ROC-A Study Guide (Aeronautical Radio) 2026

The ROC-A and the exam

The Restricted Operator Certificate with Aeronautical Qualification (ROC-A) lets you operate radiotelephone equipment on aircraft and at aeronautical ground stations that use aeronautical mobile frequencies. ISED (Innovation, Science and Economic Development Canada) issues it.

Who needs it

• Pilots of aircraft with a radio
• Drone operators who use aeronautical radio
• Airport radio operators
• Ground staff on or near landing strips, such as dispatchers, snow removal crews, fuel truck staff and airport firefighters

The ROC-A covers simple equipment: only simple external switching, all frequency settings preset in the radio, and an output of no more than 250 watts e.r.p. (about 400 watts PEP).

How to get it

1. Study RIC-21, the ISED study guide.
2. Find an accredited examiner with the ISED examiner search or list.
3. Pass the exam. It may include written, practical and oral parts.
4. Your certificate is mailed to you.

• There are no age or nationality limits.
• You must show identification, such as a passport or driver's licence. The examiner decides what is accepted.
• You must state that you have no disability that would stop you from operating a radio station safely.
• The ROC-A is issued for life and does not need to be revalidated.

Rules: priority, privacy and control

Order of priority

1. Distress messages
2. Urgency messages
3. Radio direction-finding communications
4. Flight safety messages
5. Meteorological messages
6. Flight regularity messages
7. Messages about United Nations Charter applications
8. Government messages for which priority was requested
9. Service communications about the radio service
10. All other aeronautical communications

Privacy of communications

If you hear a message meant for someone else, you must not reveal what it said, or even that it was sent, except to people the law allows. This rule does not apply to distress, urgency or safety messages, or to messages sent to ALL STATIONS.

Who controls the exchange

• Between an aircraft and a ground station, the ground station is normally in control. The aircraft follows its instructions on timing, frequency and length of calls.
• Between two aircraft, the station being called is in control.
• In distress or urgency traffic, control rests with the station that started the priority call.

Things you must not do

• Send superfluous (unneeded) messages or use profane or obscene language.
• Interfere with other stations, except with a higher-priority call such as distress.
• Knowingly send a false distress signal. This is an offence under the Radiocommunication Act.
• Operate a station that needs a licence without one. A radio station licence, or a copy, must be shown to an inspector on request.

Speaking clearly and giving the time

• Speak each word plainly, without shouting.
• Keep a steady speed. The other operator may be writing your message down.
• Use a normal rhythm and avoid filler sounds such as "um" and "er".

The 24-hour clock and UTC

Times use four figures: hours, then minutes, counted from midnight. Aeronautical radio normally uses UTC (also called Zulu). Local time may be used only when all operations are within one time zone.

A date and time group has six figures. The first two are the day of the month and the last four are the time. For example, 161200 is the 16th at 1200.

Phonetic alphabet and numbers

Use the ITU phonetic alphabet for single letters, hard words, poor conditions and all aeronautical call signs.

Alfa, Bravo, Charlie, Delta, Echo, Foxtrot, Golf, Hotel, India, Juliett, Kilo, Lima, Mike, November, Oscar, Papa, Quebec, Romeo, Sierra, Tango, Uniform, Victor, Whiskey, X-ray, Yankee, Zulu.

How to say numbers

Procedure words

Standard words keep messages short and clear. Do not use slang such as OK, REPEAT, TEN-FOUR, OVER AND OUT, BREAKER BREAKER or COME IN PLEASE.

Call signs

A call sign identifies a station. Use it at least at the start and end of each communication. Transport Canada assigns aircraft registrations and call signs.

• Air carriers: company name, then the flight number or the last three characters of the registration.
• Private aircraft: maker's name or aircraft type, then the last four letters of the registration, said phonetically.
• Ground stations: the place name, then a word for the service.

Calling, replying and radio checks

1. Listen first, long enough to be sure you will not interfere.
2. Say the called station's call sign.
3. Say THIS IS.
4. Say your own call sign.
5. Give the frequency you are on, then say OVER.

• In good conditions, each call sign is said once. In poor conditions, up to three times.
• Reply as soon as you can with GO AHEAD, or STAND BY and the expected wait in minutes.
• Not sure who called? Say STATION CALLING, your call sign, SAY AGAIN, OVER.
• If several stations call at once, the ground station decides the order by priority.
• To fix an error, say CORRECTION, repeat the last correct word or phrase, then the correct version.
• To get part of a message repeated, use SAY AGAIN ALL BEFORE, SAY AGAIN ALL AFTER, or SAY AGAIN (word) TO (word).

Signal checks

Use a frequency that will not disrupt traffic and keep each check to 10 seconds or less. Replies use a readability scale of 1 to 5.

Distress: MAYDAY

Distress means grave or imminent danger that needs immediate assistance. The spoken distress signal is MAYDAY. A distress call has absolute priority and may be sent only on the authority of the person in command.

Make the first call on the air-ground frequency in use. If there is no answer, use 121.5 MHz, the aeronautical emergency frequency, or any other frequency available.

Distress call and message

1. MAYDAY, MAYDAY, MAYDAY
2. THIS IS
3. Your call sign, three times
4. The nature of the distress and the help needed
5. The intentions of the person in command
6. Position, airspeed, altitude and heading
7. Number of persons on board and any injuries
8. Any other useful information, then your call sign again

• Other stations must stop transmissions that could interfere and keep listening.
• An acknowledging station says MAYDAY, the aircraft's call sign three times, THIS IS, its own call sign three times, and RECEIVED MAYDAY.
• A station passing on a distress message for someone else uses MAYDAY RELAY.
• SEELONCE MAYDAY imposes silence. It is used by the station in distress or the station controlling distress traffic. Another station near the distress may use SEELONCE DISTRESS.
• SEELONCE FEENEE means the distress is over.

Urgency: PAN PAN

Urgency means the safety of an aircraft, vehicle or person is at risk, but immediate help is not needed. The signal is PAN PAN, said three times. Urgency ranks above everything except distress.

• Use the frequency in use first, then 121.5 MHz if needed.
• Stations that hear PAN PAN must keep listening for at least three minutes.
• The message gives the station addressed (or ALL STATIONS), THIS IS, your identification, the problem, your intentions, your position, altitude and heading, and other useful details.
• The station that sent the urgency message must cancel it when help is no longer needed.

Equipment care

• Keep microphone and antenna connections tight and clean.
• Watch for shorts (bare wires touching) and open wires (broken inside the insulation).
• Coat exposed connections, for example with silicone, to keep out water and stop corrosion.
• Never fit a fuse with a higher rating. Find and fix the fault first, and keep your hands dry.