FAA FAR 77

Summary

Creates obstruction identification surfaces based on the FAA FAR 77 specification. These surfaces describe airspace segments that are clear of obstructions. The type, function, and dimension of a surface differs by runway classification. This tool creates surfaces as polygon or multipatch features, or triangulated irregular networks (TINs).

Usage

• The Input Runway Features parameter must be z-enabled.

• The selection you make in High Runway Designator Classification and Low Runway Designator Classification will automatically populate most of the surface parameters.

• This tool creates the OIS in an existing polygon or multipatch feature class. It can also be generated as a new TIN or polygon shapefile. If a feature class is selected for Output Features, it must have a vertical spatial reference.

• For military airports, the outer horizontal surface is merged as well as the horizontal and conical surfaces.

Syntax

arcpy.aviationois.FAAFAR77(in_features, high_runway_end_type, low_runway_end_type, specially_prepared_hard_surface_runway, highend_clear_way_length, lowend_clear_way_length, airport_elevation, include_merged_surface, out_features)

Parameter	Explanation	Data Type
in_features	The input runway dataset. The feature class must be z-enabled and contain points, polylines, or polygons.	Feature Layer
high_runway_end_type	The classification of the high end of the runway. CONSTRUCTION_OR_ALTERATION_ON_AN_AIRPORT_WITH_LONGEST_RUNWAY_MORE_THAN_3200_FEET —Construction on or alteration to a runway longer than 3,200 feet with an imaginary surface that extends outward 20,000 feet and has a slope that does not exceed 100 to 1. CONSTRUCTION_OR_ALTERATION_ON_AN_AIRPORT_WITH_LONGEST_RUNWAY_LESS_THAN_3200_FEET —Construction on or alteration to a runway less than 3,200 feet long with an imaginary surface that extends outward 10,000 feet and has a slope that does not exceed 50 to 1. CONSTRUCTION_OR_ALTERATION_ON_A_HELIPORT —Construction on or alteration to a heliport landing and takeoff area with an imaginary surface that extends outward 5,000 feet and has a slope that does not exceed 25 to 1. MILITARY_AIRPORT —Military airport runways are operated by an armed force of the United States. Primary surfaces are the same length as the runway. Primary surface width is 2,000 feet. Clear zone surface length is 1,000 feet and width is the same as the primary surface. The approach clearance surface starts 200 feet beyond each end of the primary surface and extends for 50,000 feet. Approach surface width matches the primary surface width at the runway end but flares to a width of 16,000 feet at an elevation of 50,000 feet. Approach clearance surface slope is 50 to I to an elevation of 500 feet above airport elevation. It then rises horizontally to 50,000 feet. Transitional surface slope is 7 to I outward and upward at right angles to the runway centerline. See section 77.28 in the FAR Part 77 specification for more information. NONPRECISION_INSTRUMENT_RUNWAY_GREATER_THAN_(>)_3/4_MILE_VISIBILITY —A runway with a nonprecision instrument approach procedure that allows for landing in visibility conditions greater than three-quarters of a mile. NONPRECISION_INSTRUMENT_RUNWAY_LESS_THAN_(<)_3/4_MILE_VISIBILITY —A runway with a nonprecision instrument approach procedure that allows for landing in visibility conditions less than three-quarters of a mile. PRECISION_INSTRUMENT_RUNWAY —A runway that uses Instrument Landing System (ILS) or Precision Approach Radar (PAR) for approach procedures. UTILITY_RUNWAY_VISUAL_APPROACH —A runway built for propeller aircraft not exceeding 12,500 pounds gross weight. Aircraft using the runway employ visual approach procedures. UTILITY_RUNWAY_NON_PRECISION_INSTRUMENT_APPROACH —A runway built for propeller aircraft not exceeding 12,500 pounds gross weight. The runway has an instrument approach procedure that uses air navigation facilities with horizontal guidance. It can also have area-type navigation equipment with approved nonprecision instrument approach procedures. VISUAL_RUNWAY_VISUAL_APPROACH —A runway that supports only visual approach procedures.	String
low_runway_end_type	The classification of the low end of the runway. SAME_AS_HIGH_RUNWAY_END_CLASSIFICATION —No low runway end type. NONPRECISION_INSTRUMENT_RUNWAY_GREATER_THAN_(>)_3/4_MILE_VISIBILITY —A runway with a nonprecision instrument approach procedure that allows for landing in visibility conditions greater than three-quarters of a mile. NONPRECISION_INSTRUMENT_RUNWAY_LESS_THAN_(<)_3/4_MILE_VISIBILITY —A runway with a nonprecision instrument approach procedure that allows for landing in visibility conditions less than three-quarters of a mile. PRECISION_INSTRUMENT_RUNWAY —A runway that uses Instrument Landing System (ILS) or Precision Approach Radar (PAR) for approach procedures. UTILITY_RUNWAY_VISUAL_APPROACH —A runway built for propeller aircraft not exceeding 12,500 pounds gross weight. Aircraft using the runway employ visual approach procedures. UTILITY_RUNWAY_NON_PRECISION_INSTRUMENT_APPROACH —A runway built for propeller aircraft not exceeding 12,500 pounds gross weight. The runway has an instrument approach procedure that uses air navigation facilities with horizontal guidance. It can also have area-type navigation equipment with approved nonprecision instrument approach procedures. VISUAL_RUNWAY_VISUAL_APPROACH —A runway that supports only visual approach procedures.	String
specially_prepared_hard_surface_runway	A specially prepared hard surface indicates that the primary surface extends 200 feet beyond each end of the runway. SPECIALLY_PREPARED_HARD_SURFACE_RUNWAY —The runway has a specially prepared hard surface. This is the default. NON_SPECIALLY_PREPARED_HARD_SURFACE_RUNWAY —The runway does not have a specially prepared hard surface.	Boolean
highend_clear_way_length	The length of the area at the high end of the runway, in feet. An aircraft can make a portion of its initial climb over this area.	Double
lowend_clear_way_length	The length of the area at the low end of the runway, in feet. An aircraft can make a portion of its initial climb over this area.	Double
airport_elevation	The highest point on any runway in an airport, in feet. The units for elevation are based on the specification. The tool will automatically populate this value from a z-value in your aeronautical database if you are using the AIS or Airports data model. Airport elevation is stored in the z-value of the ADHP point feature class in the AIS data model. In the Airports data model, elevation is stored in the z-value of the Airport Control Point feature class for records with the Point_Type field populated with AIRPORT_ELEVATION.	Double
include_merged_surface	Indicates whether merged horizontal and conical surfaces are included in the OIS, in addition to the regular surfaces. INCLUDE_MERGED_SURFACE —Include merged surfaces in the OIS output. This is the default. NOT_INCLUDE_MERGED_SURFACE —Do not include merged surfaces in the OIS output.	Boolean
out_features	The output feature class or TIN that will contain the generated obstacle identification surfaces.	Feature Layer; Folder

Code sample

FAAFAR77 example (stand-alone Python script)

The following Python window script demonstrates how to use the FAAFAR77 function.

import arcpy

# set gp environment
arcpy.env.workspace="c:/data/ois.gdb"
arcpy.CheckOutExtension("Aeronautical")

# Input Runway Feature Class
inFeatures = "RunwayCenterline"

# feature class that will contain the OIS surface
outFeatures="ObstructionIdSurface"

# runway variables
hiEndRunway = "Precision Instrument Runway"
lowEndRunway = "Precision Instrument Runway"
hardSurfaceRunway="SPECIALLY_PREPARED_HARD_SURFACE_RUNWAY"
hiEndClearWay=0
lowEndClearWay=0
airportElev = 0

# execute the tool
arcpy.FAAFAR77_aviationois(inFeatures,hiEndRunway,lowEndRunway,hardSurfaceRunway,
                        hiEndClearWay,lowEndClearWay,airportElev,
                        "INCLUDE_MERGED_SURFACE",outFeatures)
arcpy.CheckInExtension("Aeronautical")

Environments

• Current Workspace

Licensing information

• Basic: No
• Standard: Requires Airports or Aviation Charting
• Advanced: Requires Airports or Aviation Charting