What is Distress Signal?

Information about Distress Signal

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A distress signal is an internationally recognized means of obtaining help. Distress signals are commonly made by using a radio, displaying a visual object, or making noise from a distance.

A distress signal indicates that a person or group of people, ship, aircraft, or other vehicle is threatened by grave and imminent danger and requests immediate assistance. Use of distress signals in other circumstances may be against local or international law.

Maritime distress signals

Distress signals at sea are defined in the International Regulations for Preventing Collisions at Sea and in the International Code of Signals. They must only be used where there is grave and imminent danger to life. Other urgent signals should be sent using a pan-pan message.

Distress can be signalled by any of the following means:
  • sending a Mayday message by radio on VHF channel 16 (156.8 MHz) or HF on 2182 kHz
  • sending the Morse code group SOS
  • using red flares (either hand-held or parachute flares)
  • emitting orange smoke from a canister
  • showing flames on the vessel (as from a burning tar barrel, oil barrel, etc)
  • slowly and repeatedly raising and lowering arms outstretched to each side
  • a continuous sounding with any fog-signalling apparatus
  • a gun or other explosive signal fired at intervals of about a minute
  • the International maritime signal flags NC
  • a signal consisting of a square flag having above or below it a ball or anything resembling a ball
In addition, distress can be signalled using automated radio signals, eg from an Emergency Position-Indicating Radio Beacon (EPIRB).

If none of the above are available, attention can be drawn by anything unusual, e.g., a jib sail hoisted upside down.

Flags

Inverted national flags are no longer commonly used as distress signals. It is difficult or impossible to determine when the flags of many countries (such as  the United Kingdom or  Argentina) are inverted, or the viewer may not be familiar with the flag and may not realise it is not upright. If a national flag is all that is available, distress may be indicated by tying a knot in it, making it into a wheft[1].

Aviation distress signals

The civilian aircraft emergency frequency is 121.5 MHz. Military aircraft use 243 MHz (which is a harmonic of 121.5 MHz, and therefore civilian beacons transmit on this frequency as well). Aircraft can also signal an emergency by setting one of several special transponder codes, such as 7700.

A "triangular distress pattern" is a rarely-used flight pattern flown by aircraft in distress but without radio communications. The standard pattern is a series of 120° turns.

Mountain distress signals

The recognised mountain distress signals are based on groups of three (six in the UK). A distress signal can be 3 fires or piles of rocks in a triangle, three blasts on a whistle, or three flashes of a light, in succession followed by a one minute pause and repeated until a response is received. Three blasts or flashes is the appropriate response.

In the Alps, the recommended way to signal distress is the Alpine distress signal: give six signals within a minute, then pause for a minute, repeating this until rescue arrives. A signal may be anything visual (waving clothes or lights, use of a signal mirror) or audible (shouts, whistles, etc.). The rescuers acknowledge with three signals per minute. To communicate with a helicopter in sight, raise both arms (forming the letter Y) to indicate "Yes" or "I need help" and stretch one arm up and one down (imitating the letter N) for "No" or "I do not need help". If semaphore flags are available, they can possibly be used to communicate with rescuers.

See also

External links

Timeline (Canadian version)

  • In September 2004, Litonjua (who had retained her position in the promotions department of the Rogers-owned OMNI Television) decided that her schedule was too hectic, and resigned as co-host.

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Radio is the wireless transmission of signals, by modulation of electromagnetic waves with frequencies below those of visible light. Electromagnetic radiation travels by means of oscillating electromagnetic fields that pass through the air and the vacuum of space.
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ship is a large watercraft capable of offshore navigation. Ships may be operated by:
  • Governments (military, rescue, research, transportation)
  • Private companies and institutions (transportation, offshore resources, research)
  • Individuals (large yachts, research).

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aircraft is a vehicle which is able to fly through the air (or through any other atmosphere). All the human activity which surrounds aircraft is called aviation. (Most rocket vehicles are not aircraft because they are not supported by the surrounding air).
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The International Regulations for Preventing Collisions at Sea 1972 (COLREGS) are published by the International Maritime Organization (IMO), and set out the "rules of the road" to be followed by ships and other vessels at sea.
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The International Code of Signals (INTERCO) is a signal code to be used by merchant and naval vessels to communicate important messages about the state of a vessel and the intent of its master or commander when there are language barriers.
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pan-pan means that there is an emergency on board a boat, ship, aircraft or other vehicle but that, for the time being at least, there is no immediate danger to anyone's life or to the vessel itself.
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Mayday is an emergency code word used internationally as a distress signal in voice procedure radio communications, derived from the French venez m'aider, meaning "come [to] help me.
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Very high frequency (VHF) is the radio frequency range from 30 MHz to 300 MHz. It is also known as the meter band or meter wave as the wavelengths range from ten to one meters.
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The radio frequency of 2182 kilohertz (kHz) is the international calling and distress frequency for voice maritime communication (radiotelephony) on the marine MF bands. It is analogous to Channel 16 on the marine VHF band.
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Morse code is a method for transmitting telegraphic information, using standardized sequences of short and long elements to represent the letters, numerals, punctuation and special characters of a message.
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SOS is the commonly used description for the International Morse code distress signal (· Â· Â· — — — Â· Â· Â·). This distress signal was first adopted by the German government in radio regulations effective April 1, 1905,
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flare is a type of pyrotechnic that produces a brilliant light or intense heat without an explosion. Flares are used for signaling, illumination, or defensive countermeasures in civilian and military applications.
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Foghorns are a navigation aid for mariners. In foggy conditions, when visual navigation aids such as lighthouses are obscured by the weather, foghorns provide an audible warning of rocks, headlands, or other dangers to shipping.
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The system of international maritime signal flags is a way of representing individual letters of the alphabet in signals to or from ships. It is a component of the International Code of Signals.
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distress radiobeacons, also collectively known as distress beacons, emergency beacons, or simply, beacons, are tracking transmitters which aid in the detection and location of boats, aircraft, and/or persons in distress.
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A jib is a triangular staysail set ahead of the foremost mast of a sailing boat. Its tack is fixed to the bowsprit, to the bow, or to the deck between the bowsprit and the foremost mast. Jibs and spinnakers are the two main types of headsails on a modern yacht.
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national flag is a flag that symbolises a country. The flag is flown by the government, but usually can be flown by citizens of that country as well.

Both public and private buildings such as schools and courthouses often fly the national flag.
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Motto
"Dieu et mon droit" [2]   (French)
"God and my right"
Anthem
"God Save the Queen" [3]
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Motto
En unión y libertad   (Spanish)
"In Union and Freedom"
Anthem
Himno Nacional Argentino
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The aircraft emergency frequency (also known as guard) is a frequency used on the aircraft radio band reserved for emergency communications for aircraft in distress. The frequencies are 121.5 MHz for civilian, also known as International Air Distress (IAD) and 243.
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harmonic of a wave is a component frequency of the signal that is an integer multiple of the fundamental frequency. For example, if the frequency is f, the harmonics have frequency 2f, 3f, 4f, etc.
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ALPS can refer to:
  • Autoimmune lymphoproliferative syndrome
  • The Airport Logistics Park of Singapore




Countries Austria, France,
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The Alpine distress signal is a distress signal in the case of mountain emergency, an emergency in alpine areas. There are also special emergency call numbers, for use with the telephone service by which the emergency services can be contacted.
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Mayday is an emergency code word used internationally as a distress signal in voice procedure radio communications, derived from the French venez m'aider, meaning "come [to] help me.
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Mr. Skylight paged over the PA system is an alert for the crew onboard and means there is a minor emergency somewhere.[1]
  • Mr. Mob means man overboard.
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    • distress radiobeacons, also collectively known as distress beacons, emergency beacons, or simply, beacons, are tracking transmitters which aid in the detection and location of boats, aircraft, and/or persons in distress.
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    distress radiobeacons, also collectively known as distress beacons, emergency beacons, or simply, beacons, are tracking transmitters which aid in the detection and location of boats, aircraft, and/or persons in distress.
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    The Global Maritime Distress Safety System (GMDSS) is an internationally agreed-upon set of safety procedures, types of equipment, and communication protocols used to increase safety and make it easier to rescue distressed ships, boats and aircraft.
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    Beginning in the early 20th century, the radio frequency of 500 kilohertz (kHz) has been an international (calling and) distress frequency for Morse code maritime communication.
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