6. Emergency Communications

6.1 Emergency Conditions

In the aeronautical service, an emergency condition is 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.

6.2 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, make known its position and obtain assistance.

6.3 Frequencies to be Used

The first transmission of the distress call and message by an aircraft should be made on the air-ground frequency in use at the time. If the aircraft is unable to establish communications on the frequency in use, the distress call and message should be repeated on the aeronautical emergency frequency (121.5 MHz), or any other frequency available, in an effort to establish communications with any aeronautical ground station or other aircraft station.

6.4 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 or other vehicle is threatened by grave and imminent danger and requires immediate assistance.

6.5 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.

6.6 Control of Distress Traffic

The control of distress traffic is the responsibility of the aircraft in distress or of the station which relays the distress message. These stations may, however, delegate the control of distress traffic to another station, such as an aeronautical station, which normally has a very efficient interface with air traffic control (ATC) and all search and rescue (SAR) organizations.

6.7 Distress Call

The distress call identifies the station in distress, and such calls shall be sent only 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 aircraft in distress spoken three times.

Example:

MAYDAY, MAYDAY, MAYDAY

THIS IS

PIPER FOXTROT X-RAY CHARLIE CHARLIE

PIPER FOXTROT X-RAY CHARLIE CHARLIE

PIPER FOXTROT X-RAY CHARLIE CHARLIE

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

6.8 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 sign of the station in distress (once);

3. the nature of the distress condition and kind of assistance required (i.e. what has happened);

4. the intentions of the person in command;

5. the particulars of its position (airspeed, altitude, heading);

6. the number of persons on board and injuries (if applicable);

7. any other information that may facilitate rescue;

8. the call sign of the station in distress.

Example:

MAYDAY

PIPER 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 FOXTROT X-RAY QUEBEC QUEBEC

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

6.9 Repetition of a Distress Message

The distress message shall be repeated at intervals by the aircraft 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 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.

6.10 Action by Station in Distress

When an aircraft 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 acknowledgment of receipt;

4. exchange further distress traffic as applicable;

5. activate automatic emergency equipment (i.e. emergency locator transmitter (ELT)) if available and when appropriate.

6.11 Action by Stations Other than the Station in Distress

An aircraft 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 not in distress believes that further help is necessary; or

3. although not in a position to render assistance, the aircraft station has heard a distress message which has not been acknowledged.

When a distress message is received and it is known that the aircraft 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.

6.12 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.

6.13 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 aeronautical 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).

6.14 Acknowledgment of Receipt of a Distress Message

The acknowledgment 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. the call sign of the station acknowledging receipt (spoken three times);

5. the words "RECEIVED MAYDAY".

Example:

MAYDAY

PIPER FOXTROT X-RAY QUEBEC QUEBEC

PIPER FOXTROT X-RAY QUEBEC QUEBEC

PIPER FOXTROT X-RAY QUEBEC QUEBEC

THIS IS

WINNIPEG TOWER

WINNIPEG TOWER

WINNIPEG TOWER

RECEIVED MAYDAY

6.15 Action by Stations Acknowledging Receipt of a Distress Message

1. Immediately acknowledge the distress message.

2. Take control of the communications, or, specifically and clearly transfer that responsibility, advising the aircraft if a transfer is made.

3. Take immediate action to ensure that all necessary information is provided as soon as possible to the Air Traffic Service (ATS) unit concerned, and the aircraft operating agency concerned (or its representative).

4. 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.

5. Warn other stations, as appropriate, in order to prevent the transfer of aeronautical traffic to the frequency of the distress communication.

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

6.16 Relay of a Distress Message

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

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, nature of distress, number of persons on board, etc.

Example:

MAYDAY RELAY, MAYDAY RELAY, MAYDAY RELAY

THIS IS

CESSNA NOVEMBER JULIETT INDIA

CESSNA NOVEMBER JULIETT INDIA

CESSNA NOVEMBER JULIETT INDIA

MAYDAY

PIPER 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 FOXTROT X-RAY QUEBEC QUEBEC

6.17 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 use the international expression "SEELONCE DISTRESS".

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

Example:

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

CESSNA FOXTROT NOVEMBER JULIETT INDIA

THIS IS

PIPER 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 FOXTROT NOVEMBER JULIETT INDIA

SEELONCE DISTRESS

OUT

6.18 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 working 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 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 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 aeronautical station detailing the reasons for cancelling the distress call MUST be made.

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7. Urgency Communications

7.1 Urgency Signal

The urgency signal indicates that the station calling has a very urgent message to transmit concerning the safety of an aircraft, ship or other vehicle, or the safety of a person, but which does not require immediate assistance and shall be sent only on the authority of the person in charge of the station.

The urgency signal is "PAN PAN" spoken three times. It should be used at the beginning of the first urgency communication.

The urgency signal and the urgency message may be addressed to all stations or to a specific station.

7.2 Priority

The urgency signal has priority over all other communications except distress.

Stations that hear the urgency signal shall continue to listen for at least three minutes on the frequency which the signal was heard. After that, if no urgency message has been heard, an aeronautical ground station should, if possible, be notified of the receipt of the urgency signal and normal working may be resumed. All stations that hear the urgency signal must take care not to interfere with the urgency message which follows. Stations that are in communication on frequencies other than those used for the transmission of the urgency message may continue normal work without interruption provided that the urgency message is not addressed to all stations.

7.3 Frequencies to be Used

The first transmission of the urgency signal and message by an aircraft should be made on the air-ground frequency in use at the time. If the aircraft is unable to establish communication on the frequency in use, the urgency signal and message should be repeated on the aeronautical emergency frequency (121.5 MHz), or any other frequency available, in an effort to establish communication with any aeronautical ground or other aircraft station.

7.4 Urgency Message

The urgency signal shall be followed by a message giving further information about the incident that necessitated the use of the urgency signal.

When the urgency message is not addressed to a specific station (i.e. all stations) and is acknowledged by another aircraft or aeronautical ground station, the acknowledging station shall forward the urgency information to the appropriate authorities (i.e. air traffic service unit, airport operating agency or its representative).

The urgency message should contain as many of the following elements as required, spoken distinctly and, if possible, in the following order:

1. the urgency signal "PAN PAN" (three times);

2. the name of the station addressed or the words "ALL STATIONS" (three times);

3. the words "THIS IS";

4. the identification of the aircraft;

5. the nature of the urgency condition;

6. the intentions of the person in command;

7. the present position, flight level or altitude and the heading;

8. any other useful information.

Example:

PAN PAN, PAN PAN, PAN PAN

ALL STATIONS, ALL STATIONS, ALL STATIONS

THIS IS

CESSNA FOXTROT NOVEMBER JULIETT INDIA

LOST, REQUEST RADAR CHECK

POSITION: UNKNOWN

AIRSPEED: 112 KNOTS

ALTITUDE: 1050 FEET

CESSNA FOXTROT NOVEMBER JULIETT INDIA

OVER

Example of reply:

PAN PAN

CESSNA FOXTROT NOVEMBER JULIETT INDIA

THIS IS WINNIPEG TOWER

YOUR POSITION IS 20 MILES SOUTH OF WINNIPEG

WINNIPEG TOWER

STANDING BY

7.5 Cancellation of Urgency Message

When the urgency message which calls for action by the stations receiving the message has been transmitted, the station responsible for its transmission shall cancel it as soon as it knows that action is no longer necessary. The cancellation message shall be addressed to "ALL STATIONS".

Example:

PAN PAN

ALL STATIONS, ALL STATIONS, ALL STATIONS

THIS IS

CESSNA FOXTROT NOVEMBER JULIETT INDIA

CESSNA FOXTROT NOVEMBER JULIETT INDIA HAS BEEN POSITIONED AT

20 MILES SOUTH OF WINNIPEG AIRPORT PROCEEDING NORMALLY

CESSNA FOXTROT NOVEMBER JULIETT INDIA

OUT

02. Categories of messages

5.1.8 Categories of messages

The categories of messages handled by the aeronautical mobile service and the order of priority in the establishment of communications and the transmission of messages shall be in accordance with the following table.

Message category and order of priority

Radiotelephony signal

a) Distress calls, distress messages and distress traffic

MAYDAY

b) Urgency messages, including messages preceded by the medical transports signal

PAN, PAN or PAN, PAN MEDICAL

c) Communications relating to direction finding

d) Flight safety messages

e) Meteorological messages

f) Flight regularity messages

Note 1.

Messages concerning acts of unlawful interference constitute a case of exceptional circumstances which may preclude the use of recognized communication procedures used to determine message category and priority.

Note 2.

A NOTAM may qualify for any of the categories or priorities c) to f) inclusive. The decision as to which priority will depend on the contents of the NOTAM and its importance to the aircraft concerned.

5.1.8.1 Distress messages and distress traffic shall be handled in accordance with the provisions of 5.3.

5.1.8.2 Urgency messages and urgency traffic, including messages preceded by the medical transports signal, shall be handled in accordance with the provisions of 5.3.Note.

The term “medical transports” is defined in the 1949 Geneva Conventions and Additional Protocols (see also RR S33 Section III) and refers to “any means of transportation by land, water, or air, whether military or civilian, permanent or temporary, assigned exclusively to medical transportation and under the control of a competent authority of a Party to the conflict”.

5.1.8.3 Communications relating to direction finding shall be handled in accordance with Chapter 6 (Aeronautical Radio Navigation Service).

5.1.8.4 Flight safety messages shall comprise the following:

1) movement and control messages [see PANS-ATM (Doc 4444)];

2) messages originated by an aircraft operating agency or by an aircraft, of immediate concern to an aircraft in flight;

3) meteorological advice of immediate concern to an aircraft in flight or about to depart (individually communicated or for broadcast);

4) other messages concerning aircraft in flight or about to depart.

5.1.8.5 Meteorological messages shall comprise meteorological information to or from aircraft, other than those in 5.1.8.4, 3).

5.1.8.6 Flight regularity messages shall comprise the following:

1) messages regarding the operation or maintenance of facilities essential for the safety or regularity of aircraft operation;

2) messages concerning the servicing of aircraft;

3) instructions to aircraft operating agency representatives concerning changes in requirements for passengers and crew caused by unavoidable deviations from normal operating schedules. Individual requirements of passengers or crew shall not be admissible in this type of message;

4) messages concerning non-routine landings to be made by the aircraft;

5) messages concerning aircraft parts and materials urgently required;

6) messages concerning changes in aircraft operating schedules.

5.1.8.6.1 Air traffic services units using direct pilot- controller communication channels shall only be required to handle flight regularity messages provided this can be achieved without interference with their primary role and no other channels are available for the handling of such messages.

Note.

The messages at 5.1.8.4, 2) and 5.1.8.6, 1) to 6) typify some of the operational control communications defined in Chapter 1.

5.1.8.7 Recommendation. Messages having the same priority should, in general, be transmitted in the order in which they are received for transmission.

5.1.8.8 Inter pilot air-to-air communication shall comprise messages related to any matter affecting safety and regularity of flight. The category and priority of these messages shall be determined on the basis of their content in accordance with 5.1.8.

Source: ICAO Annex 10.2