generated automatically from the AIXM coded data includes all declared distances, not only the changed values.

Item E

The following pattern should be used for automatically 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)")  ] "Declared distances changed as follows:" "\n" \n
"(4)" ["unpaved(5)"] "RWY.BL.type(6)" "RDN.BL.designator" ("(7)" "single declared distances group" | "multiple declared distances groups") "." {"(4)" "(4)" ["unpaved(5)"] "RWY.BL.type(6)" "RDN.BL.designator" ("(7)" "single declared distances group" | "multiple declared distances groups") "."} ["\n" "RCP.TD.annotation(16)" "."].
single_declared_distances_group = "(8)" "(9)" "RCP.TD.RDD.type(10)" "RCP.TD.RDD.declaredValue.RunwayDeclaredDistanceValue.distance(11)" {"(9)" "(9)" "RCP.TD.RDD.type(10)" "RCP.TD.RDD.declaredValue.RunwayDeclaredDistanceValue.distance(11)"}  ["RCP.TD.RDD.declaredValue.RunwayDeclaredDistanceValue.timInterval.Timesheet(12)"] "\n" {"(8)" "(8)" "(9)" "RCP.TD.RDD.type(10)" "RCP.TD.RDD.declaredValue.RunwayDeclaredDistanceValue.distance(11)" {"(9)" "(9)" "RCP.TD.RDD.type(10)" "RCP.TD.RDD.declaredValue.RunwayDeclaredDistanceValue.distance(11)"}  ["RCP.TD.RDD.declaredValue.RunwayDeclaredDistanceValue.timInterval.Timesheet(12)"] "\n"}.
multiple_declared_distances_group = "(13)" "\n" ["(14)" "(" "RCP.BL.designator" ")"] ["(15)" "(" "RCP.TD.RDD.annotation.Note" ")"] "single declared distances group" {"(13)" "(13)" "\n" ["(14)" "(" "RCP.BL.designator" ")"] ["(15)" "(" "RCP.TD.RDD.annotation.Note" ")"] "single declared distances group"}.

The item E production template is based on a number of loops that group and order the declared distances values, taking into consideration the current NOTAM practice:

by RunwayDirection concerned (if applicable), then
- by "runway alignment point" (if applicable, for runways directions that have more than one 'START_RUN' point), then
  - by similar schedule (if applicable)

The objective of this algorithm is to allow simple cases (one runway direction with one set of declared distances) to be output in the single line, for example "RWY 08 TORA 2800M TODA 2800M ASDA 2400M LDA 2300M", while more complex cases are also supported, but the text will inevitably be longer and more complex, such as in the following example:

"RWY 08L
LDA 2300M
TORA 2800M TODA 2800M ASDA 2400M
(TWY B) TORA 2000M TODA 2000M ASDA 1600M
RWY 26R
TORA 2800M TODA 2800M ASDA 2400M LDA 2400M (DAILY SR+30 SS-30)
TORA 2400M TODA 2400M ASDA 2400M LDA 2400M (DAILY SS-30 SR+30)"

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).

Reference

Data item (from coding scenario)

Rule

(1)

airport designator

If AHP.BL.locationIndicatorICAO is not null, 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)

airport name

a. 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)

runway direction

If more than one RCP.TD is associated with the Event, then group them ascending by associated RDN.BL.designator value. If more than one RDN.BL group is detected (more than one runway direction is concerned), then use the branch (4) for each RCP.TD group and repeat (4) until all groups are processed.

(5)

runway surface composition

Insert the word “unpaved” if RWY.BL.SurfaceCharacteristics.composition has one of the values 'CLAY', 'CORAL', 'EARTH', 'GRASS', 'GRAVEL', 'ICE', 'LATERITE', 'MACADAM', 'SAND', 'SNOW', 'WATER', 'OTHER'. Otherwise do not insert anything.

(6)

Insert here the type of the Runway decoded as follows

RWY.BL.type	Text to be inserted in Item E
RWY	"RWY"
FATO	"FATO"

(7)

centreline point designator

If in the RCP.TD group that is being processed (following rule #4) there is at maximum one RCP.TD.RDD descendant that has the same type value, then use the "single declared distances group". This is the typical case, when a single set of LDA, TORA, TODA, ASDA values are declared for a runway landing direction.

Otherwise, if two or more RCP.TD.RDD descendants have identical type values, then use the "multiple declared distances group" branch. In this case, there are additional "take-off alignment points" along the runway centreline, each with distinct values for TORA, TODA, LDA. It is unlikely that several LDA values exist for the same runway landing direction.

(8)

schedule

If there exist RCP.TD.RDD.declaredValue.RunwayDeclaredDistanceValue.timInterval.Timesheet (there is a schedule applicable to certain declared distances), then group the RCP.TD.RDD.declaredValue.RunwayDeclaredDistanceValue by identical timeInterval.Timesheet. Otherwise (no schedule), create just one group.

(9)

For each group of RCP.TD.RDD.declaredValue.RunwayDeclaredDistanceValue selected in rule (#8), order them by parent RCP.TD.RDD.type (in the order 'TORA', 'TODA', 'ASDA', 'LDA', 'TODAH', 'RTOAH', 'LDAH', other values...) and process each of them as indicated in the template

(10)

declared distance type

Insert here the declared distance type decoded as indicated below.

RCP.TD.RDD.type	Text to be inserted in Item E
TORA	"TORA"
TODA	"TODA"
ASDA	"ASDA"
LDA	“LDA”

RCP.TD.RDD.type	Text to be inserted in Item E
TODAH	"TODAH"
RTOAH	"RTODAH"
LDAH	"LDAH"

(11)

declared distance value

Insert here the declared distance value followed by its unit of measurement decoded according to the text NOTAM production rules for distances

(12)

schedule

Process the Timesheet of the group according to the NOTAM production rules for Item D, E - Schedules

(13)

declared distance type

Group the RCP.TD as follows:

first, by role in the order 'THR'/'DISTHR', 'START_RUN', other values;
second descending by RCP.TD.RDD.declaredValue.RunwayDeclaredDistanceValue.distance for type equal to 'TORA'

Then, process each group according to the template and repeat (loop #13) until all groups are processed.

(14)

If the RCP.BL.designator has a value, insert that value

(15)

centreline point location note

If the RCP.TD.RDD has an annotation.Note with propertyName equal to 'location', then translate it into free text according to the rule for annotations decoding

(16)

note

Annotations shall be translated into free text according to the rule for decoding annotations.

Items F & G

Leave empty.

Event Update

The eventual update of this type of event shall be encoded following the general rules for Event updates 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 NOTAMC

If a NOTAMC 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:

EBNF Code

template_cancel = ["(1)" "AHP.BL.type (2)" ("AHP.BL.name (3a)" | "AHP.BL.ARP (3b)")  ]  "(4)" ["unpaved(5)"] "RWY.BL.type(6)" "RDN.BL.designator" {"(4)" "(4)" ["unpaved(5)"] "RWY.BL.type(6)" "RDN.BL.designator"} ("resumed normal operations." | " : New NOTAM to follow.(17)").

Reference

Rule

(17)

If the NOTAM will be followed by a new NOTAM concerning the same situation, then the operator shall have the possibility to choose the "New NOTAM to follow" branch. This branch cannot be selected automatically because this information is only known by the operator.

Note: in this case, the 4th and 5th letters of the Q code shall also be changed into “XX”.