Study Guide for Radiotelephone Operator’s Restricted Certificate (Aeronautical)

Study Guide for Radiotelephone Operator’s Restricted Certificate (Aeronautical)

General Information

Application

Application to be examined for the Radiotelephone Operator’s Restricted Certificate (Aeronautical) (RORC) should be made to the nearest office of the Department of Communications.  The Department also has approved examiners, engaged in the aeronautical industry, who conduct examinations on behalf of the Department.

Candidate Requirements

The examination may consist of written, practical and oral exercises.  The candidate must satisfy an examiner that he or she:

  1. is capable of operating radiotelephone equipment;
  2. possesses a general knowledge of radiotelephone operation procedures, the international regulations applicable to the aeronautical service, and specifically those regulations relating to safety of life;
  3. possesses a general knowledge of the Radio Act and the regulations made thereunder.

Eligibility

There is no nationality or age restrictions as to who may take the examination for, or hold a RORC.  Candidates must attest that they do not have a disability that would impair their ability to operate a radio station safely.

Documentation

Identification must be presented at the examination.  A driver’s licence, a birth certificate, a baptismal certificate, a Certificate of Canadian Citizenship, or a Canadian Immigration Identification Card will all be accepted as proof of identity.

Regulations

Radio Operator’s Certificate Requirements

A RORC is required by the operator of radiotelephone equipment on board aircraft and at aeronautical land (fixed and mobile) radio stations using aeronautical mobile frequencies.  The radiotelephone equipment at such station shall be of a type that requires only simple external switching and with a power output not exceeding 250 watts (peak envelope power) and where all frequency-determining elements are pre-set within the transceiver.

RORC are issued for life and no revalidation is required.  Please contact the nearest district office if your certificate is lost or requires replacement.

Priorities of Communications—Aeronautical Service

The order of priority for transmission of messages is:

  1. Distress communications.
  2. Urgency communications.
  3. Communications relating to radio direction-finding.
  4. Flight safety messages.
  5. Meteorological messages.
  6. Flight regularity messages.
  7. Messages related to the application of the United Nations Charter.
  8. Government messages for which priority has been expressly requested.
  9. Service communications relating to the working of the telecommunication service or to communications previously exchanged.
  10. All other aeronautical communications.

Secrecy of Communications

Radio operators and all persons who become acquainted with radiocommunications are bound to preserve the secrecy of communications.  No person shall divulge the contents, or even the existence, of communications transmitted, received or intercepted by a radio station, except to the addressee of the message or his accredited agent, or to properly authorized officials of the Government of Canada or a competent legal tribunal, or an operator of a telecommunications system as is necessary for the furtherance of delivery of the communication.  These restrictions do not apply to a message of distress, urgency, safety or to messages addressed to “ALL STATIONS,” that is, weather reports, storm warnings, etc.

Any person who violates the secrecy of communications is liable, on summary conviction, in the case of an individual, to a fine not exceeding five thousand dollars or to imprisonment for a term not exceeding one year, or to both, or, in the case of a corporation, to a fine not exceeding twenty-five thousand dollars.

Control of Communications

In communications between aeronautical ground stations and aircraft stations, the aircraft station shall comply with the instructions given by the ground station in all matters related to the order and time of transmission, the choice of frequency and to the duration and suspension of work.  This does not apply in the cases of distress or urgency communications, where the control of the communications lies with the station initiating the priority call.

The operation of an aircraft station is under the control of the pilot or other person in charge of the station.

In communications between aircraft stations, normally the station called is the controlling station.  If the station called is in agreement with the calling station, it shall transmit an indication that from that moment onwards it will listen on the working frequency or channel announced by the calling station.  However, if the station called is not in agreement with the calling station on the working frequency or channel to be used, it shall transmit an indication of the working frequency or channel to be used.

Examples:

Ground station calling an aircraft (the ground station has control of radiocommunications).

PIPER CHARLIE FOXTROT X-RAY QUEBEC QUEBEC

THIS IS

OTTAWA RADIO

GO AHEAD ON TOWER FREQUENCY ONE TWO TWO DECIMAL ONE OVER

 

Aircraft calling a ground station (the ground station has control of radiocommunications).

OTTAWA RADIO

THIS IS

PIPER CHARLIE FOXTROT X-RAY QUEBEC QUEBEC

ON FREQUENCY ONE TWO TWO DECIMAL ONE OVER

 

One aircraft to another aircraft (the aircraft being called has the control of radiocommunications).

CESSNA CHARLIE FOXTROT X-RAY QUEBEC TANGO

THIS IS

PIPER CHARLIE FOXTROT X-RAY QUEBEC QUEBEC

ON FREQUENCY ONE ONE DECIMAL SEVEN

OVER

 

PIPER CHARLIE FOXTROT X-RAY QUEBEC QUEBEC

THIS IS

CESSNA CHARLIE FOXTROT X-RAY QUEBEC TANGO

CHANGE TO SEARCH AND RESCUE FEQUENCY ONE TWO DECIMAL SIX

OUT

Superfluous Communications and Interference

Communications should be restricted to that necessary for the transmission of authorized messages.  Profane or obscene language is strictly prohibited.

Any person who violates the regulation relative to unauthorized communications or profane language is liable, on summary conviction, in the case of an individual, to a fine not exceeding five thousand dollars or to imprisonment or a term not exceeding one year, or to both, or in the case of a corporation, to a fine not exceeding twenty-five thousand dollars.

All radio stations shall be installed and operated so as not to interfere with or interrupt the working of another radio station.  The only situation under which you may interrupt or interfere with the normal working of another station is when you are required to transmit higher priority call or message, for example, distress, urgency or other priority call or messages.

Any person who, without lawful excuse, interferes with or obstructs any radio communication is liable, on summary conviction, in the case of an individual, to a fine not exceeding five thousand dollars or to imprisonment or a term not exceeding one year, or to both, or in the case of a corporation, to a fine not exceeding twenty-five thousand dollars.

False Distress Signals

Any person who knowingly sends, transmits, or causes to be sent or transmitted any false or fraudulent distress signal, message, call or radiogram of any kind is guilty of an offence and is liable, on summary conviction, in the case of an individual, to a fine not exceeding five thousand dollars or to imprisonment or a term not exceeding one year, or to both, or in the case of a corporation, to a fine not exceeding twenty-five thousand dollars.

Operating Procedure

Speech Transmission Techniques

The efficient use of radio depends to a large extent on the method of speaking and on the articulation of the operator.  As the distinctive sounds of consonants are liable to become blurred in the transmission of speech and as words of similar length containing the same vowel sounds are apt to sound alike, special care is necessary in their pronunciation.

When using radio, the operator should speak all words plainly and each word clearly to prevent words from running together.  Avoid any tendency to shout, to accent syllables, or to talk too rapidly.  The following points should be kept in mind when using radio:

Speed              Keep the rate of speech constant, neither too fast nor too slow.  Remember that the operator receiving your message may have to write it down.

Rhythm           Preserve the rhythm of ordinary conversation.  In separating words so that they are not run together, avoid the introduction of unnecessary sounds such as “er” and “um” between words.

Time and Date

The twenty-four hour clock system should be used to express time in the Aeronautical Service.  Time should be expressed and transmitted by means of four figures, the first two denoting the hour past midnight and the last two the minute past the hour

Examples-              12:45 a.m. is expressed as 0045

                              12:00 noon is expressed as 1200

                              11:45 p.m.  is expressed as 2345

                              12:00 midnight  is expressed as 2400 or 0000

                              1:30 a.m. is expressed as 0130

                              1:45 p.m. is expressed as 1345

                              4:30 p.m. is expressed as 1630

 

Time is usually reference to one standard time zone, Co-ordinated Universal Time (UTC) (formerly referred as Greenwich Mean Time (GMT) to avoid confusion between different time zones.  The letter Z is the accepted abbreviation for UTC.  When operations are conducted solely in one time zone, standard or local time may be used.

Where the date, as well as the time of day is required, a six-figure ground should be used. The first two figures indicate the day of the month and the following four figures indicate the time.

Examples-              Noon (EST) of the 16th day of the month is expressed as 161200E

                                2:45 a.m. (PST) of the 24th day of the month is expressed as 240245P

Phonetic alphabet

The phonetic alphabet is used to avoid confusion when transmitting difficult or unusual words.  The following internationally recognised alphabet should be learned thoroughly so that it is readily available whenever isolated letters or groups of letters are pronounced separately, or when communication is difficult.  Call signs should also be spelled phonetically.

The ITU (International Telecommunication Union) phonetic alphabet is as follows (note that the syllables to be emphasized on in bold type):

Letter

Word

Pronounced as

Letter

Word

Pronounced as

A

Alfa

AL FAH

N

November

NO VEM BER

B

Bravo

BRAHVOH

O

Oscar

OSS CAH

C

Charlie

CHAR LEE

P

Papa

PAH PAH

D

Delta

DELL TAH

Q

Quebec

KEH BECK

E

Echo

ECK OH

R

Romeo

ROW ME OH

F

Foxtrot

FOKS TROT

S

Sierra

SEE AIR RAH

G

Golf

GOLF

T

Tango

TANG GO

H

Hotel

HOH TELL

U

Uniform

YOU NEE FORM

I

India

IN DEE AH

V

Victor

VIK TAH

J

Juliett

JEW LEE ETT

W

Whiskey

WISS KEY

K

Kilo

KEY LOH

X

X-ray

ECKS RAY

L

Lima

LEE MAH

Y

Yankee

YANG KEY

M

Mike

MIKE

Z

Zulu

ZOO LOO

Number are pronounced as follows:

0-            ZE-RO                  

1-            WUN                     

2-            TOO                      

3-            THREE                  

4-            FOW-er

5-            FIFE

6-            SIX

7              SEV-en

8-            AIT

9-            NIN-er

Transmission of Numbers

All numbers except whole thousands should be transmitted by pronouncing each digit separately.  Whole thousands should be transmitted by pronouncing each digit in the number of thousands followed by the word “thousands.”

Examples-        10 becomes one zero

                        75 becomes seven five

100 becomes one zero zero

5,800 becomes five eight zero zero

11,000 becomes one one thousand

68,009 becomes six eight zero zero nine

Numbers containing a decimal point shall be transmitted as above, with the decimal point indicated by the word “decimal.”

Example-                121.5 becomes one two one decimal five

 

Monetary denominations, when transmitted with groups of digits, should be transmitted in the sequence in which they are written

Examples-              $17.25 becomes dollars one seven decimal two five

                                .75 becomes seven five cents

 

Altitude above sea level should be expressed in thousands plus hundreds of feet.  Separate digits shall be used to express flight levels.

Examples -             2700 is two thousand seven hundred

                                FL265 is flight level two six five

 

Aircraft identification flight numbers, aircraft type numbers and wind speed numbers may be expressed in group forms.

Examples-              Flight 320 becomes flight three twenty

                                DC 10 is DC ten

                                Wind 270/10 is wind two seven zero at ten

Time (UTC)

Examples-              0920Z is zero niner two zero zulu

09 is nine minutes past the hour

Aircraft headings are given in groups of three digits.  If operating within the Southern Domestic Airspace, the heading is expressed in degrees “magnetic.”  If operating within the Northern Domestic Airspace, the heading is express in degrees “true.”

Examples-              005 degrees is heading zero zero five

                                350 degrees is heading three five zero

Aerodrome elevations are expressed in feet, prefixed by the expression “field elevation.”

Examples-              150 is field elevation one five zero

                                3500 is field elevation three thousand five zero zero

Procedural Words and Phrases

While it is not practical to set down precise phraseology for all radiotelephone procedures, slang expressions such as “OK,” “REPEAT.” “OVER AND OUT,”            “BREAKER BREAKER,” “COME IN PLEASE,” etc., should not be used.  The following contains procedural words and phrases that should be used where applicable:

WORD OR PHRASE

MEANING

ACKNOWLEDGE

Let me know that you have received and understood this message.

AFFIRMATIVE

Yes, or permission granted.

BREAK

Indicates the separation between portions of the message.  (To be used where there is no distinction between the text and other portions of the message.)

CHANNEL

Change to channel . . before proceeding.

CLEARED

Authorised to proceed under the conditions specified.

CONFIRM

My version is . . .is that correct?

CORRECTION

An error has been made in this transmission (message indicated).  The correct version is . .

DISREGARD

Consider this transmission as not sent.

GO AHEAD

Proceed with your message.

HOW DO YOU READ?

Self-explanatory.

I SAY AGAIN

Self-explanatory (use instead of “I REPEAT”).

MAYDAY

The spoken word for distress communications.

MAYDAY RELAY

The spoken word for the distress relay signal.

MONITOR

Listen on (frequency).

NEGATIVE

No, or that is not correct, or I do not agree.

OUT

Conversation is ended or no response is expected.

OVER

My transmission is ended and I expect a response from you.

PAN PAN

The spoken word for urgency communications.

READ BACK

Repeat all of this message back to me exactly as received after I have given “OVER” (do not use the word “REPEAT”).

ROGER

I have received all of your last transmission.

ROGER NUMBER

I have received your message Number ___.

SAY AGAIN

Self-explanatory. (Do not use the word “REPEAT.”)

STAND BY

I must pause for a few seconds or minutes, please wait.

SEELONCE

International expression to indicate that silence has been imposed on the frequency due to a distress situation.  The aeronautical phrase is “STOP TRANSMITTING.”

SEELONCE FEENEE

Is the international expression for a distress cancellation.  The aeronautical expression is “DISTRESS TRAFFIC ENDED.”

SEELONCE MAYDAY

Is the international expression to inform an individual(s) that a distress situation is in progress.  The command coming from the aircraft in distress.  The aeronautical phrase is “STOP TRANSMITTING—MAYDAY.”

THAT IS CORRECT

Self-explanatory.

VERIFY

Check coding, check text with originator and send correct version.

WILCO

Your instructions received, understood and will be complied with.

WORDS TWICE
  1. As a request: Communication is difficult, please send each word twice.
  2. As information: Since communication is difficult, I will send each word twice.

Call Signs

A distinctive call sign is assigned to radio stations for identification purposes and should be used at least when initial contact is being established and again when the communication is concluded.  Aeronautical call signs should always be pronounced phonetically.

An aircraft’s call sign is the same as the aircraft’s markings.  The call sign or markings are permanently assigned to the aircraft by Transport Canada.

The term “HEAVY” after the call sign is used to identify an aircraft capable of a takeoff weight of 300,000 lbs. or more.  After communication has been established, and when no likelihood of confusion exists, the word “HEAVY” may be omitted.

Canadian Air Carriers

Canadian Air Carriers use their assigned company name as a call sign followed by the flight number, or the last three characters of the aircraft registration, and the word “HEAVY” if applicable.

Example-                AIR CANADA ONE FOUR NINE HEAVY

Canadian Private Civil Registration

Canadian private aircraft use the manufacturer’s name or their type of aircraft, followed by the last four letters of the registration.

Example-                CESSNA-182 GFAC (spoken: CESSNA ONE EIGHT TWO GOLF FOXTROT ALFA CHARLIE)

Ground Stations

Ground station identification is the name of the airport, followed by the type of station.

examples-

Airport traffic control: tower

Ground control position in tower: Toronto ground

Flight service station: Ottawa radio

IFR clearance delivery position: Edmonton clearance delivery

Terminal control position: Vancouver Terminal

Arrival control position: Ottawa Arrival

Departure control position: Winnipeg departure control

Precision radar position: Montreal precision

Aero control centre: Montreal centre

Community aerodrome radio station: Eskimo Point airport radio

Unicom: Unicom

Private ground station: Assigned call sign/place name

 

Multiple Station Call

If more than one station is to be called simultaneously, the identifiers may be transmitted in any convenient sequence followed by the words “THIS IS” and your call sign.  As a general rule, operators replying to a multiple station call should answer in the order that they have been called.

Example-          CESSNA FOXTROT NOVEMBER INDIA LIMA

                         PIPER FOXTROT X-RAY QUEBEC QUEBEC

PIPER GOLF LIMA LIMA DELTA

(All repeated three times if necessary)

THIS IS

TORONTO TOWER (three times if necessary)

Replying

An operator hearing a call directed to his station shall reply as soon as possible and advise the calling station to proceed with his message with the words “GO AHEAD,” or not to proceed with the message with the words “STAND BY,” followed by the anticipated number of minutes of delay.

Example-          PIPER FOXTROT X-RAY QUEBEC QUEBEC

THIS IS

TORONTO TOWER

GO AHEAD

OVER

 

PIPER FOXTROT X-RAY QUEBEC QUEBEC

THIS IS

TORONTO TOWER

STAND BY TWO MINUTES

OVER

When an operator of a station hears a call but is not sure of the identity of the calling station, he should reply immediately using the words “STATION CALLING,” his station’s identification, and the words “SAY AGAIN” and “OVER.”

Example-                STATION CALLING CESSNA FOXTROT NOVEMBER JULIETT INDIA

SAY AGAIN

OVER

 

To terminate communications, simply conclude your transmission with the word “OUT” (which mean “conversation is ended and no response is expected”).

Example-                TORONTO TOWER

THIS IS

PIPER FOXTROT X-RAY QUEBEC QUEBEC

RECEIVED RUNWAY CLEARANCE

OUT

Radiotelephone Calling Procedure

As a general rule, it rests with the aircraft station to establish communication with aeronautical ground station.  For this purpose, the aircraft station may call the aeronautical ground station when it comes within the operational service area of the station.  However, a ground station having traffic for an aircraft station within its operational service area may call that station.

When an aeronautical ground station receives calls from several aircraft stations at practically the same time, it decides the order in which these stations may transmit their traffic.  Its decision shall be based on the priority status of the messages.

Calling

Before transmitting, every operator shall listen for a period long enough to satisfy himself that he will not cause harmful interference to transmissions already in progress.  If such interference seems likely, he shall wait for the first break in the transmission.

The identifier of the station being called is ALWAYS spoken first, followed by the words “THIS IS” and the calling station’s identifier.

A station having a distress or urgency message to transmit is entitled to interrupt a transmission of a lower priority.

Single Station Call

When an operator wishes to establish communication with a specific station, the following items shall be transmitted in the order indicated:

  1. The call sign of the station called (not more than three times, once if radio conditions are good).
  2. The words “THIS IS.”
  3. The call sign of the station calling (not more than three times, once if radio conditions re good).
  4. The frequency on which the station is transmitting.
  5. The invitation to reply (“OVER”).

Example-                TORONTO TOWER (repeated up to three times)

                                THIS IS

                                CESSNA ONE EIGHT FIVE – FOXTROT ALFA DELTA TANGO

                                ON FREQUENCY ONE ONE EIGHT DECIMAL SEVEN

                                OVER

General Call

When an operator wishes to establish communication with any station within range or in an certain area, the call should be made to “ALL STATIONS” using the same procedure as a single station call.

Example-                ALL STATIONS, ALL STATIONS, ALL STATIONS

THIS IS

TORONTO AIR RADIO – (three times if necessary)

Corrections

When an error has been made in transmission, the word “CORRECTION” should be spoken and the correct version transmitted.

Example-                OVER OTTAWA AT TWO SEVEN CORRECTION TWO EIGHT

PROCEED TO DOCK FOUR CORRECTION DOCK FIVE

If the receiving station requires the repetition of a message, the operator should use the words “SAY AGAIN.”  If repetition of only a portion of a message is required, the receiving station should use the following:

  1. SAY AGAIN ALL BEFORE . . (first word satisfactorily received), or
  2. SAY AGAIN . . (           word before missing portion) TO . . (word after missing portion), or
  3. SAY AGAIN ALL AFTER . . (last word satisfactorily received).

Examples-              VANCOUVER RADIO

THIS IS

STINSON FOXTROT ALFA BROVO CHARLIE

SAY AGAIN ALL BEFORE “HANGAR”

OVER

WINNIPEG TOWER

THIS IS

CESSNA FOXTROT PAPA DELTA QUEBEC

SAY AGAIN “ALTITUDE” TO “DESCEND”

OVER

MONTREAL CENTRE

THIS IS

CESSNA FOXTROT X-RAY QUEBEC TANGO

SAY AGAIN ALL AFTER “FLIGHT PLAN”

OVER

Message Handling Procedures

When transmitting a message, the operator should

  1. deliver the radio message clearly and concisely using standard phraseology whenever practical;
  2. plan the content of the message before transmitting;
  3. listen briefly before transmitting to avoid interference with other transmissions.

The message generally consists of four parts:

  1. The call-up
  2. The reply
  3. The message
  4. The acknowledgement or ending

Examples-

 

(call-up by aircraft)              SCHEFFERVILLE RADIO

THIS

PIPER FOXTROT ALFA BRAVO CHARLIE

OVER

 

(reply by ground station)   PIPER FOXTTROT ALFA BRAVO CHARLIE

THIS IS

SCHEFFERVILLE RADIO

GO AHEAD

OVER

 

(message-aircraft)                SCHEFFERVILLE RADIO

THIS IS

PIPER FOXTROT ALFA BRAVO CHARLIE

FOUR MILES AT ONE THOUSAND

LANDING SCHEFFERVILLE

OVER

 

(message-ground)                PIPER FOXTROT ALFA BROVO CHARLIE

THIS IS

SCHEFFERVILLE RADIO

ROGER

WIND – ONE SIX ZERO AT ONE FIVE

ALTIMETER – TWO NINER NINER SEVEN

OVER

 

(acknowledgement-aircraft)                SHEFFERVILLE RADIO

THIS IS

PIPERFOXTROT ALFA BROVO CHARLIE

ROGER

 

On subsequent calls, the words “THIS IS” and “OVER” may be omitted and, if no likelihood of interference exists, the call sign for the station being called may be abbreviated as follows:

 

                “SCHEFFERVILLE RADIO BROVO CHARLIE CONFIRM RIGHT ON SIERRA”

Signal (or Radio) Checks

When your radio station requires a signal (or radio) check, follow this procedure:

  1. Call another aircraft or ground station on any appropriate frequency which will not interfere with the normal working of other aircraft or ground stations, and request a radio check.
  2. The signal check consists of “SIGNAL CHECK 1, 2, 3, 4, 5.  HOW DO YOU READ ME?  OVER.”
  3. Your station identification (call sign) should be transmitted during such test transmissions.
  4. Signal checks should not last more than 10 seconds.
  5. When replying or receiving a reply to a signal check, the following readability scale should be used:
    1. Bad (unreadable)
    2. Poor (readable now and then)
    3. Fair (readable but with difficulty)
    4. Good (readable)
    5. Excellent (perfectly readable)

Communications checks are categorized as follows:

Signal Check-                        If the test is made while the aircraft is airborne.

Pre-flight check-                   If the test is made prior to departure.

Maintenance check-            If the test is made by ground maintenance.

Example-                WATSON LAKE RADIO

                                THIS IS

                                CESSNA FOXTROT ALFA BRAVO CHARLIE

                                SIGNAL CHECK ON FIVE SIX EIGHT ZERO

                                FOXTROT ALFA BRAVO CHARLIE

                                THIS IS

                                WATSON LAKE RADIO

                                READING YOU STRENGTH FIVE

                                OVER

Distress Communications

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 of requiring immediate assistance.

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

Distress Communication

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 obtain assistance.

Frequencies to be used

The first transmission, of the distress call and the message by an aircraft should be made on 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 communication with any ground or other aircraft station.

Distress Signal

In radiotelephony, the spoken word for distress is “MAYDAY.”

The distress signal indicates that the 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.

Distress Call

The distress call 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 aircraft in distress spoken three times.

Example-                MAYDAY, MAYDAY, MAYDAY

                                THIS IS

                                PIPER FOXTROT X-RAY CHARLIE CHARLIE

 

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.

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) organisations.

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:

  1. the distress signal “MAYDAY”;
  2. the call sign of 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 which might facilitate rescue;
  8. the call sign of the station in distress.

Example-                MAYDAY

PIPER FOXTROT X-RAY QUEBEC QUEBEC

POSITION:            20 MILES EAST OF WINNIPEG

ALTITUDE:          1500 FEET

AIRSPEED:           125 KNOTS

HEADING:            270 T

STRUCK BY LIGHTING

DITCHING AIRCRAFT

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.

Repetition of a Distress

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 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.

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 acknowledgement of receipt;
  4. exchange further distress traffic as applicable;
  5. turn on automatic emergency equipment (emergency locator transmitter—ELT) if provided and when appropriate.

Distress Traffic

Distress traffic consists of all transmission 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 which are aware of distress traffic, and which 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 may be resumed (cancellation of distress).

Acknowledgement of Receipt of a Distress Message

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

  1. the call sign of the station in distress;
  2. the words “THIS IS”;
  3. the call sign of the station acknowledging receipt;
  4. the words “RECEIVED MAYDAY.”

Example-                PIPER FOXTROT X-RAY QUEBEC QUEBEC

THIS IS

WINNIPEG TOWER

RECEIVED MAYDAY

Relay of 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 (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

MAYDAY

                                PIPER FOXTROT FOXTROT X-RAY QUEBEC QUEBEC

                                POSITION:            20 MILES EAST OF WINNIPEG

ALTITUDE:          1500 FEET

AIRSPEED:           125 KNOTS

HEADING:            270 T

STRUCK BY LIGHTING

DITCHING AIRCRAFT

ONE PERSON ON BOARD

PIPER FOXTROT X-RAY QUEBEC QUEBEC

Actions by Other Stations

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 which intervenes believes that further help is necessary.

When a distress message is revived 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.

Action by the Station Acknowledging Receipt of a Distress Message

  1. Forward Information immediately to the appropriate search and rescue agencies or organisations.
  2. Continue to guard 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 which may be of assistance . . etc.
  4. Cease all transmission which may interfere with the distress traffic.

Actions by Other Stations Hearing a Distress Message

  1. Continue to guard 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 which may interfere with the distress traffic.

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 which interferes with the distress traffic.

The station in distress, or the station in control, shall use the expression “STOP TRANSMITTING-DISTRESS” or the international expression “SILENCE MAYDAY” or “SEELONCE MAYDAY.”

Other stations imposing silence during a distress situation shall use the expression “STOP TRANSMITTING-DISTRESS” or use the international expression “SILENCE DISTRESS” or “SEELONCE DISTRESS.”

Should radio silence be imposed during a distress situation, all transmission shall cease immediately except from 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 FOXTROT NOVEMBER JULIETT INDIA

THIS IS

PIPER FOXTROT X-RAY QUEBEC QUEBEC

STOP TRANSMITTING-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 JULIETTE INDIA

STOP TRANSMITTING DISTRESS

                                OUT

Cancellation of Distress

When a station is no longer in distress, or when it is no longer necessary to observe radio silence (i.e., rescue operation has concluded), the station that was in distress, the rescue vessel or the station that controlled distress traffic shall transmit a message address to “ALL STATIONS” on the distress frequency(ies) advising that the distress has ended.  The proper procedure for cancelling a distress message is:

  1. the distress signal “MAYDAY” (once);
  2. the words “ALL STATIONS” (three time);
  3. the word “THIS IS”;
  4. the name and/or call sign of the station transmitting the message (three times);
  5. the filing time of the message;
  6. the call sign of the station in distress (once);
  7. the words “DISTRESS TRAFFIC ENDED” or the international expression “SILENCE FINISHED” or “SEELONCE FEENEE.”
  8. a short plain-language description of why the distress situation is being cancelled;
  9. the name or call sign of station transmitting the message;
  10. the word “OUT.”

Example-                MAYDAY

ALL STATIONS, ALL STATIONS, ALL STATIONS

THIS IS

WINNIPEG TOWER

TIME 1630Z

MAYDAY

PIPER FOXTROT X-RAY QUEBEC QUEBEC

DISTRESS TRAFFIC ENDED

PIPER FOXTROT X-RAY QUEBEC QUEBEC LOCATED BY SEARCH AND RESCUE

WINNIPEG TOWER

OUT

 

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

Urgency Communications

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.

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

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

Priority

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

Stations that hear only the urgency signal shall continue to listen for at least three minutes on the frequency on which the signal is heard.  After that, if no urgency message has been heard, stations may resume normal service.  All stations that hear the urgency signal must take care not to interfere with the urgency message that follows it.  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.

Frequencies to Be Used

The first transmission of the urgency 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 communication on the frequency in use, the urgency call 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 ground or other aircraft station.

Urgency Message

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

When the urgency message does not contain a specific address and is acknowledged by an aircraft or aeronautical ground station, that station shall forward the information to the appropriate authorities (air traffic control and search and rescue organisations).

The urgency message should contain as many as required of the following elements 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, the flight level or the 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

POSITION:            UNKNOWN

AIRSPEED:           112 KNOTS

ALTITUDE:          1050 FEET

LOST, REQUEST RADAR CHECK

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

WINIPEG TOWER

 STANDING BY

Cancellation of Urgency Message

When the urgency signal has been used before a message addressed to all station, which call for action by stations receiving the message, 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 POSITION AT 20 MILES SOUTH OF WINNIPEG AIRPORT PROCEEDING NORMALLY

CESSNA FOXTROT NOVEMBER JULIETT INDIA OUT