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SIGNALLING TECHNIQUES
One of your first concerns when you find yourself in a survival
situation is to communicate with your friends or allies.
Generally, communication is the giving and receiving
of information. As a survivor, you must get your rescuer’s
attention first, and second, send a message your rescuer
understands. Some attention-getters are man-made geometric
patterns such as straight lines, circles, triangles, or
X’s displayed in uninhabited areas; a large fire or flash of
light; a large, bright object moving slowly; or contrast,
whether from color or shadows. The type of signal used will
depend on your environment and the enemy situation.
APPLICATION
If in a noncombat situation, you need to find the largest
available clear
and flat area on the highest possible terrain. Use as obvious a
signal as you
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can create. On the other hand, you will have to be more discreet
in
combat situations. You do not want to signal and attract the
enemy. Pick
an area that is visible from the air, but ensure there are
hiding places
nearby. Try to have a hill or other object between the signal
site and the
enemy to mask your signal from the enemy. Perform a thorough
reconnaissance
of the area to ensure there are no enemy forces nearby.
Whatever signaling technique or device you plan to use, know how
to
use it and be ready to put it into operation on short notice. If
possible,
avoid using signals or signaling techniques that can physically
endanger
you. Keep in mind that signals to your friends may alert the
enemy of
your presence and location. Before signaling, carefully weigh
your rescue
chances by friends against the danger of capture by the enemy.
A radio is probably the surest and quickest way to let others
know where
you are and to let you receive their messages. Become familiar
with the
radios in your unit. Learn how to operate them and how to send
and
receive messages.
You will find descriptions of other signaling techniques,
devices, and
articles you can use. Learn how to use them. Think of ways in
which you
can adapt or change them for different environments. Practice
using
these signaling techniques, devices, and articles before you
need them.
Planned, prearranged signaling techniques may improve your
chance
of rescue.
MEANS FOR SIGNALING
There are two main ways to get attention or to communicate—
visual
and audio. The means you use will depend on your situation and
the
material you have available. Whatever the means, always have
visual
and audio signals ready for use.
Visual Signals
These signals are materials or equipment you use to make your
presence
known to rescuers.
Fire
During darkness, fire is the most effective visual means for
signaling.
Build three fires in a triangle (the international distress
signal) or in a
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straight line with about 25 meters between the fires. Build them
as soon
as time and the situation permit and protect them until you need
them.
If you are alone, maintaining three fires may be difficult. If
so, maintain
one signal fire.
When constructing signal fires, consider your geographic
location. If
in a jungle, find a natural clearing or the edge of a stream
where you
can build fires that the jungle foliage will not hide. You may
even have
to clear an area. If in a snow-covered area, you may have to
clear the
ground of snow or make a platform on which to build the fire so
that
melting snow will not extinguish it.
A burning tree (tree torch) is another way to attract attention
(Figure
1). You can set pitch-bearing trees afire, even when green. You
can get other types of trees to burn by placing dry wood in the
lower
branches and igniting it so that the flames flare up and ignite
the
foliage. Before the primary tree is consumed, cut and add more
small
green trees to the fire to produce more smoke. Always select an
isolated
tree so that you do not start a forest fire and endanger
yourself.
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Smoke
During daylight, build a smoke generator and use smoke to gain
attention
(Figure
2). The international distress signal is three columns
of smoke. Try to create a color of smoke that contrasts with the
background;
dark smoke against a light background and vice versa. If you
practically smother a large fire with green leaves, moss, or a
little water,
the fire will produce white smoke. If you add rubber or
oil-soaked rags
to a fire, you will get black smoke.
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In a desert environment, smoke hangs close to the ground, but a
pilot
can spot it in open desert terrain.
Smoke signals are effective only on comparatively calm, clear
days. High
winds, rain, or snow disperse smoke, lessening its chances of
being seen.
Smoke Grenades
If you have smoke grenades with you, use them in the same
pattern
as described for fires. Keep them dry so that they will work
when you
need them. Take care not to ignite the vegetation in the area
when
you use them.
Pen Flares
These flares are part of an aviator’s survival vest. The device
consists of
a pen-shaped gun with a flare attached by a nylon cord. When
fired, the
pen flare sounds like a pistol shot and fires the flare about
150 meters
high. It is about 3 centimeters in diameter.
To have the pen flare ready for immediate use, take it out of
its wrapper,
attach the flare, leave the gun uncocked, and wear it on a cord
or
chain around your neck. Be ready to fire it in front of search
aircraft and
be ready with a secondary signal. Also, be ready to take cover
in case the
pilot mistakes the flare for enemy fire.
Tracer Ammunition
You may use rifle or pistol tracer ammunition to signal search
aircraft.
Do not fire the ammunition in front of the aircraft. As with pen
flares,
be ready to take cover if the pilot mistakes your tracers for
enemy fire.
Star Clusters
Red is the international distress color; therefore, use a red
star cluster
whenever possible. Any color, however, will let your rescuers
know
where you are. Star clusters reach a height of 200 to 215
meters, burn
an average of 6 to 10 seconds, and descend at a rate of 14
meters
per second.
Star Parachute Flares
These flares reach a height of 200 to 215 meters and descend at
a rate
of 2.1 meters per second. The M126 (red) burns about 50 seconds
and
the M127 (white) about 25 seconds. At night you can see these
flares at
48 to 56 kilometers.
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Mirrors or Shiny Objects
On a sunny day, a mirror is your best signaling device. If you
don’t have
a mirror, polish your canteen cup, your belt buckle, or a
similar object
that will reflect the sun’s rays. Direct the flashes in one area
so that
they are secure from enemy observation. Practice using a mirror
or shiny
object for signaling now; do not wait until you need it. If you
have an
MK-3 signal mirror, follow the instructions on its back (Figure
3).
Wear the signal mirror on a cord or chain around your neck so
that it is
ready for immediate use. However, be sure the glass side is
against your
body so that it will not flash; the enemy can see the flash.
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CAUTION
Do not flash a signal mirror rapidly because a pilot may mistake
the flashes
for enemy fire. Do not direct the beam in the aircraft’s cockpit
for more than
a few seconds as it may blind the pilot.
Haze, ground fog, and mirages may make it hard for a pilot to
spot signals
from a flashing object. So, if possible, get to the highest
point in
your area when signaling. If you can’t determine the aircraft’s
location,
flash your signal in the direction of the aircraft noise.
Note: Pilots have reported seeing mirror flashes up to 160
kilometers away
under ideal conditions.
Figures
4 and
5 show methods of aiming a signal mirror for
signaling.
Flashlight or Strobe Light
At night you can use a flashlight or a strobe light to send an
SOS to an
aircraft. When using a strobe light, take care to prevent the
pilot from
mistaking it for incoming ground fire. The strobe light flashes
60 times
per minute. Some strobe lights have infrared covers and lenses.
Blue
flash collimators are also available for strobe lights.
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VS-17 Panel
During daylight you can use a VS-17 panel to signal. Place the
orange
side up as it is easier to see from the air than the violet
side. Flashing
the panel will make it easier for the aircrew to spot. You can
use any
bright orange or violet cloth as a substitute for the VS-17.
Clothing
Spreading clothing on the ground or in the top of a tree is
another way
to signal. Select articles whose color will contrast with the
natural surroundings.
Arrange them in a large geometric pattern to make them
more likely to attract attention.
Natural Material
If you lack other means, you can use natural materials to form a
symbol
or message that can be seen from the air. Build mounds that cast
shadows;
you can use brush, foliage of any type, rocks, or snow blocks.
In snow-covered areas, tramp the snow to form letters or symbols
and
fill the depression with contrasting material (twigs or
branches). In
sand, use boulders, vegetation, or seaweed to form a symbol or
message.
In brush-covered areas, cut out patterns in the vegetation or
sear the
ground. In tundra, dig trenches or turn the sod upside down.
In any terrain, use contrasting materials that will make the
symbols
visible to the aircrews.
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Sea Dye Markers
All Army aircraft involved in operations near or over water will
normally
carry a water survival kit that contains sea dye markers. If you
are in a
water survival situation, use sea dye markers during daylight to
indicate
your location. These spots of dye stay conspicuous for about 3
hours, except
in very rough seas. Use them only if you are in a friendly area.
Keep
the markers wrapped until you are ready to use them. Use them
only
when you hear or sight an aircraft. Sea dye markers are also
very effective
on snow-covered ground; use them to write distress code letters.
Audio Signals
Radios, whistles, and gunshots are some of the methods you can
use to
signal your presence to rescuers.
Radio Equipment
The AN/PRC-90 survival radio is a part of the Army aviator’s
survival
vest. The AN/PRC-112 will eventually replace the AN/PRC-90. Both
radios can transmit either tone or voice. Any other type of Army
radio
can do the same. The ranges of the different radios vary
depending on
the altitude of the receiving aircraft, terrain, vegetation
density, weather,
battery strength, type of radio, and interference. To obtain
maximum
performance from radios, use the following procedures:
Try to transmit only in clear, unobstructed terrain. Since
radios are
line-of-sight communications devices, any terrain between the
radio
and the receiver will block the signal.
Keep the antenna at right angles to the rescuing aircraft. There
is no
signal from the tip of the antenna.
If the radio has tone capability, place it upright on a flat,
elevated
surface so that you can perform other survival tasks.
Never let the antenna touch your clothing, body, foliage, or the
ground. Such contact greatly reduces the range of the signal.
Conserve battery power. Turn the radio off when you are not
using it.
Do not transmit or receive constantly. In hostile territory,
keep transmissions
short to avoid enemy radio direction finding.
In cold weather, keep the battery inside your clothing when not
using
the radio. Cold quickly drains the battery’s power. Do not
expose the
battery to extreme heat such as desert sun. High heat may cause
the
battery to explode. Try to keep the radio and battery as dry as
possible,
as water may destroy the circuitry.
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Whistles
Whistles provide an excellent way for close up signaling. In
some
documented cases, they have been heard up to 1.6 kilometers
away.
Manufactured whistles have more range than a human whistle.
Gunshots
In some situations you can use firearms for signaling. Three
shots
fired at distinct intervals usually indicate a distress signal.
Do not use
this technique in enemy territory. The enemy will surely come to
investigate shots.
CODES AND SIGNALS
Now that you know how to let people know where you are, you need
to
know how to give them more information. It is easier to form one
symbol
than to spell out an entire message. Therefore, learn the codes
and
symbols that all aircraft pilots understand.
SOS
You can use lights or flags to send an SOS—three dots, three
dashes,
three dots. The SOS is the internationally recognized distress
signal in
radio Morse code. A dot is a short, sharp pulse; a dash is a
longer pulse.
Keep repeating the signal. When using flags, hold flags on the
left side
for dashes and on the right side for dots.
Ground-to-Air Emergency Code
This code (Figure
6) is actually five definite, meaningful symbols.
Make these symbols a minimum of 1 meter wide and 6 meters long.
If
you make them larger, keep the same 1:6 ratio. Ensure the signal
contrasts
greatly with the ground it is on. Place it in an open area
easily
spotted from the air.
Body Signals
When an aircraft is close enough for the pilot to see you
clearly, use
body movements or positions (Figure
7) to convey a message.
Panel Signals
If you have a life raft cover or sail, or a suitable substitute,
use the symbols
shown in Figure
8 to convey a message.
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Aircraft Acknowledgments
Once the pilot of a fixed-wing aircraft has sighted you, he will
normally
indicate he has seen you by flying low, moving the plane, and
flashing
lights as shown in Figure
9. Be ready to relay other messages to the
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pilot once he acknowledges that he received and understood your
first
message. Use a radio, if possible, to relay further messages. If
no radio
is available, use the codes covered in the previous paragraphs.
AIRCRAFT VECTORING
PROCEDURES
If you can contact a friendly aircraft with a radio, guide the
pilot to your
location. Use the following general format to guide the pilot:
Mayday, Mayday.
Call sign (if any).
Name.
Location.
Number of survivors.
Available landing sites.
Any remarks such as medical aid or other specific types of help
needed immediately.
Simply because you have made contact with rescuers does not mean
you
are safe. Follow instructions and continue to use sound survival
and evasion
techniques until you are actually rescued.
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