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CHAPTER 19 - SIGNALING 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.
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 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
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.
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.
These signals are materials or equipment you use
to make your presence known to rescuers.
During darkness, fire is the most effective
visual means for signaling. Build three fires in a triangle (the international
distress signal) or in a 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 19-1). 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.
During daylight, build a smoke generator and use
smoke to gain attention (Figure 19-2). 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.
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.
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
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.
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.
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
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.
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
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.
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 19-4 and 19-5
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.
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.
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.
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
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.
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.
Radios, whistles, and gunshots are some of the
methods you can use to signal your presence to rescuers.
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
Never let the antenna touch your clothing,
body, foliage, or the ground. Such contact greatly reduces the range of the
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.
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.
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.
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.
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 19-6) 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.
When an aircraft is close enough for the pilot to
see you clearly, use body movements or positions (Figure 19-7)
to convey a message.
If you have a life raft cover or sail, or a
suitable substitute, use the symbols shown in Figure 19-8
to convey a message.
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 19-9. Be
ready to relay other messages to the 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.
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).
- 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.