The temporary outage of structure lighting associated with an obstacle.


  • this scenario covers the outage of lighting associated with existing obstacles that are lighted;
  • this scenario does not cover other status changes to existing obstacles/obstructions.

Event data

The following diagram identifies the information items that are usually provided by a data originator for the temporary outage of obstacle lighting.

EBNF code
input = "obstacle type" [description] [group] [mobile] \n
["location remarks"] ["obstacle identification"] \n
[position] "lighting status = UNSERVICEABLE" \n
"start time" "end time" [schedule] \n
[note] {"affected aerodrome"} {"affected FIR"}.

The table below provides more details about each information item contained in the diagram. It also provides the mapping of each information item within the AIXM 5.1 structure. The name of the variable (first column) is recommended for use as label of the data field in human-machine interfaces (HMI).

Data item


AIXM mapping

obstacle type

A type of vertical structure. The item is used alone or in combination with other attributes in order to identify the obstacle concerned.

VerticalStructure.type and VerticalStructure/VerticalStructurePart.type

descriptionA textual description of the obstacle, such as the number of similar items for a group, etc. The item is used alone or in combination with other attributes in order to identify the obstacle concerned.VerticalStructure.annotation with propertyName="type" and purpose="DESCRIPTION"


An indication whether Digital NOTAM refers to a group of obstacles with similar height located in close proximity to one another, coded as a single VerticalStructure 


An indication whether the obstacle has no fixed position.

VerticalStructure/ with this list of values CodeYesNoType

location remarks

A named geographical location where or close to which the obstacle is located (especially for Area 1 obstacles).

The item is used alone or in combination with other attributes in order to identify the obstacle concerned.

VerticalStructure/VerticalStructurePart.annotation with propertyName='horizontalProjection_location' and purpose="REMARK"

AIXM 5.1 workaround

In AIXM 5.1, the _ character is not allowed in the pattern for propertyName, therefore, when using AIXM 5.1, the propertyName has probably been left empty..

obstacle identificationAn alphanumerical designator by which the obstacle is identified in the national obstacle


The latitude, longitude and possibly the horizontal reference datum associated with the obstacle position.

The item is used alone or in combination with other attributes in order to identify the obstacle concerned.

VerticalStructure/VerticalStructurePart/ElevatedPoint or ElevatedSurface or ElevatedCurve

lighting status

The status of the obstacle warning lights.


Only the value 'UNSERVICEABLE' is supported in this scenario.


A schedule might be provided, in case the obstacle is only active according to a regular timetable, within the period between the start of life and the end of life.

VerticalStructure/VerticalStructureLightingStatus/Timesheet/... according to the rules for {{Schedules}}

start time

The effective date & time when the temporary change of an obstacle's light status starts. This might be further detailed in a "schedule".



Event/EventTimeSlice.validTime/beginPosition and Event/EventTimeSlice.featureLifetime/beginPosition

end time

The effective date & time when the temporary change of an obstacle's light status ends.



Event/EventTimeSlice.validTime/endPosition and Event/EventTimeSlice.featureLifetime/endPosition also applying the rules for Events with estimated end time


A free text note that provides further details about the obstacle lighting status.

VerticalStructure/VerticalStructureLightingStatus.annotation with purpose='”REMARK'

affected aerodrome

A reference (name, designator) to one or more airports/heliports that for which the establishment of the obstacle light outage has an operational relevance and needs to be notified to the users thereof.

affected FIR

A reference (type, designator) to one or more airspace of type FIR, for which the obstacle light outage has an operational relevance and needs to be notified.

Notethe FIR within which the obstacle is physically situated does not need to be provided by the data originator. It will be automatically identified by the application that enables the coding of the Event. If an additional FIR is specified by the originator, the application should check the plausibility of this data based on the FIR boundary. 



  • It is recommended that data input applications allow the operator to visualise graphically the position and extent of the obstacle, overlaid on an airport map or on an FIR map, as appropriate. If a schedule is used, the graphical interface should also have a "time slider" that allows the operator to see when the obstacle is actually effective.

Assumptions for baseline data

  • It is assumed that the obstacle data exists in the form of a VerticalStructure 'BASELINE' and it was coded as specified in the Obstacle Data Set coding guidelines.

Data encoding rules

The data encoding rules provided in this section shall be followed in order to ensure the harmonisation of the digital encodings provided by different sources. The compliance with some of these encoding rules can be checked with automatic data validation rules. When this is the case, the number of the encoding rule is mentioned in the data validation rule.


Data encoding rule


The temporary outage of the obstacle/obstruction lighting shall be encoded as:

  • a new Event, for which PERMDELTA and subsequent BASELINE TimeSlice (scenario='OBL.UNS, version='2.0') shall be created; and
  • a TimeSlice of type TEMPDELTA for the affected VerticalStructure feature, for which the "event:theEvent" property shall point to the Event instance created above.


If the obstacle lighting system is limited to a discrete schedule within the overall time period between the “start time” and the “end time”, then it shall be encoded using as many as necessary timeInterval/Timesheet properties for the VerticalStructureLightingStatus of the VerticalStructure TEMPDELTA Timeslice. See the rules for Event Schedules.


According to the AIXM Temporality Concept, the VerticalStructureLightingStatus elements included in TEMPDELTA completely replace all BASELINE VerticalStructureLightingStatus information, during the time of applicability of TEMPDELTA. Therefore, if the modified operational status only concerns certain times, the other times when the obstacle lighting system remains in the same status as in the BASELINE data shall be explicitly included in the TEMPDELTA. 

All VerticalStructureLightingStatus elements that are copied from the BASELINE data for completeness sake shall get an associated Note with purpose='REMARK' and the text='Baseline data copy. Not included in the NOTAM text generation'. This is based on the current NOTAM practice which consists of including in the NOTAM only the changed information and not explicitly including the static data that remains valid during the NOTAM applicability. It is recommended that the input interface provides a "calendar/level" view of the lighting status, enabling the operator to graphically check the status at different times 

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