Introduction
For Runway Direction, PANS-AIM requires declared distances information as part of the minimum AIP data set. These are
...take off run available (TORA), take-off distance available (TODA), accelerate-stop distance available (ASDA), landing distance available (LDA)
The diagram below shows the AIXM classes, including the relevant data types (in green colour) needed to encode that information:
Conventional distances for a runway direction are maintained by using the RunwayDeclaredDistance class. Conventional distances encompass the following type:
- 'TORA' (Take-Off Run Available):
The length of the runway declared available and suitable for the ground run of an aeroplane taking off. - 'TODA' (Take-Off Distance Available):
The length of the TORA plus the length of the clearway, where provided. - 'ASDA' (Accelerate-Stop Distance Available):
The length of the TORA plus the length of the stopway, where provided. - 'LDA' (Landing Distance Available):
The length of runway which is declared available and suitable for the ground run of an aeroplane landing.
Where a runway has a displaced threshold, the LDA will be reduced by the distance the threshold is displaced, as shown in Figure below. A displaced threshold affects only the LDA for approaches made to that threshold; all declared distances for operations in the reciprocal direction may be unaffected.
The figure below illustrates the different types of declared distances for runway direction 26R.
Displaced threshold
In AIXM 5 the RunwayDeclaredDistance class is also used to encode the distance of the threshold displacement (i.e. from the physical start of the runway direction).
For this purpose the DeclaredDistance.type is encoded as 'DTHR'.
The actual displacement is encoded using the distance and distanceAccuracy attribute of the DeclaredDistanceValue class. This is a positive numerical value and it implies that the THR displacement is always inwards.
A declared distance is always related to a RunwayCentrelinePoint. For e displaced threshold the role of the related RunwayCentrelinePoint will be 'DISTHR'. (see also rules below).
TODA, TORA, ASDA, LDA
In AIXM 5 the DeclaredDistance.type is used to encode the type of a conventional operational distance declared for a runway direction.
The value of the distance declared is coded by using the RunwayDeclaredDistanceValue class. The attributes distance and distanceAccuracy are used for that purpose. According to PANS-AIM, the uom value used for the ValDistanceType for these attributes shall be either 'M' (Meters) or 'FT' (Feet) and no other value.
A declared distance is always related to a RunwayCentrelinePoint.
Depending on the DeclaredDistance.type, the related RunwayCentrelinePoint will have a certain role.
The table below gives an overview the type of a declared distances and the role of a runway centreline point that will usually be related to it.
DeclaredDistance.type | RunwayCentrelinePoint.role |
---|---|
'TORA' | 'START_RUN |
'TODA' | 'START_RUN' |
'ASDA' | 'START_RUN' |
'LDA' | 'THR' or 'DISTHR' |
Note
The position (latitude/longitude) of physical start of a runway direction ('START') or the position of the start of the take off run ('START_RUN') may not be known by the organisation publishing the AIP data set
- if the runway direction has a THR and the actual start of run position is not known, then it can be assumed that the THR is also the start run and then it is OK to encode the take-off distances in association with the THR
- however, if the runway direction has a displaced THR, then it is very unlikely that the 'TORA, TODA, ASDA' start from the DHTR position. Most likely they start from a point before the DTHR position. Therefore, in this case, it is proposed to always encode a separate 'START_RUN' point and associated the 'TORA, TODA, ASDA' with that point, If the exact position is not known, it should be left empty and a nilReason ('unknown') shall be provided. But it is anyhow more correct to encode it like this than to suppose that it starts at the DTHR position,
Declared Distance related to a Taxiway
Although not contained in PANS-AIM, the AIXM 5 model also supports the encoding of declared distances related to a Taxiway.
The relationship between the Taxiway and the RunwayDeclaredDistance is established via the GuidanceLine feature.
A RunwayCentrelinePoint has to be coded abeam where the corresponding Taxiway intersects with the Runway. The role will be 'START_RUN'. A RunwayDirection may have more than one RunwayCentrelinePoint of type equal-to 'START_RUN'.
A GuidanceLine will be coded that refers to the Taxiway and the RunwayCentrelinePoint.
The GuidanceLine.type which refers will be coded as 'TWY'. The GuidanceLine.desigantor should be the same as that of the connectedTaxiway.
AIP context
In some AIP this information is published, see example below.
Schedule for declared distances
Although not contained in PANS-AIM, the AIXM 5 model also supports the encoding of declared distances that change according to a schedule.
For example, the take-off distances at night might be shorter because of noise abatement reasons.
In some AIP this information is published, see example below.
AIP Context
In some AIP this information is published, see example below.
OPEN
How to code day or night with a timesheet.?
Declared distances for FATO
Although not required by PANS-AIM for the minimum AIP data set for teh FATO subject, AIXM 5 provides dedicated type values for helicopter operations:
- 'TODAH' (Take-Off Distance Available for Helicopters)
The length of the FATO plus the length of helicopter clearway (if provided) declared available and suitable for helicopters to complete the take-off. - 'RTODAH' (Rejected TODA for Helicopters)
The length of the FATO declared available and suitable for helicopters operated in performance class 1 to complete a rejected take-off. - 'LDAH' (LDA for Helicopters)
The length of the FATO plus any additional area declared available and suitable for helicopters to complete the landing manoeuvre from a defined height.
Coding Rules for Basic Data for Runway Direction
Identifier | Data Encoding Rule | Justification | Data Verification Rule (UID) | Remarks |
---|---|---|---|---|
RDN-108 | If Runway.type equal-to 'RWY' for each related RunwayDirection a RunwayDeclaredDistance.type equal-to 'TODA' shall be provided. | Minimum AIP data set | TBD | A runway exclusively used for landing operations may not have such a value. A nilReason equal-to 'inapplicable' and a corresponding Note should be provided. |
RDN-110 | If Runway.type equal-to 'RWY' for each related RunwayDirection a RunwayDeclaredDistance.type equal-to 'TORA' shall be provided. | Minimum AIP data set | TBD | A runway exclusively used for landing operations may not have such a value. A nilReason equal-to 'inapplicable' and a corresponding Note should be provided. |
RDN-111 | If Runway.type equal-to 'RWY' for each related RunwayDirection a RunwayDeclaredDistance.type equal-to 'ASDA' shall be provided. | Minimum AIP data set | TBD | A runway exclusively used for landing operations may not have such a value. A nilReason equal-to 'inapplicable' and a corresponding Note should be provided. |
RDN-112 | If Runway.type equal-to 'RWY' for each related RunwayDirection a RunwayDeclaredDistance.type equal-to 'LDA' shall be provided. | Minimum AIP data set | TBD | A runway exclusively used for take-off operations may not have such a value. A nilReason equal-to 'inapplicable' and a corresponding Note should be provided. |
RDN-127 | If Runway.type equal-to 'FATO' for the related RunwayDirection the RunwayDeclaredDistance.type shall not have assigned value other than ('TODAH', 'RTODAH', 'LDAH'). | Data consistency | TBD | |
RDN-113 | If Runway.type equal-to 'FATO' for each related RunwayDirection a RunwayDeclaredDistance.type equal-to 'RTODAH' shall be provided. | Minimum AIP data set | TBD | |
RDN-129 | If Runway.type equal-to 'RWY' for the related RunwayDirection the RunwayDeclaredDistance.type shall not have assigned value other than ('TODA', 'TORA', 'ASDA', 'LDA', 'DTHR'). | Data consistency | TBD | |
RDN-115 | For each RunwayDeclaredDistance a RunwayDeclaredDistance.declaredValue shall be provided. | PANS-AIM | TBD | |
RDN-115 | For each RunwayDeclaredDistanceValue.distance a RunwayDeclaredDistanceValue.distanceAccuracy shall be provided. | PANS-AIM | TBD | |
RDN-115 | Each RunwayDeclaredDistanceValue.distance.uom shall not have assigned value other than ('M', 'FT'). | PANS-AIM | TBD | |
RDN-115 | Each RunwayDeclaredDistanceValue.distanceAccuracy.uom shall not have assigned value other than ('M', 'FT'). | PANS-AIM | TBD | |
RDN-122 | For the same RunwayCentrelinePoint the RunwayDeclaredDistanceValue.distance (considering the uom information) of the 'TODA' must be equal with or greater than that of the 'TORA'. | EAD, Data consistency | TBD | |
RDN-123 | For the same RunwayCentrelinePoint the RunwayDeclaredDistanceValue.distance (considering the uom information) of the 'ASDA' must be equal with or greater than that of the 'TORA'. | EAD, Data consistency | TBD | |
RDN-124 | If RunwayDeclaredDistance.type is equal-to 'LDA', 'LDAH', 'TORA' or 'DTHR', the RunwayDeclaredDistanceValue.distance (considering the uom information) must be smaller than or equal to nominalLength of the related Runway. | EAD, Data consistency | TBD | |
RDN-131 | For the same RunwayCentrelinePoint the RunwayDeclaredDistanceValue.distance (considering the uom information) of the 'RTODAH' must be equal with or greater than that of the 'TODAH'. | EAD, Data consistency | TBD | |
RDN-142 | If coded, the value of the RunwayDeclaredDistanceValue.distance shall published with at least 1m or 1ft resolution. | PANS-AIM | TBD Note: the only think that can be verified in this case is the use of either FT or M as unit on measurement. A value such as "200 M" cannot be assumed to break this rule because maybe this is the exact elevation value. | |
RDN-143 | If coded, the value of the RunwayDeclaredDistanceValue.distanceAccuracy shall be 1 m or less. | PANS-AIM | TBD |
Coding Examples
Coding examples can be found in the DONLON AIXM 5.1.1 AIP data set file:
No. | Description | XPath Expression |
---|---|---|
RDN-EX-01 RCP-EX-01 | Runway direction, threshold, and declared distances | //aixm:RunwayDirectionTimeSlice[@gml:id ='RDN_EADD_09L'] | //aixm:RunwayCentrelinePointTimeSlice[@gml:id ='RCP_EADD_09L'] |
RDN-EX-02 RCP-EX-02 | Runway direction (incl. TDZ elevation), threshold, and declared distances (incl. displaced threshold). Note The data published in ICAO DOC 8216 for AIP specimen DONLON and in the corresponding eAIP specimen provided by Eurocontrol have been alteredin order to have an example for the encoding of a displaced threshold. | //aixm:RunwayDirectionTimeSlice[@gml:id ='RDN_EADD_27R'] | //aixm:RunwayCentrelinePointTimeSlice[@gml:id ='RCP_EADD_27R'] |
RDN-EX-03 RCP-EX-03 | Runway direction, threshold, and declared distances | //aixm:RunwayDirectionTimeSlice[@gml:id ='RDN_EADD_09R'] | //aixm:RunwayCentrelinePointTimeSlice[@gml:id ='RCP_EADD_09R'] |
RDN-EX-04 RCP-EX-04 | Runway direction, threshold, and declared distances | //aixm:RunwayDirectionTimeSlice[@gml:id ='RDN_EADD_27L'] | //aixm:RunwayCentrelinePointTimeSlice[@gml:id ='RCP_EADD_27L'] |
RDN-EX-05 RCP-EX-05 | FATO direction | //aixm:RunwayDirectionTimeSlice[@gml:id ='RDN_EADD_FATO_03'] | |
RDN-EX-06 RCP-EX-06 | FATO direction, threshold, and declared distances | //aixm:RunwayDirectionTimeSlice[@gml:id ='RDN_EADD_FATO_21'] | //aixm:RunwayCentrelinePointTimeSlice[@gml:id ='RCP_EADD_FATO_21'] |
RCP-EX-05 | Start Run for declared Distances from TWY B | //aixm:RunwayCentrelinePointTimeSlice[@gml:id ='RCP_EADD_TWY_B'] |
TWY-EX-01 | Taxiway B | //aixm:TaxiwayTimeSlice[@gml:id ='TWY_EADD_B'] |
GLN-Ex-01 | Guidanceline for Taxiway B | //aixm:GuidancelineTimeSlice[@gml:id ='GLN_EADD_TWY_B'] |