FAA FAR 77 (Aeronautical)
Summary
Creates obstacle identification surfaces based on the FAA FAR 77 specification. These surfaces describe airspace segments that are clear of obstacles. The type, function, and dimension of a surface differs by runway classification. This tool creates surfaces as polygon features.
Usage
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The production database must be defined in the Data Management pane of the Production Properties dialog box.
The Input Runway Features must be Z enabled.
The selection you make in Runway Classification will automatically populate most of the surface parameters. You can modify these existing preset values, but the generated geometry may not be valid. Default and preset values are defined from obstruction standards for civil airport imaginary surfaces.
Changing Linear Unit and Angular Unit will re-compute surface parameter values.
The tool does not create the Output Feature Class. You can specify the ObstacleArea feature class as the Output Feature Class. You can find the ObstacleArea feature class in your production database. The Output Feature Class must exist, be Z enabled, and have the same geometry type and fields as the ObstacleArea feature class.
The Output Feature Class must have a vertical spatial reference.
This tool always runs in foreground mode. If you run this tool with Background Processing checked on, the tool will automatically switch to foreground processing.
Syntax
Parameter | Explanation | Data Type |
in_features |
The input runway dataset. The feature class must be polyline or polygon. | Feature Layer |
input_feature_sql | A Structured Query Language (SQL) WHERE clause that selects a subset of features from in_features. | SQL Expression |
input_clear_way (Optional) |
The length of the area at the end of the take-off run. An aircraft can make a portion of its initial climb over this area. | Double |
input_runway_type |
The runway classification of the Input Runway Features (in_features).
| String |
input_airport_elevation |
The highest point on any runway in an airport. The Linear Unit parameter sets the units for reference elevation. The tool will automatically populate this value from a z value in your aeronautical database if you are using the 18b data model. | Double |
input_ois_unit |
The runway length linear unit of measurement.
| String |
input_ois_slope |
Angular unit of measurement for slope values.
| Long |
primary_surface | Toggles on/off generation of an imaginary surface longitudinally centered on a runway.
| Boolean |
primary_surface_length |
Primary surface length excluding the length of the runway. | Double |
primary_surface_width |
Primary surface width excluding the width of the runway. | Double |
conical_surface | Toggle on/off generation of a conical surface extending outward and upward from the periphery of the horizontal surface.
| Boolean |
conical_surface_slope | The slope of the conical surface. Slope measurement units are specified in the conical_surface_slope parameter. The default value is 20 (20:1) | Double |
conical_surface_offset | The length of the conical surface. Length measurement units are specified in the input_ois_unit parameter. The default value is 4000 feet. | Double |
horizontal_surface | Toggle on/off generation of the horizontal surface. This surface lies above the established airport elevation. The surface is defined by lines tangent to arcs at horizontal_surface_radius distance from the center of each end of the primary surface.
| Boolean |
horizontal_surface_radius | Double | |
horizontal_surface_height |
The height of the horizontal surface above the established airport elevation. The default is 150 feet. | Double |
approach_surface | Toggle on/off approach surface generation. The approach surface extends outward and upward from each end of the primary surface.
| Boolean |
approach_surface_extendedwidth |
The width of the approach surface outer edge. | Double |
first_section_length |
The length of the first section of the approach surface. | Double |
first_section_slope |
The slope of the first section of the approach surface. | Double |
second_section_length |
The length of the second section of the approach surface. | Double |
second_section_slope |
The slope of the second section of the approach surface. | Double |
transitional_surface | Toggle on/off transitional surface generation. The transitional surface extends upward and outward from the primary and approach surfaces. This surface ends where it intersects the horizontal surface.
| Boolean |
transition_surface_slope |
The slope of the transitional surface. The default is 7 (7:1). | Double |
output_feature_class |
The output feature class that will contain the generated obstacle identification surfaces. | Feature Layer |
Code Sample
The following Python window script shows an example of the FAAFAR77 function.
# Input Runway Feature Class - change this path infc = r'Database Servers\your_server_SQLEXPRESS.gds\ASP_PD (VERSION:dbo.DEFAULT)\ASP_PD.DBO.ADHPSurfaceLine' # Output Feature Class - this feature class must exist outfc = "C:\\data\\work.gdb\\ObstacleArea_FAAFar77" # Import the toolbox - verify this path exists arcpy.ImportToolbox(r'C:\Program Files\ArcGIS\Desktop10.0\ArcToolbox\Toolboxes\Aeronautical Tools.tbx') # exec FAA FAR 77 arcpy.FAAFAR77_Aeronautical(infc,"Objectid in (2)","0","Utility visual approach",2,"Feet","Rise (X:1)","CREATE_PRIMARY_SURFACE","200", "250","CREATE_CONICAL_SURFACE","20","4000","CREATE_HORIZONTAL_SURFACE","5000", "150","CREATE_APPROACH_SURFACE","100","1000","1","200","2","NO_CREATE_TRANSITIONAL_SURFACE","0",outfc)