TM 5-823-4
CHAPTER 7
MARKING OF OBSTRUCTIONS TO AIR NAVIGATION
necessary to color the structure or indicate its presence
7-1.
General. Obstructions to air navigation at all
by use of suitable markers, flags or lights.
airfields and heliports at Army installations will be marked
in accordance with FAA AC No.
70/7460-1G.
7-5.
Omission of standard marking. When high
Obstruction marking will be limited to those objects that
penetrate the clearance planes, and surfaces set forth in
intensity lighting systems are employed in accordance
TM 5-8034 and to those objects that, by their nature and
with the standards contained herein, the marking of
position constitute a hazard to air navigation. These
structures with standard aviation surface orange and
markings should be held to the minimum commensurate
white paint and red obstruction lights may by omitted.
with essential operational requirements. Obstruction
The high intensity lighting systems are considered to be
markings on objects that are not, in fact, obstructions,
far more effective than the aviation surface orange and
present false and misleading information and should be
white paint and may therefore be recommended in lieu of
eliminated.
standard marking. This is particularly true under certain
ambient light conditions and position of the sun relative
to direction of flight.
7-2.
Detail requirements.
Only those paint
materials will be used that meet the minimum standards
7-6.
Colors. Maximum visibility of an obstruction by
established by the FAA.
a. Color marking. Obstruction marking will be
contrast in colors can best be obtained by the use of
aviation surface orange and white paint. Orange or white
made with aviation surface orange, or a combination of
enamel paint may be used for marking, provided its
aviation surface orange and aviation surface white.
b. Marking materials. Obstructions will be
chromaticity and luminance factors satisfy Federal
Standard, color, as follows:
marked by the use of surface colors wherever
a. Orange. Number 12197 (aviation surface
practicable.
Surface colors will consist of paint
orange).
conforming to the Federal Specification, Military
b. White. Number 17875 (aviation white).
Specification, or Department of the Army, Corps of
Engineers, Guide Specifications for Military Construction
covering paint appropriate for the material being painted,
7-7.
Painting. The specifications of surface colors
or reflective tape conforming to Federal Specification
apply only to freshly painted surfaces. Paints used for
LS300.
Where marking by surface color is
surface markings usually change with time. While it is
impracticable, the general definition and location of the
not feasible to require strict maintenance, surfaces
obstructions will be indicated by suitable markers or flag.
should be repainted whenever the color changes
Aviation surface orange is defined as a color not darker
noticeably or its effectiveness is impaired by scaling or
than color chip No. 12197 nor lighter than color chip No.
chipping.
A color tolerance chart is available for
12246, as contained in Federal Standard No. 595.
determining when repainting is necessary. The lower
c. Application.
portion of structures situated in wooded or sheltered
(1) Painted markings will be applied to
areas are protected to some extent from direct sunshine,
obstruction surfaces only after care has been taken to
blowing sand and sleet, and other atmospheric and
insure that such surfaces are dry and clean.
environmental elements that tend to deteriorate painted
(2) Reflective tape will be applied
surfaces. Therefore, examination of the ground or
according to the manufacturer's instructions.
bottom band of aviation surface orange paint is not a
(3) When impracticable to apply the
good indication and should not be used as a criteria for
marking material directly to the top 5 feet of poles or
determining when repainting is necessary.
towers, supporting overhead or guy wires, the marking
a. Materials and application. Quality paint
material may be placed on a backlog surface,
materials should be selected to be compatible with the
longitudinally split tube or other mountable device and
surfaces to be painted, including previous coatings on
this may be attached directly to the poles or towers.
the surfaces if any, as well as suitable for the
environmental service conditions to which it will be
7-3.
Lighting
of
airfields,
heliports
and
subjected. Surface preparation and paint application
should be accomplished in accordance with the
obstructions.
For criteria on lighting or airfields,
manufacturer's recommendations as appropriate for the
heliports and obstructions, see TM 5-811-5.
paint to be used and surface to be coated.
7-4.
Purpose of marking. The purpose of marking a
structure is to warn airmen of its presence during
daylight hours. To accomplish this objective, it may be
Change 1 7-1
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