Surface Characteristics [SCH]
- Wolfgang Scheucher
- georgiana.andrei04
- POROSNICU Eduard
AIXM Model Overview
An entity grouping together the attributes that model characteristics of an airport surface (e.g. Runway or TLOF), such as strength, material, etc.
The composition attribute is used to code the type of the predominant material of which a surface of the movement area is composed.
The preparation technique(s) applied to a surface composition are coded by the preparation attribute.
The quality of the surface of an airport surface will be coded with the surfaceCondition attribute.
AIXM 5.2 Improvements
A change proposal (AIXM-338) for the next AIXM 5.2 version has been approved by the AIXM Change Control Board, which adds new codes and refine definitions for existing codes in the codelist for CodeSurfaceConditionBaseType.
The coding guidelines provided here are aligned with forward/backward conversion rules contained in the AIXM-338 Change Proposal.
AIXM 5.2 Improvements
A change proposal (AIXM-319) for the next AIXM 5.2 version has been approved by the AIXM Change Control Board, which adds new codes in the codelist for CodeSurfaceCompositionBaseType.
The coding guidelines provided here are aligned with forward/backward conversion rules contained in the AIXM-319 Change Proposal.
Coding guidelines
Pavement Classification Number (PCN)
The Pavement Classification Number (PCN) is composed by 5 attributes:
- classPCN
The bearing strength of a pavement for unrestricted operations. - pavementTypePCN
The pavement behaviour (rigid or flexible) used for determining the Pavement Classification Number (PCN). - pavementSubgradePCN
An indication of the pavement subgrade strength related to the Pavement Classification Number (PCN). - maxTyrePressurePCN
The maximum allowable tire pressure category related to the Pavement Classification Number (PCN), as a category. - evaluationMethodPCN
The method used to rate a runway pavement.
The figure below gives an example of a PCN specification:
If the bearing strength of a rigid pavement, resting on a medium strength subgrade, has been assessed by technical evaluation to be PCN 80 and there is no tire pressure limitation, then the reported information would be as follows:
Load Classification Number (LCN)
The classLCN is used to code the value, which denotes the peak bearing moment the surface can handle repeatedly without shortening its service life.
Single Isolated Wheel Load (SIWL)
Two attributes are used to describe the Single Isolated Wheel Load (SIWL).
The weightSIWL attribute represents the maximum calculated load on each tire of a landing gear assembly that a movement area surface can support.
The tyrePressureSIWL attribute represents the maximum aircraft tire pressure that a movement area surface can support.
All Up Weight (AUW)
The weightAUW attribute represents the maximum total value of the weight of an aircraft that a movement area surface may support, regardless of the landing gear configuration of the aircraft.
Coding Rules for Surface Characteristic
| Identifier | Data Encoding Rule | Justification | Data Verification Rule (UID) | Remarks |
|---|---|---|---|---|
| SCH-101 | If classPCN is specified, then pavementTypePCN, pavementSubgradePCN, maxTirePressurePCN, evaluationMethodPCN must be specified. | ICAO Annex 14 | Draft rule 97DB0 | |
| SCH-102 | As a plausibility rule, the value of classPCN should be lower than 200. | ICAO Annex 14 | Draft rule 979C8 | |
| SCH-103 | As a plausibility rule, the value of classLCN should be lower than 200. | ICAO Annex 14 | Draft Rule 98968 | |
| SCH-104 | If weightSIWL is specified, then tyrePressureSIWL must be specified. | ICAO Annex 14 | draft rule 99138 |