RIC-22 — General Radiotelephone Operating Procedures

5. Emergency Communications

5.1 Emergency Conditions

Emergency conditions are classified in accordance with the degree of danger or hazard as follows:

Distress: A condition of being threatened by grave and/or imminent danger and requiring immediate assistance.

Urgency: A condition concerning the safety of an aircraft or other vehicle, or of someone on board or within sight, but which does not require immediate assistance.

Safety: An indication that the station calling is about to transmit a message concerning the safety of navigation or important meteorological warnings.

Distress, urgency and safety procedures are outlined in regulations and are designed primarily for the aeronautical and maritime services. Use of these types of communications in the land mobile service is very rare.

Since detailed procedures for distress, urgency and safety communications have not been expressly developed for use in the land-mobile service, a brief outline of procedures for providing safety-related communications is given in the following sections.

5.2 Distress Communications

Distress communications should be conducted in accordance with the procedures outlined in this section. These procedures shall not, however, prevent a station in distress from making use of any means at its disposal to attract attention, to make known its position, and to obtain assistance.

5.2.1 Frequencies to Be Used

The first transmission of the distress call and message by a station should be made on the frequency in use at the time. If the station is unable to establish communications on the frequency in use, the distress call and message should be repeated on any other frequency available in an effort to establish communications with any other station.

5.2.2 Distress Signal

In radiotelephony, the spoken word for distress is "MAYDAY", and it should be used at the commencement of the first distress communication.

The distress signal indicates that a person or station sending the signal is:

  1. threatened by grave and imminent danger and requires immediate assistance, or
  2. aware that an aircraft, ship, other station or person is threatened by grave and imminent danger and requires immediate assistance.
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5.2.3 Priority of Distress

The distress call has absolute priority over all other transmissions. All stations which hear it shall immediately cease any transmission capable of interfering with distress traffic and continue to listen on the frequency used for the distress call.

5.2.4 Control of Distress Traffic

The control of distress traffic is the responsibility of the station in distress or of the station which relays the distress message. These stations may, however, delegate the control of distress traffic to another station.

5.2.5 Distress Call

The distress call identifies the station in distress, and such calls shall only be sent on the authority of the person in command of the station. The distress call should comprise:

  1. the distress signal "MAYDAY" spoken three times;
  2. the words "THIS IS";
  3. the call sign of the station in distress spoken three times.

Example:
MAYDAY, MAYDAY, MAYDAY
THIS IS
PIPER CHARLIE FOXTROT X-RAY QUEBEC QUEBEC
PIPER CHARLIE FOXTROT X-RAY QUEBEC QUEBEC
PIPER CHARLIE FOXTROT X-RAY QUEBEC QUEBEC

The distress call shall not be addressed to a particular station and acknowledgement of receipt shall not be given before the distress message is sent.

5.2.6 Distress Message

The distress message shall follow the distress call as soon as possible.

The distress message should include as many as possible of the following elements spoken distinctly and, if possible, in the following order:

  1. the distress signal "MAYDAY";
  2. the call of the sign station in distress (once);
  3. the nature of the distress condition and the kind of assistance required (i.e. what has happened);
  4. the intentions of the person in command;
  5. the particulars of its position (location, airspeed, altitude, heading);
  6. the number of persons on board and injuries (if applicable);
  7. any other information that might facilitate the rescue;
  8. the call sign of the station in distress.

Example: MAYDAY
PIPER CHARLIE FOXTROT X-RAY QUEBEC QUEBEC
STRUCK BY LIGHTNING
DITCHING AIRCRAFT
POSITION: 20 MILES EAST OF WINNIPEG
ALTITUDE: 1500 FEET
AIRSPEED: 125 KNOTS
HEADING: 270 T
ONE PERSON ON BOARD
PIPER CHARLIE FOXTROT X-RAY QUEBEC QUEBEC

Note: If the station operator can transmit the distress message immediately after the distress call, then items 1 and 2 may be omitted from the message.

5.2.7 Repetition of a Distress Message

The distress message shall be repeated at intervals by the station in distress until an answer is received or until it is no longer feasible to continue. The intervals between repetitions of the distress message shall be sufficiently long enough to allow time for stations receiving the message to reply.

Any station that has heard an unacknowledged distress message and is not in a position to render assistance, shall take all possible steps to attract the attention of other stations that are in a position to assist.

In addition, all necessary steps shall be taken to notify the appropriate search and rescue authorities of the situation.

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5.2.8 Action by Station in Distress

When a station is threatened by grave and imminent danger, and requires immediate assistance, the person in command should direct appropriate action as follows:

  1. transmit the distress call;
  2. transmit the distress message;
  3. listen for acknowledgement of receipt;
  4. exchange further distress traffic as applicable;
  5. activate automatic emergency equipment (emergency locator transmitter - ELT) if available and when appropriate.

5.2.9 Action by Stations Other than the Station in Distress

A station that is not in distress should transmit the distress message when:

  1. the station in distress is not in a position to transmit the message, or
  2. the person in command of the station that intervenes believes that further help is necessary.

When a distress message is received and it is known that the affected station is not in the immediate vicinity, sufficient time should be allowed before the distress message is acknowledged. This will permit stations nearer to the station in distress to reply.

5.2.10 Action by Other Stations Hearing a Distress Message

1. Continue to monitor the frequency on which the distress message was received and, if possible, establish a continuous watch on appropriate distress and emergency frequencies.

2. Notify any station with direction-finding or radar facilities and request assistance unless it is known that this action has been, or will be, taken by the station acknowledging receipt of the distress message.

3. Cease all transmissions that may interfere with the distress traffic.

5.2.11 Distress Traffic

Distress traffic consists of all transmissions relative to the immediate assistance required by the station in distress. Essentially, all transmissions made after the initial distress call are considered as distress traffic. In distress traffic, the distress signal "MAYDAY" spoken once, shall precede all transmissions. This procedure is intended to alert stations not aware of the initial distress call and now monitoring the distress channel that traffic heard relates to a distress situation.

Any station in the land mobile, aeronautical, or maritime mobile service that has knowledge of distress traffic and cannot itself assist the station in distress shall follow such traffic until it is evident that assistance is being provided. All stations that are aware of distress traffic, and that are not taking part in it, are forbidden to transmit on the frequencies being used for distress traffic until a message is received indicating that normal working traffic may be resumed (cancellation of distress).

5.2.12 Acknowledgement of Receipt of a Distress Message

The acknowledgement of receipt of a distress message shall be given in the following form:

  1. the distress signal "MAYDAY"
  2. the call sign of the station in distress (spoken three times);
  3. the words "THIS IS";
  4. 4. the call sign of the station acknowledging receipt (spoken three times);
  5. the words "RECEIVED MAYDAY".

Example: MAYDAY
PIPER CHARLIE FOXTROT X-RAY QUEBEC QUEBEC
PIPER CHARLIE FOXTROT X-RAY QUEBEC QUEBEC
PIPER CHARLIE FOXTROT X-RAY QUEBEC QUEBEC
THIS IS WINNIPEG TOWER
WINNIPEG TOWER
WINNIPEG TOWER
RECEIVED MAYDAY

5.2.13 Action by Stations Acknowledging Receipt of a Distress Message

  1. Forward information immediately to the appropriate search and rescue agencies or organizations.
  2. Continue to monitor the frequency on which the distress message was received and, if possible, any other frequency that may be used by the station in distress.
  3. Notify any station with direction-finding or radar facilities that may be of assistance, etc.
  4. Cease all transmissions that may interfere with the distress traffic.
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5.2.14 Relay of a Distress Message

A distress message repeated by a station other than the station in distress shall transmit a signal comprised of:

  1. the signal "MAYDAY RELAY" (spoken three times);
  2. the words "THIS IS";
  3. the call sign of the station relaying the message (spoken three times);
  4. the distress signal "MAYDAY" (once);
  5. the particulars of the station in distress such as its location, the nature of distress, the number of persons on board, etc.

Example: MAYDAY RELAY, MAYDAY RELAY, MAYDAY RELAY
THIS IS
CESSNA CHARLIE NOVEMBER JULIETT INDIA
CESSNA CHARLIE NOVEMBER JULIETT INDIA
CESSNA CHARLIE NOVEMBER JULIETT INDIA
MAYDAY
PIPER CHARLIE FOXTROT X-RAY QUEBEC QUEBEC
STRUCK BY LIGHTNING
DITCHING AIRCRAFT
POSITION: 20 MILES EAST OF WINNIPEG
ALTITUDE: 1500 FEET
AIRSPEED: 125 KNOTS
HEADING: 270 DEGREES
ONE PERSON ON BOARD
PIPER CHARLIE FOXTROT X-RAY QUEBEC QUEBEC

5.2.15 Imposition of Silence

The station in distress, or the station in control of distress traffic, may impose silence on all stations in the area or on any station that interferes with the distress traffic. It shall address these instructions to "all stations", or to one station only as appropriate.

The station in distress, or the station in control, shall use the expression "SEELONCE MAYDAY".

If it is believed to be essential, other stations near the station in distress may also impose silence during a distress situation by using the international expression "SEELONCE DISTRESS".

Should radio silence be imposed during a distress situation, all transmissions shall cease immediately except for those stations involved in distress traffic.

Examples: Imposition of silence on a specific station by the station in distress.
(Cessna C-FNJI is causing interference to distress traffic.)

CESSNA CHARLIE FOXTROT NOVEMBER JULIETT INDIA
THIS IS
PIPER CHARLIE FOXTROT X-RAY QUEBEC QUEBEC
SEELONCE MAYDAY
OUT

Imposition of silence on all stations by a station other than the station in distress.

ALL STATIONS, ALL STATIONS, ALL STATIONS
THIS IS
CESSNA CHARLIE FOXTROT NOVEMBER JULIETT INDIA
SEELONCE DISTRESS
OUT

5.2.16 Cancellation of Distress

When a station is no longer in distress, or when it is no longer necessary to observe radio silence (i.e. the rescue operation has concluded), the station that controlled the distress traffic shall transmit a message addressed to "ALL STATIONS" on the distress frequency(ies) used, advising that normal operation may resume. The proper procedure for cancelling a distress message is:

  1. the distress signal "MAYDAY" (once);
  2. the words "HELLO ALL STATIONS" (three times);
  3. the words "THIS IS";
  4. the name or call sign of the station transmitting the message;
  5. the filing time of the message;
  6. the call sign of the station in distress (once);
  7. the words "SEELONCE FEENEE";

Example:
MAYDAY
HELLO ALL STATIONS, HELLO ALL STATIONS, HELLO ALL STATIONS
THIS IS
WINNIPEG TOWER
TIME 1630 ZULU
PIPER CHARLIE FOXTROT X-RAY QUEBEC QUEBEC
SEELONCE FEENEE
OUT

Note: The procedure outlined above is mainly for the benefit of other stations so they can resume regular service. To ensure that search and rescue stations are advised that a station is no longer in distress, a normal call to the nearest rescue coordination centre detailing the reasons for cancelling the distress call MUST be made.