Airfield Imaginary Surfaces

1
Airfield Imaginary Surfaces
Not to Scale
2
Runway
Runway dimensions are determined by each MAJCOM,
based on MDS. Runway orientation layout based on
prevailing winds and climatological studies (see
Chapter 2, UFC 3-260-01)
3
Primary Surface
Primary Surface (1000 Ft either side of
centerline)
For the purposes of determining obstacles on the
sides of the runway, the Primary Surface is
referenced horizontally to the runway ends and
vertically to the lowest threshold on the
facility. It extends 1000 feet from each
runway end and 1000 feet on either side of the
centerline.
1000 Ft
1000 Ft
1000 Ft
4
Zone of Frangibility
Zone of Frangibility
Mandatory for USAF, dimensions are 500 feet wide
centered on runway centerline, and the runway
length plus 6000 ft, centered on runway. All
items sited within this zone must be frangible
(read Attachment 14, UFC 3-260-01)
Runway Length 3000 feet (each end)
500 Ft
5
Transitional Surface (71)
The transitional surfaces extends outward
(perpendicular to centerline of runway) from
edge of primary surface 71 slope. Transitional
surface height stops at 150 feet, and stops
horizontally 3500 feet. 71 slope is 7H1V,
meaning for every 7 feet out, no one object can
be taller than 1 foot, 14 feet out 2 feet high,
etc.
150 Ft above the lowest threshold on the facility
Transitional
Primary
150 Ft
1 7 Slope
3500 Ft
4500 Ft
6
Inner Horizontal
The inner horizontal surface for each runway is
defined by 2 half circles centered on the runway
ends and joined by tangents. The radii of the
half circles is 7500 ft and the tangents are
parallel to the runway centerline at a distance
of 7500 feet. The surface is a constant 150 ft
above the height of the lowest threshold on the
facility.
150 ft above the height of the lowest threshold
on the facility.
7500 Ft
7500 Ft
7
Conical Surface
The inner edge of conical surface for each runway
begins at the outer edge of the inner horizontal
surface. Its outer edge is defined by 2 half
circles centered on the runway ends and joined by
tangents. The radii of the half circles is
14500 ft and the tangents are parallel to the
runway centerline at a distance of 14500 feet.
The surfaces extend 7000 feet horizontally and
are sloped at a 201 ratio. The outer edge is
500 ft above the height of the lowest threshold
on the facility.
500 Ft above lowest threshold on the facility
14500 Ft
14500 Ft
500 Ft
201 Slope
7500 Ft
7000 Ft
8
Outer Horizontal Surface
44500 Ft
44500 Ft
The Outer Horizontal surface begins at the outer
edge of the conical surface and extends outward
for 30000 feet. The outside of the outer
horizontal surface is 44500 ft from the runway
(14500 30000). Constant height of 500 ft above
the airfield.
500 Ft
9
Approach Departure Surfaces
501 Surface vertical reference is the height of
the runway end point
500 Ft above lowest point on airport
Part One
25000 ft
16,000 Ft
2,000 Ft
9,000 Ft
Part Two - Horizontal
25,000 Ft
501 Slope (blue) begins 200 feet from the runway
end For every 50 feet out, no obstructions can be
over 1 foot high, 100 feet out, 2 feet high,
etc. Slope continues until height of 500 feet,
then continues horizontally.
25,000 Ft
10
200 Ft
Primary Surface (1000 Ft Clear Zone)
Primary Surface (1000 Ft Clear Zone)
200 Ft
At the end of the runway
11
The 501 Slope Side View
500 Ft above the lowest threshold on the airport
EOR
501 Slope
Height of approach end
200 Ft
25,000 Feet
12
At the end of the runway
1000 Ft
1000 Ft
1000 Ft
200 Ft
13
1000 Ft
500 Ft above the lowest threshold on the airport
1000 Ft
1000 Ft
The 501 Slope
14
Total Horizontal length of Approach/Departure
Surface is 50,000 feet.
At the end of the runway Side View
500 Ft above the lowest threshold on the airport
EOR
Horizontal Portion (part two)
501 Slope
200 Ft
Sloped Portion (part one)
25000 Feet
25,000 Feet
15
500 Ft above the lowest threshold on the airport
1000 Ft
1000 Ft
25,000 Ft
1000 Ft
25,000 Ft
50,000 Ft
The flat approach departure surface
16
Approach Departure Surface
500 Ft Above lowest threshold on airport
501 Slope
25000 ft
25,000 Ft
16,000 Ft
2,000 Ft
Flat no slope
50000 ft
501 Approach Departure Surface begins 200 feet
from the runway end
17
Transitional Surface
71 Slope
501 Slope
18
Inner Horizontal Surface
501 Slope
71 Slope
19
Conical Surface
201 Slope
71 Slope
501 Slope
20
Outer Horizontal Surface
21
Airfield Imaginary Surfaces