North Dakota Administrative Code
Title 6 - Aeronautics Commission
Article 6-02 - Aeronautics Commission
Chapter 6-02-03.1 - AIRPORT RUNWAY APPROACH HAZARDS
Section 6-02-03.1-04 - Airport referenced imaginary surfaces

Universal Citation: ND Admin Code ยง 6-02-03.1-04

Current through Supplement No. 394, October, 2024

The following airport imaginary surfaces are established with relation to the airport and to each runway. The size of each imaginary surface is based on the classification of each runway and the type of approach available or planned for that runway. Refer to Exhibit A for a table showing the classification and dimensional standards. Refer to Exhibit B and C for a graphical depiction of the imaginary surfaces.

1. Primary surface. A surface longitudinally centered on a runway. When the runway has a specially prepared hard surface, the primary surface extends two hundred feet beyond each end of that runway; but when the runway has no specially prepared hard surface, or planned hard surface, the primary surface ends at each end of that runway. The elevation of any point on the primary surface is the same as the elevation of the nearest point on the runway centerline. The width of a primary surface is:

a. Two hundred fifty feet for utility runways having only visual approaches.

b. Five hundred feet for utility runways having nonprecision instrument approaches.

c. For other than utility runways the width is:
(1) Five hundred feet for visual runways having only visual approaches.

(2) Five hundred feet for nonprecision instrument runways having visibility minimums greater than three-fourths statute mile.

(3) One thousand feet for a nonprecision instrument runway having a nonprecision instrument approach with visibility minimums as low as three-fourths of a statute mile, and for precision instrument runways.

The width of the primary surface of a runway will be that width prescribed in this section for the most precise approach existing or planned for either end of that runway.

2. Approach surface. A surface longitudinally centered on the extended runway centerline and extending outward and upward from each end of the primary surface. An approach surface is applied to each end of each runway based upon the type of approach available or planned for that runway end.

a. The inner edge of the approach surface is the same width as the primary surface and it expands uniformly to a width of:
(1) One thousand two hundred fifty feet for that end of a utility runway with only visual approaches;

(2) One thousand fifty feet for that end of a runway other than a utility runway with only visual approaches;

(3) Two thousand feet for that end of a utility runway with a nonprecision instrument approach;

(4) Three thousand five hundred feet for that end of a nonprecision instrument runway other than utility, having visibility minimums greater than three-fourths of a statute mile;

(5) Four thousand feet for that end of a nonprecision instrument runway, other than utility, having a nonprecision instrument approach with visibility minimums as low as three-fourths statute mile; and

(6) Sixteen thousand feet for precision instrument runways.

b. The approach surface extends for a horizontal distance of:
(1) Five thousand feet at a slope of twenty to one for all utility and visual runways;

(2) Ten thousand feet at a slope of thirty-four to one for all nonprecision instrument runways other than utility; and

(3) Ten thousand feet at a slope of fifty to one with an additional forty thousand feet at a slope of forty to one for all precision instrument runways.

3. Horizontal surface. A horizontal plane one hundred fifty feet above the established airport elevation, the perimeter of which is constructed by swinging arcs of specified radii from the center of each end of the primary surface of each runway of each airport and connecting the adjacent arcs by lines tangent to those arcs. The radius of each arc is:

a. Five thousand feet for all runways designated as utility or visual;

b. Ten thousand feet for all other runways. The radius of the arc specified for each end of a runway will have the same arithmetical value. That value will be the highest determined for either end of the runway. When a five thousand-foot arc is encompassed by tangents connecting two adjacent ten thousand-foot arcs, the five thousand-foot arc shall be disregarded on the construction of the perimeter of the horizontal surface.

4. Conical surface. A surface extending outward and upward from the periphery of the horizontal surface at a slope of twenty to one for a horizontal distance of four thousand feet.

5. Transitional surface. These surfaces extend outward and upward at right angles to the runway centerline and the runway centerline extended at a slope of seven to one from the sides of the primary surface and from the sides of the approach surfaces. Transitional surfaces for those portions of the precision approach surface which project through and beyond the limits of the conical surface, extend a distance of five thousand feet measured horizontally from the edge of the approach surface and at right angles to the runway centerline.

General Authority: NDCC 2-03-12

Law Implemented: NDCC 2-03-12

Disclaimer: These regulations may not be the most recent version. North Dakota may have more current or accurate information. We make no warranties or guarantees about the accuracy, completeness, or adequacy of the information contained on this site or the information linked to on the state site. Please check official sources.
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