TM 5-823-4
b. Surfaces not requiring paint. If the smooth
end colored orange. The width of each band for
structures as high as 700 feet above ground level (AGL)
surface of paint on the ladders, decks and walkways of
should be approximately one-seventh of the height of the
certain types of steel towers and similar structures
structure.
Higher structures should be painted an
presents a potential danger to maintenance personnel,
additional orange and white band for each additional 200
such surfaces need not be painted. Care should be
feet of height, or fraction thereof, with the width of all
taken so the overall marking effect of the painting is not
bands equal and in proportion to the structure's height
reduced. Where the painting or the act of painting
above ground level. For example, it a structure is:
certain precision or critical surfaces would have an
adverse effect on the desired transmission or radiation
Greater Than
But Not Exceeding
Band Width
characteristics of a radio frequency signal, such painting
may be omitted.
10.5 feet
700 feet
1/7 of height of structure
c. Skeletal structures. Paint should be applied
700 feet
900 feet
1/9 of height of structure
to all surfaces both 'inner and outer, of the framework in
900 feet
1,100 feet
1/11 of height of structure
order to be effective. This applies to the supporting
1,100 feet
1,300 feet
1/13 of height of structure
structures of overhead transmission lines as well as
radio, television and similar skeletal structures.
If the top of the structure has a cover or roof, the top
orange band should be continued to cover the entire top
7-8.
Patterns. Patterns of various types are used to
of the structure. If the object under study is a flagpole,
mark obstructions to air navigation. Normally, the size
skeletal structure or similar object erected on top of a
and shape of the obstruction will determine the pattern to
building, the combined height of the object and building
be used.
will determine whether marking is recommended;
a. Solid pattern. An obstruction the projection
however, only the height of the object under study
of which on any vertical plane has both dimensions less
determines the width of the color bands.
than 10.5 feet, should be colored aviation surface
(b) Partial marking.
If marking is
orange.
recommended on only a portion of a structure because
b. Alternate bands of orange and white (figure
of shielding by other objects or terrain, the width of the
7-1). Alternate bands of aviation surface orange and
bands should be determined by the overall height of the
white are normally displayed on the following structures:
structure.
A minimum of three bands should be
(1) Radio and television towers and
displaced on the upper portion of the structure.
supporting structures of overhead transmission lines
c. Checkerboard pattern (figures 7-2 and 7-3).
(see paragraph 7-9a).
Checkerboard patterns of alternate rectangles of aviation
(2) Poles.
surface orange and white are normally displayed on:
(3) Smokestacks.
(1) Water, gas and grain storage tanks,
(4) Skeletal framework of storage tanks and
excluding skeletal framework.
similar structures.
(2) Buildings.
(5) Structures which appear narrow from a
(3) Structures which appear broad from a
side view.
side view, such as structures having a horizontal
(a) Width of bands. The width of bands for
dimension 10.5 feet or greater and this horizontal
structures of any height should be equal, provided that
dimensi6n is equal to or greater than the vertical
each band has a width of not more than 100 feet nor less
dimension.
than 1 feet. The bands should be perpendicular to the
vertical axis of the obstruction with the bands at each
Change 1 7-2
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